PCB Rogowski coil

Disclosed is a PCB Rogowski coil, comprising two groups of first coils and second coils which are connected in series and have opposite winding directions, wherein the first coil and the second coil respectively contain a plurality of wire turns. One wire turn of the first coil comprises an inlet wire, a winding wire and an outlet wire. The winding wires of each wire turn of the first coil are arranged in radially parallel with each other. The winding wires are respectively arranged on both the upper surface and the lower surface of a PCB board, with the inlet wire passes through a via hole on the PCB board and is connected to the winding wire. The interference of an external magnetic field is therefore markedly eliminated, and the anti-external interference capability of a Rogowski coil is improved.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a continuation of International Application No. PCT/CN2014/078242, filed in the Chinese Patent Office on May 23, 2014, which is a continuation of Chinese Application No. 201310239226.2, filed on Jun. 18, 2013, and 201310289012.6, filed on Jul. 11, 2013, the entire contents of which are incorporated herein by reference.

BACKGROUND

The present disclosure refers to the electronic technical field, especially a PCB (printed circuit board) Rogowski coil.

A Rogowski coil is the one formed by uniformly winding a wire on a frame made of a nonmagnetic material with uniform section. The Rogowski coil, featured with light weight, wide frequency band and good linearity and no magnetic saturation, has been universally used in a current measuring device. According to whether the Rogowski coil can be opened during measurement, it can be divided into two types, i.e., a closed Rogowski coil and an opened Rogowski coil. The closed Rogowski coil is shown inFIG. 1.

The closed Rogowski coil100includes the following parts:

(2) Ring winding110wound from signal output end130to the end of ring winding120

(3) Return wire turn155from the end of ring winding120to signal output end125along the center of ring winding

When the closed Rogowski coil100is used for current measurement, a current-carrying conductor105is required to pass through the closed Rogowski coil100first. The current-carrying conductor105is required to pass through the center of the closed Rogowski coil100vertically with the centers of the current-carrying conductor105and closed Rogowski coil100in superposition to ensure measurement accuracy. The current-carrying conductor105is surrounded by the closed Rogowski coil100. When the alternating current I(t) to be measured flows through the current-carrying conductor105, it generates an AC magnetic field around the current-carrying conductor, and the magnetic lines are approximated as the circle centered in the center of current-carrying conductor105. Centers of various cycles of wire turns of the ring winding110for closed Rogowski coil100are in one of the circular magnetic lines. The sectional areas corresponding to various wire turns of the ring winding110for closed Rogowski coil100are equal. Each wire turn section direction of the ring winding110is in line with the normal direction of magnetic lines (i.e., radius direction of the section center is pointing to the center of the current-carrying conductor105), and is vertical to the tangential direction of the circular magnetic lines. Therefore, the magnetic flux φi(t) of each ring winding wire turn of the closed Rogowski coil is ensured to be approximately equal with the magnetic flux in direct proportion to the current.
Φi(t)=L·I(t)  (1)

The alternating current I(t) to be measured causes the change on magnetic flux within the volume encircled by the ring winding of the closed Rogowski coil100, which can be converted into voltage signals in proportion to differential of the total magnetic flux by the closed Rogowski coil100, i.e. the output voltage signal V(t) between output ends125and130of the closed Rogowski coil100.

After simplification, the output voltage signal V(t) of the closed Rogowski coil is approximately in proportion to the differential of alternating current I(t).

Signals in proportion to alternating current I(t) can be acquired from the integral of output voltage signal V(t) of the closed Rogowski coil, which is the theory for the closed Rogowski coil to measure alternating current.
I(t)=K·∫V(t)dt(4)

As the closed Rogowski coil has high accuracy for current measurement and big bandwidth for measuring signal, it achieves the measurement by electric isolation at low cost, and its current withstanding capacity is almost infinite. The closed Rogowski coil is used in accurate current measurement of current-carrying conductor with permanent position, which has application in fields such as relay protection, etc.

During the current measurement conducted by the closed Rogowski coil100, the ring winding110picks up not only the magnetic variation of alternating current I(t) to be measured, but also other AC interfering magnetic fields in the space. For example, when the AC interfering magnetic field vertical to the page direction inFIG. 1occurs, voltage signal will be generated between the starting point130and ending point120of the ring winding110.

In order to reduce the influence on the measurement by the closed Rogowski coil100from the external magnetic field, besides the ring winding110of the closed Rogowski coil100, a cycle of return wire turn115will be wound between the ending point120and signal output end125of the ring winding110along the circle centered in center of the ring winding110. Thus, when the AC interfering magnetic field vertical to page direction inFIG. 1occurs, the voltage signal will be generated between the starting point120and ending point125of the return wire turn115by the AC interfering magnetic field. The voltage signal and the voltage signal between the starting point130and ending point120of the ring winding110are approximately equal in size and opposite in polarity with signal superposition result of approximately zero. Therefore, when the AC interfering magnetic field vertical to the page direction inFIG. 1occurs, almost no interfering voltage signal will be generated between the output ends125and130of the closed Rogowski coil100.

The traditional closed winding Rogowski coil, shown inFIG. 2, is formed through the winding on framework made of the circular non-magnetic conducting material, including the ring winding and the return wire turn. During the winding, the ring winding is wound after a cycle of return wire turn is placed in the center of the circular framework. The voltage signal generated by the external interfering magnetic field on ring winding of the closed Rogowski coil is approximately equal in size to the voltage signal generated on return wire turn but is opposite in polarity. Therefore, with signal superposition resulting in approximately zero, it reduces the influence of external magnetic field on measurement conducted by the closed Rogowski coil.

As the winding of the traditional closed winding Rogowski coil is generally completed by manual work or winding machine, it is hard to achieve uniform winding coil or equal cross section of each coil turn. The traditional closed winding Rogowski coil has the disadvantage of easy disconnection, large capacitance increase error, etc., so the parameter consistency during the industrial production is hard to be guaranteed. As a result, the characteristics of Rogowski coil during current measurement are affected.

A new type of closed Rogowski coil, called closed PCB Rogowski coil for short, is made from PCB to overcome the disadvantages of traditional closed Rogowski coil. See the circular closed PCB Rogowski coils305and310inFIG. 3. The closed PCB Rogowski coil is adopted with computer aided design (CAD), which means the printed wire (hereafter called wiring) is uniformly arranged on the PCB. See closed PCB Rogowski coil305inFIG. 3. A cycle of wire turn on the ring winding of closed PCB Rogowski coil305is composed of wiring315on the top layer (the top layer of PCB is the PCB surface which faces the reader, and the bottom layer is in opposite direction of the top layer), with plated through hole (hereafter called through hole for short)320connecting with the top layer and bottom layer and the wiring325on the bottom layer. Each wire turn cycle of the closed PCB Rogowski coil305is in radius direction from the center of circular PCB and is uniformly arranged along the circle with the section of the wire turn vertical to PCB.

As better digital processing technology being adopted for the PCB, the equality of section area on each wire turn cycle of the closed PCB Rogowski coil is ensured in the technological aspect. The produced closed PCB Rogowski coil not only overcomes the disadvantages of traditional closed Rogowski coil, but also enjoys optimized sensitivity, measurement accuracy and performance stability as compared to the traditional coil wound by copper wire. The production of closed PCB Rogowski coil is convenient and rapid, because it only needs to draw the wiring diagram on the computer. The closed PCB Rogowski coil is produced by numerical control machine tool to avoid the tedious process of winding, which shortens the coil processing cycle and improves the production efficiency. The variance of the closed PCB Rogowski parameter is small during mass production, and therefore, the performance parameters of coils from the same production batch are basically the same.

When the closed PCB Rogowski coil305is used for current measurement, besides the magnetic variation of alternating current I(t) to be measured, the ring winding also picks up other AC interfering magnetic fields in the space. For example, when the AC interfering magnetic field vertical to page direction inFIG. 3occurs, interfering voltage signal is generated between the output ends345and350of the closed PCB Rogowski coil305. In order to reduce the influence on measurement of closed PCB Rogowski coil305caused by the external magnetic field, the two series-connected PCBs on the closed PCB Rogowski coil can be adopted to form a combined PCB closed Rogowski coil.FIG. 3shows the series connection of closed PCB Rogowski coil305and closed PCB Rogowski coil310, which forms the combined PCB closed Rogowski coil300.

The wirings of closed PCB Rogowski coil310and closed PCB Rogowski coil305are arranged in a mirror image method with the wiring of ring winding in opposite direction. A wire turn cycle of the closed PCB Rogowski coil310is composed of wiring330on the bottom layer, the through hole335and wiring340on the top layer. The wire turn cycle of corresponding closed PCB Rogowski coil305is composed of wiring315on the top layer, the through hole320and wiring325on the bottom layer. Wiring330on the bottom layer and wiring315on the top layer are pairs, same as through hole335and through hole320, same as the wiring340on the top layer and wiring325on the bottom layer. These pairs are identical in position. It is the same with other wire turn cycles.

During the formation of combined PCB closed Rogowski coil300, the closed PCB Rogowski coil305and closed PCB Rogowski coil310are stacked up on the upper and lower layers. The output ends345and350of the closed PCB Rogowski coil305are in the same position completely with the output ends355and360of the closed PCB Rogowski coil310. Output end350of the closed PCB Rogowski coil305is connected with the output end360of the closed PCB Rogowski coil310to achieve the series connection of closed PCB Rogowski coil305and closed PCB Rogowski coil310. Output end365of the combined PCB closed Rogowski coil300is connected with the output end345of closed Rogowski coil305, and the output end370of combined PCB closed Rogowski coil300is connected with the output end355of the closed Rogowski coil310.

When the AC interfering magnetic field vertical to page direction inFIG. 3occurs, the interfering voltage signal generated between output ends345and350of the closed PCB Rogowski coil305and the interfering voltage signal generated between the output ends355and360of the closed PCB Rogowski coil310are approximately equal in size and opposite in polarity. Under the circumstance of the series connection of closed PCB Rogowski coil305and closed PCB Rogowski coil310, the superposition of the two interfering signals is approximately zero. Therefore, when the AC interfering magnetic field vertical to page direction inFIG. 1occurs, almost no interfering voltage signal will be generated between the output ends365and370of the combined PCB closed Rogowski coil300.

Although the distance of the two closed PCB Rogowski coils used in the handling method is very close, the interference of the two coils caused by the external magnetic field cannot be in full coherence and cannot be offset completely. Further, the two closed Rogowski coils can be designed on single PCB to achieve the interference reduction of external magnetic field more effectively through the series connection of the two designed closed PCB Rogowski coils.FIG. 4AandFIG. 4Bshow the closed PCB Rogowski coil formed by the series connection of two groups of coils in opposite wiring direction on single PCB (refer to HIGH PRECISION ROGOWSKI COIL, U.S. Pat. No. 6,313,623 Nov. 6, 2001).FIG. 4Ashows two groups of series-connected closed PCB Rogowski coils with opposite winding directions, whose wires are arranged on single PCB in a stagger way, andFIG. 4Bshows two groups of series-connected closed PCB Rogowski coils with opposite winding directions, whose wires are arranged on single PCB in an interdigital way.

FIG. 4AandFIG. 4Bshow a scheme of the closed PCB Rogowski coil formed by the series connection of two groups of coils in opposite wiring direction on single PCB, although by which the interference of external magnetic field can be reduced more effectively, the two coils designed like this still fail to be the same completely, so the influence from the interference of external magnetic field cannot be removed well.

The opened Rogowski coil is composed of coils in two halves. When the opened Rogowski coil is used for current measurement of the alternating current I(t) to be measured in the current-carrying conductor, firstly the two halves of coils of the opened Rogowski coil are required to be opened to surround the current-carrying conductor, and then two halves of coils of the opened Rogowski coil are required to be closed to place the current-carrying conductor in center of the opened Rogowski coil after being closed. Current-carrying conductor is made to pass through the center of opened Rogowski coil vertically to ensure measurement accuracy with the centers of the current-carrying conductor and opened Rogowski coil in superposition. The current-carrying conductor is surrounded by the opened Rogowski coil. When the alternating current I(t) to be measured flows through the current-carrying conductor, it generates an AC magnetic field around the current-carrying conductor, and the magnetic lines are approximated as the circle centered in center of the current-carrying conductor.

The opened Rogowski coil also has the above-mentioned disadvantages of closed Rogowski coil that the two coils fail to be the same completely, so the influence from the interference of external magnetic field cannot be removed well.

Therefore, it is necessary to provide a more accordant PCB Rogowski coil with two groups of series-connected coils in opposite winding direction, capable of further reducing the influence on measurement caused by the external magnetic field and improving the capacity of interference resistance of PCB Rogowski coil.

SUMMARY OF THE DISCLOSURE

The disclosure is aimed at providing a PCB Rogowski coil for being better to remove the influence from the interference of external magnetic field, so as to improve the capability of resisting external interference of the Rogowski coil.

The purpose of the disclosure is realized by the following technical scheme:

A PCB Rogowski coil comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, each of which includes multiple cycles of wire turns, furthermore:

One cycle of wire turn on the first coil includes a first incoming line, a first winding line and a first outgoing line, wherein the first winding lines of various cycles of wire turns on the first coil are parallel with each other and respectively arranged on the upper and lower surfaces of a PCB. The first incoming line, passing through a first through hole on the PCB, is connected with the first winding line. Then the first winding line, passing through a second through hole, is connected with the first outgoing line. Finally, the first outgoing line is also connected with the first incoming line of the lower cycle of wire turn on the first coil;

One cycle of wire turn on the second coil includes a second incoming line, a second winding line and a second outgoing line, wherein the second winding lines of various cycles of wire turns on the second coil are parallel with each other and respectively arranged on the upper and lower surfaces of a PCB. The second incoming line is connected with the second winding line. Then the second winding line, passing through a third through hole on the PCB, is led out from a fourth through hole and connected with the second outgoing line. Finally, the second outgoing line is also connected with the second incoming line of the lower cycle of wire turn on the second coil;

The first through hole is adjacent with the fourth through hole, the second through hole is adjacent with the third through hole, and the distance between the first winding line and the second winding line is less than that between two adjacent cycles of wire turns.

According to the technical scheme provided by the disclosure, the embodiment in the disclosure provides two groups of series-connected PCB Rogowski coils, which are more coincident and featured with opposite winding directions, capable of further reducing the influence of external magnetic field on the measurement and improving the capability of the Rogowski coil for resisting interference of external magnetic field.

DETAILED DESCRIPTION OF THE DISCLOSURE

Below in connection with the accompanying figures of the present disclosure embodiment, the present disclosure will be apparent in the technical implementation of the disclosure. The described embodiments are only part of the present disclosure, but not all. The described embodiments of the present disclosure, and all other embodiments perceived by those of ordinary skill in creativity, all belong to the scope of the present disclosure.

Below with references to the figures, the present disclosure is further described in detail.

The embodiment of the disclosure provides a PCB Rogowski coil, comprising two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, each of which includes multiple cycles of wire turns, furthermore:

One cycle of wire turn on the first coil includes a first incoming line, a first winding line and a first outgoing line, wherein the first winding lines of various cycles of wire turns on the first coil are parallel with each other and respectively arranged on the upper and lower surfaces of a PCB; the first incoming line, passing through a first through hole on the PCB, is connected with the first winding line, the first winding line, passing through a second through hole, is connected with the first outgoing line, and the first outgoing line is also connected with the first incoming line of the lower cycle of wire turn on the first coil;

One cycle of wire turn on the second coil includes a second incoming line, a second winding line and a second outgoing line, wherein the second winding lines of various cycles of wire turns on the second coil are parallel with each other and respectively arranged on the upper and lower surfaces of a PCB; the second incoming line is connected with the second winding line, the second winding line, passing through a third through hole on the PCB, is led out from a fourth through hole and connected with the second outgoing line, and the second outgoing line is also connected with the second incoming line of the lower cycle of wire turn on the second coil;

The first through hole is adjacent with the fourth through hole, the second through hole is adjacent with the third through hole, and the distance between the first winding line and the second winding line is less than that between two adjacent cycles of wire turns.

As multiple optional modes, the first coil and the second coil are arranged on single PCB to form a closed Rogowski coil with single PCB; or, they are arranged on multiple laminated PCBs to form an opened Rogowski coil with two PCBs; or they are arranged on they are arranged on two PCBs to form an opened Rogowski coil with two PCBs; or they are arranged on multiple PCB to form an opened Rogowski coils with multiple PCBs, wherein

In the closed Rogowski coil with multiple PCBs, multiple PCBs are laminated; furthermore, multiple cycles of wire turns on the first and second coils are respectively wound on each one of multiple PCBs, and the PCBs with multiple cycles of wire turns are orderly connected through the external access points on the PCBs;

In the opened Rogowski coil with two PCBs, two PCBs are designed to semicircular annular PCBs, multiple cycles of wire turns of the first and second coils are wound on the two PCBs, respectively; two PCBs with multiple cycles of wire turns are respectively provided with two external access points, two PCBs are connected through respective external access point, and the other two external access points of two PCBs are taken as the respective signal output ends of two PCBs, respectively;

In the opened Rogowski coil with multiple PCBs, multiple PCBs are laminated to form two groups of semicircular annular PCBs, multiple cycles of wire turns of the first and second coils are wound on the two groups of PCBs, respectively; in the same group of semicircular annular PCBs, the semicircular annular PCB with multiple cycles of wire turns are connected by the respective external access point, and one of the other two external access points on the semicircular annular PCB is taken as the connecting point in the other group of semicircular annular PCBs, and the other one is taken as the signal output end of the group of semicircular annular PCBs;

The first one of multiple optional modes above is: closed Rogowski coil with single PCB:

(a) A composition unit is composed of a cycle of wire turn on the first coil and a cycle of adjacent wire turn on the second coil, two cycles of wire turns in the composition unit are adjacent closely, and multiple identical composition units are connected in series;

And/or, (b) the first incoming line and the first outgoing line of the first coil in each composition unit are respectively connected with the wire turns of the first coils on an upper composition unit and a lower composition unit, the first winding line is composed of wirings on the top layer and bottom layer, a first through hole and a second through hole between the top layer and the bottom layer by surrounding, the second incoming line and the second outgoing line of each composition unit are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the second winding line is composed of wirings on the top layer and bottom layer, a third through hole and a fourth through hole between the top layer and the bottom layer by surrounding.

That two cycles of wire turns in the composition unit are adjacent closely can be understood as: the minimum space between two cycles of wire turns in the composition unit is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

Further, the closed Rogowski coil with single PCB also can be described as follows:

(a) Two signal output ends are provided, i.e. a first signal output end and a second signal output end, wherein that connected with the first signal output end is the first incoming line at the first cycle of wire turn on the first coil, that connected with the second signal output end is the second incoming line at the second cycle of wire turn on the second coil, the first outgoing line at the last cycle of wire turn on the first coil is connected with the second outgoing line at the last cycle of wire turn on the second coil, and serial connection between the first coil and the second coil of the closed Rogowski coil with single PCB is realized;

And/or, (b) the section composed of the first winding lines at the various cycles of wire turns on the first coil by surrounding is located on a cross section of PCB, and the first winding lines at the various cycles of wire turns on the first coil are overlapped in the direction vertical to the surface of PCB; the section composed of the second winding lines at the various cycles of wire turns on the second coil by surrounding is located on a cross section of PCB, and the second winding lines at the various cycles of wire turns on the second coil are overlapped in the direction vertical to the surface of PCB;

And/or, (c) the centers of all the composition units are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at the wire turns on the first coil of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at the wire turns on the first coil is approximately vertical to the normal direction of the magnetic line passing through the section center of the winding line; the direction of the section surrounded by the winding lines at the wire turns on the second coil of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at the wire turns on the second coil is approximately vertical to the normal direction of the magnetic line passing through the section center of the winding line.

The technical scheme provided by the embodiment in the disclosure provides two groups of series-connected PCB Rogowski coils, which are more coincident and featured with opposite winding directions, capable of further reducing the influence of external magnetic field on the measurement and improving the capability of the Rogowski coil for resisting interference of external magnetic field.

As the total magnetic flux picked up by the ring winding of closed PCB Rogowski coil is in direct proportion to the sectional area, the larger the sectional area of ring winding is, the larger the variation of the total magnetic flux will be. For the same current to be measured, the stronger the output signals the PCB Rogowski coil is, and the higher the detection sensitivity of the closed PCB Rogowski coil will be. As the sectional area of the ring winding of the closed PCB Rogowski coil is in direct proportion to the thickness of the PCB, the thicker the latter is, the larger the former will be, and the higher the detection sensitivity of the closed PCB Rogowski coil will be. Hence, a thicker PCB can be adopted to improve the detection sensitivity of the closed PCB Rogowski coil: However, the thickness of the PCB can't be increased definitely as the processing technology. The processing cost will largely increase with the increase of the thickness of the PCB. The closed Rogowski coil with single PCB at a certain thickness will cost much higher than the PCB Rogowski coil with the same thickness composed of multiple thin PCBs. Whereas it's better to produce the closed Rogowski coils with multiple PCBs composed of multiple thin PCBs than the closed Rogowski coil with single PCB at the same thickness.

Thus, the second one of multiple optional modes above is: closed Rogowski coil with multiple PCBs:

(a) Two signal output ends are provided, i.e. a first signal output end and a second signal output end, wherein in N laminated PCBs, the PCB with the first signal output end and the second signal output end is the 1stPCB, the PCB adjacent with the 1stboard is the 2ndPCB, till the NthPCB is present;

And/or, (b) four external access points are set on the 1stPCB to the (N−1)thPCB, i.e. the first external access point, the second external access point, the third external access point and the fourth external access point, wherein the first external access point and the third external access point are the starting point and ending point of the first coil from the 1stPCB to the (N−1)thPCB, the second external access point and the fourth external access point are the starting point and ending point of the second coil from the 1stPCB to the (N−1)thPCB; the NthPCB is provided with two external access points, i.e. the first external access point and the second external access point, wherein the first external access point is the starting point of the first coil on the NthPCB, and the second external access point is the starting point of the second coil on the NthPCB;

And/or, (c) the first external access point on the 1stPCB is the first signal output end, and the second external access point on the 1stPCB is the second signal output end;

And/or, (d) the third external access point of an upper PCB in the adjacent laminated PCBs is connected with the first external access point on a lower PCB to realize series connection between the first coil on the upper PCB and the first coil on the lower PCB to form a complete first coil; the fourth external access point of an upper PCB in the adjacent laminated PCBs is connected with the second external access point on a lower PCB to realize series connection between the second coil on the upper PCB and the second coil on the lower PCB to form a complete second coil; and the first coil and second coil are directly connected in series on the NthPCB.

Further, multiple closed PCB Rogowski coil also can be described as follows:

(a) A composition unit is composed of a cycle of wire turn on the first coil and a cycle of adjacent wire turn on the second coil in each PCB, multiple identical composition units are connected in series, and two cycles of wire turns in the composition unit are adjacent closely;

And/or, (b) the first incoming line and the first outgoing line of the first coil in each composition unit are respectively connected with the wire turns of the first coils on an upper composition unit and a lower composition unit, the first winding line is composed of wirings on the top layer and bottom layer, a first through hole and a second through hole between the top layer and the bottom layer by surrounding, the second incoming line and the second outgoing line of each composition unit are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the second winding line is composed of wirings on the top layer and bottom layer, a third through hole and a fourth through hole between the top layer and the bottom layer by surrounding.

And/or, (c) the first incoming line at one cycle of wire turn on the first coil of the first composition unit from the 1stPCB to the NthPCB is connected with the first external access point from the 1stPCB to the NthPCB, the second incoming line at one cycle of wire turn on the second coil of the first composition unit from the 1stPCB to the NthPCB is connected with the second external access point from the 1stPCB to the NthPCB, the first outgoing line at one cycle of wire turn on the first coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the third external access point from the 1stPCB to the (N−1)thPCB, the second outgoing line at one cycle of wire turn on the second coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the fourth external access point from the 1stPCB to the (N−1)thPCB, and the first outgoing line at one cycle of wire turn on the first coil of the last composition unit on the NthPCB is directly connected with the second outgoing line at one cycle of wire turn on the second coil of the last composition unit on the NthPCB, so as to realize the series connection of the first coil and second coil on the NthPCB;

And/or, (d) the section composed of the winding lines at two cycles of wire turns of each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB;

And/or, (e) the centers of the composition units on each PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line.

That two cycles of wire turns in the composition unit are adjacent closely can be understood as: the minimum space between two cycles of wire turns in the composition unit is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

The technical scheme provided by the embodiment in the disclosure provides two groups of series-connected PCB Rogowski coils, which are more coincident and featured with opposite winding directions, capable of further reducing the influence of external magnetic field on the measurement and improving the capability of the Rogowski coil for resisting interference of external magnetic field.

The third one of multiple optional modes above is: opened Rogowski coil with two PCBs:

(a) Two external access points are set each PCB, i.e. the first external access point and the second external access point, wherein the first external access point on each PCB is the starting point of the first coil on the PCB, and the second external access point on the PCB is the ending point of the second coil on the PCB;

And/or, (b) two connection modes are provided for two PCBs: the first external access points of two PCBs are connected directly, the second external access points of two PCBs are taken as two signal output ends of the opened Rogowski coil with two PCBs, i.e. the first signal output end and the second signal output end; or, the second external access points of two PCBs are connected directly, the first access points of two PCBs are taken as two signal output ends of the opened Rogowski coil with two PCBs, i.e. the first signal output end and the second signal output end.

Further, the opened Rogowski coil with two PCBs also can be described as follows:

(a) A composition unit is composed of a cycle of wire turn on the first coil and a cycle of adjacent wire turn on the second coil in each of the opened Rogowski coil with two PCBs, multiple identical composition units are connected in series, and two cycles of wire turns in the composition unit are adjacent closely;

And/or, (b) the first incoming line and the first outgoing line of the first coil in each composition unit are respectively connected with the wire turns of the first coils on an upper composition unit and a lower composition unit, the first winding line is composed of wirings on the top layer and bottom layer, a first through hole and a second through hole between the top layer and the bottom layer by surrounding, the second incoming line and the second outgoing line of each composition unit are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the second winding line is composed of wirings on the top layer and bottom layer, a third through hole and a fourth through hole between the top layer and the bottom layer by surrounding.

And/or, (c) the PCB with the first signal output end is the 1stPCB, the PCB with the second signal output end is the 2ndPCB, the first incoming line at one cycle of wire turn on the first coil of the first composition unit on the 1stPCB is connected with the first external access point of the 1stPCB, the second incoming line at one cycle of wire turn on the second coil of the first composition unit on the 1stPCB is connected with the second external access point of the 1stPCB, the first incoming line at one cycle of wire turn on the first coil of the first composition unit on the 2ndPCB is connected with the first external access point of the 2ndPCB, and the second incoming line at one cycle of wire turn on the second coil of the first composition unit on the 2ndPCB is connected with the second external access point of the 2ndPCB;

And/or, (d) the first outgoing line at one cycle of wire turn on the first coil of the last composition unit on the 1stPCB is directly connected with the second outgoing line at one cycle of wire turn on the second coil of the last composition unit on the 1stPCB to realize series connection between the first coil and the second coil on the 1stPCB, and the first outgoing line at one cycle of wire turn on the first coil of the last composition unit on the 2ndPCB is directly connected with the second outgoing line at one cycle of wire turn on the second coil of the last composition unit on the 2ndPCB to realize series connection between the first coil and the second coil on the 2ndPCB;

And/or, (e) the section composed of the winding lines at two cycles of wire turns of each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB;

And/or, (f) the centers of the composition units on each PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line.

That two cycles of wire turns in the composition unit are adjacent closely can be understood as: the minimum space between two cycles of wire turns in the composition unit is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

The technical scheme provided by the embodiment in the disclosure provides two groups of series-connected PCB Rogowski coils, which are more coincident and featured with opposite winding directions, capable of further reducing the influence of external magnetic field on the measurement and improving the capability of the Rogowski coil for resisting interference of external magnetic field.

As the total magnetic flux picked up by the ring winding of the PCB Rogowski coil is in direct proportion to the sectional area, the larger the sectional area of ring winding is, the larger the variation of the total magnetic flux will be. For the same current to be measured, the stronger the output signals output from the PCB Rogowski coil is, and the higher the detection sensitivity of the PCB Rogowski coil will be. As the sectional area of the ring winding of the PCB Rogowski coil is in direct proportion to the thickness of the PCB, the thicker the latter is, the larger the former will be, and the higher the detection sensitivity of the PCB Rogowski coil will be. Hence, a thicker PCB can be adopted to improve the detection sensitivity of the PCB Rogowski coil. However, the thickness of the PCB can't be increased definitely as the processing technology. The processing cost will largely increase with the increase of the thickness of the PCB. The Rogowski coil with single PCB at a certain thickness will cost much higher than the PCB Rogowski coil with the same thickness composed of multiple thin PCBs. Whereas it's better to produce the Rogowski coils with multiple PCBs composed of multiple thin PCBs than that with a single PCB.

Thus, the fourth one of multiple optional modes above is: opened Rogowski coils with multiple PCBs:

(a) The same group of semicircular annular PCBs are composed of N PCBs by alternating, each group of semicircular annular PCBs is provided with two signal output ends, i.e. the first signal output end and the second signal output end, wherein the PCB with first signal output end and the second signal output end is the 1stPCB, and the PCB adjacent with the 1stPCB is the 2ndPCB, till the NthPCB is present;

And/or, (b) four external access points are set on the 1stPCB to the (N−1)thPCB in each group of semicircular annular PCBs, i.e. the first external access point, the second external access point, the third external access point and the fourth external access point, wherein the first external access point and the third external access point are the starting point and ending point of the first coil from the 1stPCB to the (N−1)thPCB, the second external access point and the fourth external access point are the starting point and ending point of the second coil from the 1stPCB to the (N−1)thPCB; the NthPCB in each group of semicircular annular PCBs is provided with two external access points, i.e. the first external access point and the second external access point, wherein the first external access point is the starting point of the first coil on the NthPCB, and the second external access point is the starting point of the second coil on the NthPCB;

And/or, (c) the first external access point on the 1stPCB in each group of semicircular annular PCBs is the first signal output end, the second external access point on the 1stPCB is the second signal output end, the third external access point of the upper PCB in the adjacent laminated PCBs in each group of semicircular annular PCBs is connected with the first external access point on the lower PCB to realize the series connection between the first coil on the upper PCB and the first coil on the lower PCB to form the complete first coil; the fourth access point of the upper PCB in the adjacent laminated PCBs in each group of semicircular annular PCBs is connected with the second external access point on the lower PCB to realize the series connection between the second coil on the upper PCB and the second coil on the lower PCB to form the complete second coil; the first coil and second coil on each half of PCB Rogowski coil are directly connected in series on the NthPCB to form a group of semicircular annular PCBs;

And/or, (d) the first signal output ends on two groups of semicircular annular PCBs are connected directly, and the second signal output ends thereon are taken as two signal output ends of the opened Rogowski coil with multiple PCBs, i.e. the first signal output end and the second signal output end; or the second signal output ends on two groups of semicircular annular PCBs are connected directly, and the first signal output ends thereon are taken as two signal output ends of, the opened Rogowski coil with multiple PCBs, i.e. the first signal output end and the second signal output end.

Further, opened Rogowski coil with multiple PCBs also can be described as follows:

(a) A composition unit is composed of a cycle of wire turn on the first coil and a cycle of adjacent wire turn on the second coil in each PCB of the opened Rogowski coil with multiple PCBs, multiple identical composition units are connected in series, and two cycles of wire turns in the composition unit are adjacent closely;

And/or, (b) the first incoming line and the first outgoing line of the first coil in each composition unit are respectively connected with the wire turns of the first coils on an upper composition unit and a lower composition unit, the first winding line is composed of wirings on the top layer and bottom layer, a first through hole and a second through hole between the top layer and the bottom layer by surrounding, the second incoming line and the second outgoing line of each composition unit are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the second winding line is composed of wirings on the top layer and bottom layer, a third through hole and a fourth through hole between the top layer and the bottom layer by surrounding.

And/or, (c) the first incoming line at one cycle of wire turn on the first coil of the first composition unit from the 1stPCB to the NthPCB is connected with the first external access point from the 1stPCB to the NthPCB, the second incoming line at one cycle of wire turn on the second coil of the first composition unit from the 1stPCB to the NthPCB is connected with the second external access point from the 1stPCB to the NthPCB, the first outgoing line at one cycle of wire turn on the first coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the third external access point from the 1stPCB to the (N−1)thPCB, the second outgoing line at one cycle of wire turn on the second coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the fourth external access point from the 1stPCB to the (N−1)thPCB, and the first outgoing line at one cycle of wire turn on the first coil of the last composition unit on the NthPCB is directly connected with the second outgoing line at one cycle of wire turn on the second coil of, the last composition unit on the NthPCB, so as to realize the series connection of the first coil and second coil on the NthPCB;

And/or, (d) the section composed of the winding lines at two cycles of wire turns of each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths on the top layer and bottom layer of the winding lines are overlapped in the direction vertical to the surface of PCB;

And/or, (e) the centers of each composition unit are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line.

That two cycles of wire turns in the composition unit are adjacent closely can be understood as: the minimum space between two cycles of wire turns in the composition unit is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

The technical scheme provided by the embodiment in the disclosure provides two groups of series-connected PCB Rogowski coils, which are more coincident and featured with opposite winding directions, capable of further reducing the influence of external magnetic field on the measurement and improving the capability of the PCB Rogowski coil for resisting interference of external magnetic field.

For easy understanding, specific implementation mode for different types of Rogowski coils is described in detail below.

(I) Closed Rogowski Coil with Single PCB

Closed Rogowski coil with single PCB capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, both of which are located on single PCB and are connected in series to form a closed Rogowski coil with single PCB.

The closed Rogowski coil with single PCB capable of resisting interference of external magnetic field is specifically composed of multiple identical composition units in series connection, each of which comprises one cycle of wire turn on the first coil and one cycle of wire turn on the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

One cycle of wire turn on the first coil of each composition unit on the closed Rogowski coil with single PCB comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle. One cycle of wire turn on the first coil of each composition unit on the closed Rogowski coil with single PCB comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding.

The closed Rogowski coil with single PCB capable of resisting interference of external magnetic field is provided with two signal output ends, i.e. the first signal output end and the second signal output end, wherein that connected with the first signal output end is the incoming line of the wire turn on the first coil of the first composition unit, and that connected with the second signal output end is the incoming line of the wire turn on the second coil of the first composition unit. That adjacent with the first composition unit is the second composition unit, the rest can be done in the same manner till the last composition unit is present. The outgoing line of the wire turn on the first coil of the last composition unit is directly connected with the outgoing line of the wire turn on the second coil of the last composition to realize the series connection between the first coil and the second coil of the closed Rogowski coil with single PCB.

For the closed Rogowski coil with single PCB capable of resisting interference of external magnetic field, the section composed of the wire turns of the first coil on each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB. The section composed of the winding lines at the wire turn of the second coil on each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the closed Rogowski coil with single PCB capable of resisting interference of external magnetic field, the centers of all the composition units are uniformly distributed on the magnetic line of magnetic field for generating current to be measured. The direction of section composed of the winding lines on the wire turns of the first coils on all the composition units by surrounding is approximate to the normal direction of the magnetic line passing through the section center of the winding line, and the section composed of the winding lines on the wire turns of the first coils is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line (namely strength direction of magnetic field). The direction of section composed of the winding lines on the wire turns of the second coils on all the composition units by surrounding is approximate to the normal direction of the magnetic line passing through the section center of the winding line, and the section composed of the winding lines on the wire turns of the second coils is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line (namely strength direction of magnetic field).

In the closed Rogowski coil with single PCB, the PCB is a dual-sided PCB, wherein the first coil and the second coil are located on the upper and lower surfaces of the PCB, so the closed Rogowski coil with single PCB can be called a closed Rogowski coil with single dual-sided PCB.

Closed Rogowski coil with single dual-sided PCB capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, both of which are located on single dual-sided PCB and are connected in series to form a closed Rogowski coil with single dual-sided PCB.

The closed Rogowski coil with single dual-sided PCB capable of resisting interference of external magnetic field is specifically composed of multiple identical composition units in series connection, each of which comprises one cycle of wire turn on the first coil and one cycle of wire turn on the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

One cycle of wire turn on the first coil of each composition unit comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. One cycle of wire turn on the second coil of each composition unit on closed Rogowski coil with single dual-sided PCB comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding.

The closed Rogowski coil with single dual-sided PCB capable of resisting interference of external magnetic field is provided with two signal output ends, i.e. the first signal output end and the second signal output end, wherein that connected with the first signal output end is the incoming line of the wire turn on the first coil of the first composition unit, and that connected with the second signal output end is the incoming line of the wire turn on the second coil of the first composition unit. That adjacent with the first composition unit is the second composition unit, the rest can be done in the same manner till the last composition unit is present. The outgoing line of the wire turn on the first coil of the last composition unit is directly connected with the outgoing line of the wire turn on the second coil of the last composition to realize the series connection between the first coil and the second coil of closed Rogowski coil with single dual-sided PCB.

For the closed Rogowski coil with single dual-sided PCB capable of resisting interference of external magnetic field, the section composed of the wire turns of the first coil on each composition unit by surrounding is vertical to the surface of dual-sided PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of dual-sided PCB. The section composed of the winding lines at the wire turn of the second coil on each composition unit by surrounding is vertical to the surface of dual-sided PCB, the section composed of the winding lines by surrounding is located on the cross section of dual-sided PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of dual-sided PCB.

For the closed Rogowski coil with single dual-sided PCB capable of resisting interference of external magnetic field, the centers of all the composition units are uniformly distributed on the magnetic line of magnetic field for generating current to be measured. The direction of section composed of the winding lines on the wire turns of the first coils on all the composition units by surrounding is approximate to the normal direction of the magnetic line passing through the section center of the winding line, and the section composed of the winding lines on the wire turns of the first coils is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line (namely strength direction of magnetic field). The direction of section composed of the winding lines on the wire turns of the second coils on all the composition units by surrounding is approximate to the normal direction of the magnetic line passing through the section center of the winding line, and the section composed of the winding lines on the wire turns of the second coils is approximately vertical to the tangential direction of the magnetic line passing through the section center of the winding line (namely strength direction of magnetic field).

FIG. 5shows a specific embodiment of the disclosure, or a closed Rogowski coil with single dual-sided PCB500capable of resisting interference of external magnetic field, which is suitable for measuring the current flowing on a current-carrying conductor105vertically passing through the center of closed PCB Rogowski coil500, and the magnetic line of AC magnetic field generated by the current is a circle of taking the center of closed PCB Rogowski coil500as the center of a circle.FIG. 5Ashows a laminating layer on the top layer and bottom layer of the closed Rogowski coil with single dual-sided PCB,FIG. 5Bshows a top layer of the closed Rogowski coil with single dual-sided PCB, andFIG. 5Cshows a bottom layer of the closed Rogowski coil with single dual-sided PCB.

The closed Rogowski coil with single dual-sided PCB500comprises two groups of coils501and502with opposite winding directions, Wherein the coil501is connected with the coil502in series to form a closed PCB Rogowski coil500. The closed Rogowski coil with single dual-sided PCB500is composed of multiple identical composition units in series connection, andFIG. 5Ashows a composition unit503. As shown inFIG. 5A,FIG. 5BandFIG. 5C, the center of composition unit503and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor105, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit comprises one cycle of wire turn of two groups of coils with opposite winding directions. The composition unit503comprises a cycle of wire turn504on the coil501and a cycle of wire turn505on the coil502, and the two cycles of wire turns are adjacent closely.FIG. 5Bshows a top layer part506of the wire turn504and a top layer part507of the wire turn505on the composition unit503. The top layer part506of the wire turn504is adjacent with the top layer part507of the wire turn506closely,FIG. 5Cshows a bottom layer part508of the wire turn504and a bottom layer part509of the wire turn505on the composition unit503. The bottom layer part508of the wire turn504is adjacent with the bottom layer part509of the wire turn506closely.

FIG. 6shows local details of the closed Rogowski coil with single dual-sided PCB500.FIG. 6Ashows a laminating layer on the local top layer and bottom layer of the closed Rogowski coil with single dual-sided PCB500,FIG. 6Bshows a local top layer of the closed Rogowski coil with single dual-sided PCB500, andFIG. 6Cshows a local bottom layer of the closed Rogowski coil with single dual-sided PCB500.

The laminating layer on the top layer and bottom layer of a composition unit600on the closed PCB Rogowski coil500, as shown inFIG. 6A, comprises a laminating layer part of a cycle of wire turn618on the coil620and a laminating layer part of a cycle of wire turn619on the other group of coil621with opposite winding direction. The laminating layer part of a cycle of wire turn618on the coil620comprises an incoming line601, a wiring line607, a through hole609, a through hole604and an outgoing line606. The laminating layer part of a cycle of wire turn619on the coil621comprises an incoming line602, a wiring line608, a through hole610, a through hole603and an outgoing line605.

The top layer of a composition unit600on the closed PCB Rogowski coil500, as shown inFIG. 6B, comprises a top layer part of a cycle of wire turn618on the coil620and a top layer part of a cycle of wire turn619on the other group of coil621with opposite winding direction. The top layer part of a cycle of wire turn618on the coil620comprises a through hole609, a wiring line616and a through hole604. The top layer part of a cycle of wire turn619on the coil621comprises an incoming line602, a wiring line617, a through hole610, a through hole603and an outgoing line605.

The bottom layer of a composition unit600on the closed PCB Rogowski coil500, as shown inFIG. 6C, comprises a bottom layer part of a cycle of wire turn618on the coil620and a bottom layer part of a cycle of wire turn619on the other group of coil621with opposite winding direction. The bottom layer part of a cycle of wire turn618on the coil620comprises an incoming line601, a wiring line614, a through hole609, a through hole604and an outgoing line606. The bottom layer part of a cycle of wire turn619on the coil621comprises a through hole610, a wiring line615and a through hole603.

As shown inFIG. 6A,FIG. 6BandFIG. 6C, the rectangular winding part of a cycle of wire turn618on the coil620of the closed PCB Rogowski coil500is composed of a wiring line616, a through hole609, a wiring line614and a through hole604, wherein the wiring line616on the top layer of the rectangular winding part and the wiring line614on the bottom layer are overlapped in the direction vertical to the surface of PCB. The rectangular winding part of a cycle of wire turn619on the other group of coil621with opposite winding direction is composed of a wiring line615, a through hole610, a wiring line617and a through hole603, wherein the wiring line615on the bottom layer of the rectangular winding part and the wiring line617on the top layer are overlapped in the direction vertical to the surface of PCB.

As shown inFIG. 6A,FIG. 6BandFIG. 6C, the rectangular winding section directions of a cycle of wire turn618and a cycle of wire turn619on the first composition unit600of the closed PCB Rogowski coil500are along the radial direction of the centers of closed PCB Rogowski coil500and winding section, or the magnetic line with the centers of various composition units on the closed PCB Rogowski coil500is in the normal direction in the center of the winding section.

As shown inFIG. 6A,FIG. 6BandFIG. 6C, the rectangular winding section directions of a cycle of wire turn618and a cycle of wire turn619on the first composition unit600of the closed PCB Rogowski coil500are vertical to the radial direction of the centers of closed PCB Rogowski coil500and winding section, or the magnetic line with the centers of various composition units on the closed PCB Rogowski coil500is in the tangential direction in the center of the winding section.

As shown inFIG. 6A,FIG. 6BandFIG. 6C, the first composition unit of the closed PCB Rogowski coil500is provided with an external access point611, which is connected with the incoming line of the first wire turn on the coil620of the first composition unit, and the first composition unit of the closed PCB Rogowski coil500is provided with an external access point612, which is connected with the incoming line of the first wire turn on the other group of coil621with opposite winding direction of the first composition unit. The external access points611and612are taken as two signal output ends of the closed PCB Rogowski coil500.

As shown inFIG. 6A,FIG. 6BandFIG. 6C, two outgoing lines between the through hole622of the coil620and the through hole623of the other group of coil621on the last composition unit613of the closed PCB Rogowski coil500are directly connected through a wiring line624to realize the series connection between two groups of coils620and621with opposite winding directions on the closed PCB Rogowski coil500.

(II) Closed Rogowski Coil with Multiple (N≥2) PCBs

The closed Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil.

The closed Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field is specifically composed of N PCBs by laminating. The closed Rogowski coil with multiple PCBs is provided with two signal output ends, i.e. the first signal output end and the second signal output end. The PCB with the first and second signal output ends is the 1stPCB, the PCB adjacent with the 1stPCB is the 2ndPCB, if N≥3, the rest can be done in the same manner, it is the 3rdPCB till the NthPCB is present.

Four external access points are set from the 1stPCB to the (N−1)thPCB, i.e. the first external access point, the second external access point, the third external access point and the fourth external access point, wherein the first external access point and the third external access point are the starting point and the ending point of the first coil from the 1stPCB to the (N−1)thPCB, respectively; and the second external access point and the fourth external access point are the starting point and the ending point of the second coil from the 1stPCB to the (N−1)thPCB, respectively. The NthPCB is provided with two external access points, i.e. the first external access point and the second external access point, wherein the first external access point is the starting point of the first coil on the NthPCB, and the second external access point is the starting point of the second coil on the NthPCB.

The first external access point on the 1stPCB is the first signal output end, and the second external access point on the 1stPCB is the second signal output end; The third external access point on the upper one of the adjacent and laminated PCBs is connected with the first external access point on the lower one to realize the series connection between the first coil part on the upper PCB and the first coil part on the lower PCB to form a complete first coil. The fourth external access point on the upper one of the adjacent and laminated PCBs is connected with the second external access point on the lower one to realize the series connection between the second coil part on the upper PCB and the second coil part on the lower PCB to form a complete second coil. The first and second coils are directly connected in series on the NthPCB to form the closed Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field.

Each PCB from the 1stPCB to the NthPCB is composed of multiple identical composition units in series connection, each of which comprises the cycles of wire turns of the first coil and the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm. One cycle of wire turn on the first coil of each composition unit on each PCB of the closed Rogowski coil with multiple PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. One cycle of wire turn on the second coil of each composition unit on each PCB of the closed Rogowski coil with multiple PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle.

The incoming line at one cycle of wire turn on the first coil of the first composition unit from the 1stPCB to the NthPCB is connected with the first external access point from the 1stPCB to the NthPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit from the 1stPCB to the NthPCB is connected with the second external access point from the 1stPCB to the NthPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the third external access point from the 1stPCB to the (N−1)thPCB, and the outgoing line at one cycle of wire turn on the second coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the fourth external access point from the 1stPCB to the (N−1)thPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the NthPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the NthPCB to realize the series connection between the first coil and the second coil on the NthPCB.

For the closed Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field, the section composed of two cycles of wire turns on each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the closed Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field, the centers of the composition units on each PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction (strength direction of the magnetic field) of the magnetic line passing through the section center of the winding line.

In the closed Rogowski coil with multiple PCBs, the PCB is a dual-sided PCB, wherein the first coil and the second coil are located on the upper and lower surfaces of the PCB, so the closed Rogowski coil with multiple PCBs can be called a closed Rogowski coil with multiple dual-sided PCBs.

The closed Rogowski coil with multiple dual-sided PCBs capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil.

The closed Rogowski coil with multiple dual-sided PCBs capable of resisting interference of external magnetic field is specifically composed of N dual-sided PCBs by laminating. The closed Rogowski coil with multiple dual-sided PCBs is provided with two signal output ends, i.e. the first signal output end and the second signal output end. The PCB with the first and second signal output ends is the 1stPCB, the PCB adjacent with the 1stPCB is the 2ndPCB, if the rest can be done in the same manner, it is the 3rdPCB till the NthPCB is present.

Four external access points are set from the 1stPCB to the (N−1)thPCB, i.e. the first external access point, the second external access point, the third external access point and the fourth external access point, wherein the first external access point and the third external access point are the starting point and the ending point of the first coil from the 1stPCB to the (N−1)thPCB, respectively; and the second external access point and the fourth external access point are the starting point and the ending point of the second coil from the 1stPCB to the (N−1)thPCB, respectively. The NthPCB is provided with two external access points, i.e. the first external access point and the second external access point, wherein the first external access point is the starting point of the first coil on the NthPCB, and the second external access point is the starting point of the second coil on the NthPCB.

The first external access point on the 1stPCB is the first signal output end, and the second external access point on the 1stPCB is the second signal output end; The third external access point on the upper one of the adjacent and laminated PCBs is connected with the first external access point on the lower one to realize the series connection between the first coil part on the upper PCB and the first coil part on the lower PCB to form a complete first coil. The fourth external access point on the upper one of the adjacent and laminated PCBs is connected with the second external access point on the lower one to realize the series connection between the second coil part on the upper PCB and the second coil part on the lower PCB to form a complete second coil. The first and second coils are directly connected in series on the NthPCB to form the closed Rogowski coil with multiple dual-sided PCBs capable of resisting interference of external magnetic field.

Each dual-sided PCB from the 1stPCB to the NthPCB is composed of multiple identical composition units in series connection, each of which comprises the cycles of wire turns of the first coil and the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm. One cycle of wire turn on the first coil of each composition unit on each dual-sided PCB of the closed Rogowski coil with multiple dual-sided PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. One cycle of wire turn on the second coil of each composition unit on each dual-sided PCB of the closed Rogowski coil with multiple dual-sided PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle.

The incoming line at one cycle of wire turn on the first coil of the first composition unit from the 1stPCB to the NthPCB is connected with the first external access point from the 1stPCB to the NthPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit from the 1stPCB to the NthPCB is connected with the second external access point from the 1stPCB to the NthPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the third external access point from the 1stPCB to the (N−1)thPCB, and the outgoing line at one cycle of wire turn on the second coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the fourth external access point from the 1stPCB to the (N−1)thPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the NthPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the NthPCB to realize the series connection between the first coil and the second coil on the NthPCB.

For the closed Rogowski coil with multiple dual-sided PCBs capable of resisting interference of external magnetic field, the section composed of two cycles of wire turns on each composition unit by surrounding is vertical to the surface of dual-sided PCB, the section composed of the winding lines by surrounding is located on the cross section of dual-sided PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the closed Rogowski coil with multiple dual-sided PCBs capable of resisting interference of external magnetic field, the centers of the composition units on each dual-sided PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction (strength direction of the magnetic field) of the magnetic line passing through the section center of the winding line.

FIG. 7shows dual-sided PCBs from the 1stPCB to the (N−1)thPCB in the closed Rogowski coil with N dual-sided PCBs in the embodiment of the disclosure,FIG. 7Ashows the laminating layer of the top layer and bottom layer of the dual-sided PCBs from the 1stPCB to the (N−1)thPCB in the closed Rogowski coil with N dual-sided PCBs,FIG. 7Bshows the top layers of the dual-sided PCBs from the 1stPCB to the (N−1)thPCB in the closed Rogowski coil with N dual-sided PCBs, andFIG. 7Cshows bottom layers of the dual-sided PCBs from the 1stPCB to the (N−1)thPCB in the closed Rogowski coil with N dual-sided PCBs.

The coil700on the dual-sided PCBs from the 1stPCB to the (N−1)thPCB in the closed Rogowski coil with N dual-sided PCBs comprises two groups of coils701and702with opposite winding directions, which represent one part of the first coil and second coil on the closed Rogowski coil with N dual-sided PCBs, respectively.

The coil700is provided with four external access points, i.e.703,704,705,706. The external access point703is taken as the starting point of the coil701, the external access point705is taken as the ending point of the coil701, the external access point704is taken as the starting point of the coil702, and the external access point706is taken as the ending point of the coil702.

The external access points703and704are also taken as the signal output ends of the closed Rogowski coil with N dual-sided PCBs at the same time. The external access point707is connected with the first coil part on the lower dual-sided PCB, and the external access point706is connected with the second coil part thereon.

The coil700is composed of multiple identical composition units in series connection, andFIG. 7Ashows a composition unit707. As shown inFIG. 7A,FIG. 7BandFIG. 7C, the center of composition unit707and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor105, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit comprises one cycle of wire turn of two groups of coils with opposite winding directions. The composition unit707comprises a cycle of wire turn708on the coil701and a cycle of wire turn709on the coil702, and the two cycles of wire turns are adjacent closely.FIG. 7Bshows a top layer part710of the wire turn708and a top layer part711of the wire turn709on the composition unit707. The top layer part710of the wire turn708is adjacent with the top layer part711of the wire turn709closely,FIG. 7Cshows a bottom layer part712of the wire turn708and a bottom layer part713of the wire turn709on the composition unit707. The bottom layer part712of the wire turn708is adjacent with the bottom layer part713of the wire turn709closely.

FIG. 8shows the Nthdual-sided PCB in the closed Rogowski coil with N dual-sided PCBs according to the specific embodiment of the disclosure,FIG. 8Ashows the laminating layer of the top layer and bottom layer of the Nthdual-sided PCB in the closed Rogowski coil with N dual-sided PCBs,FIG. 8Bshows the top layer of the Nthdual-sided PCB in the closed Rogowski coil with N dual-sided PCBs, andFIG. 8Cshows bottom layer of the Nthdual-sided PCB in the closed Rogowski coil with N dual-sided PCBs.

The coil800on the Nthdual-sided PCB in the closed Rogowski coil with N dual-sided PCBs comprises two groups of coils801and802with opposite winding directions, which represent one part of the first coil and second coil on the closed Rogowski coil with N dual-sided PCBs, respectively.

The coil800is provided with two external access points, i.e.803,804. The external access point803is taken as the starting point of the coil801, and the external access point804is taken as the starting point of the coil802. The external access point803is connected with the first coil part on the upper dual-sided PCB, and the external access point804is connected with the second coil part thereon.

The coil800is composed of multiple identical composition units in series connection, andFIG. 8Ashows a composition unit807. As shown inFIG. 8A,FIG. 8BandFIG. 8C, the center of composition unit807and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor105, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit comprises one cycle of wire turn of two groups of coils with opposite winding directions. The composition unit807comprises a cycle of wire turn806on the coil801and a cycle of wire turn807on the coil802, and the two cycles of wire turns are adjacent closely.FIG. 8Bshows a top layer part808of the wire turn806and a top layer part809of the wire turn807on the composition unit807. The top layer part808of the wire turn808is adjacent with the top layer part809of the wire turn807closely,FIG. 8Cshows a bottom layer part810of the wire turn806and a bottom layer part811of the wire turn807on the composition unit807. The bottom layer part810of the wire turn806is adjacent with the bottom layer part811of the wire turn807closely.

FIG. 7shows that the closed Rogowski coil with N dual-sided PCBs laminated can be formed by means of series connection for the coils700and800on the dual-sided PCB.FIG. 7shows that the external access point705of the coil700on the dual-sided PCBs is connected with the external access point803on the first coil part of the coil800on the dual-sided PCBs, the external access point706is connected with the external access point804on the second coil part of the dual-sided PCBs, and the external access points703and704are taken as the signal output ends of the closed Rogowski coil.

FIG. 9shows local details of the coil900on the NthPCB in the closed Rogowski coil with N dual-sided PCBs.FIG. 9Ashows a laminating layer on the local top layer and bottom layer of the closed Rogowski coil with single dual-sided PCB900,FIG. 9Bshows a local top layer of the closed Rogowski coil with single dual-sided PCB900, andFIG. 9Cshows a local bottom layer of the closed Rogowski coil with single dual-sided PCB900.

The laminating layer on the top layer and bottom layer of a composition unit900on the N dual-sized PCBs, as shown inFIG. 9A, comprises a laminating layer part of a cycle of wire turn918on the coil920and a laminating layer part of a cycle of wire turn919on the other group of coil921with opposite winding direction. The laminating layer part of a cycle of wire turn918on the coil920comprises an incoming line901, a wiring line907, a through hole909, a through hole904and an outgoing line906. The laminating layer part of a cycle of wire turn919on the coil921comprises an incoming line902, a wiring line908, a through hole910, a through hole903and an outgoing line905.

The top layer of a composition unit900on the closed PCB Rogowski coil900, as shown inFIG. 9B, comprises a top layer part of a cycle of wire turn918on the coil920and a top layer part of a cycle of wire turn919on the other group of coil921with opposite winding direction. The top layer part of a cycle of wire turn918on the coil920comprises a through hole909, a wiring line914and a through hole904. The top layer part of a cycle of wire turn919on the coil921comprises an incoming line902, a wiring line915, a through hole910, a through hole903and an outgoing line905.

The bottom layer of a composition unit900on the closed PCB Rogowski coil900, as shown inFIG. 9C, comprises a bottom layer part of a cycle of wire turn918on the coil920and a bottom layer part of a cycle of wire turn919on the other group of coil921with opposite winding direction. The bottom layer part of a cycle of wire turn918on the coil920comprises an incoming line901, a wiring line916, a through hole909, a through hole904and an outgoing line906. The bottom layer part of a cycle of wire turn919on the coil921comprises a through hole910, a wiring line917and a through hole903.

As shown inFIG. 9A,FIG. 9BandFIG. 9C, the rectangular winding part of a cycle of wire turn918on the coil920of the closed PCB Rogowski coil900is composed of a wiring line914, a through hole909, a wiring line916and a through hole904, wherein the wiring line914on the top layer of the rectangular winding part and the wiring line916on the bottom layer are overlapped in the direction vertical to the surface of PCB. The rectangular winding part of a cycle of wire turn919on the other group of coil921with opposite winding direction is composed of a wiring line917, a through hole910, a wiring line915and a through hole903, wherein the wiring line917on the bottom layer of the rectangular winding part and the wiring line915on the top layer are overlapped in the direction vertical to the surface of PCB.

As shown inFIG. 9A,FIG. 9BandFIG. 9C, the rectangular winding section directions of a cycle of wire turn918and a cycle of wire turn919on the composition unit900of the closed PCB Rogowski coil900are along the radial direction of the centers of closed PCB Rogowski coil900and winding section, or the magnetic line with the centers of various composition units on the closed PCB Rogowski coil900is in the normal direction in the center of the winding section.

As shown inFIG. 9A,FIG. 9BandFIG. 9C, the rectangular winding section directions of a cycle of wire turn918and a cycle of wire turn919on the composition unit900of the closed PCB Rogowski coil900are vertical to the radial direction of the centers of closed PCB Rogowski coil900and winding section, or the magnetic line with the centers of various composition units on the closed PCB Rogowski coil900is in the tangential direction in the center of the winding section.

As shown inFIG. 9A,FIG. 9BandFIG. 9C, the first composition unit of the closed PCB Rogowski coil900is provided with an external access point911, which is connected with the incoming line of the first wire turn on the coil920of the first composition unit, and the first composition unit of the closed PCB Rogowski coil900is provided with an external access point912, which is connected with the incoming line of the first wire turn on the other group of coil921with opposite winding direction of the first composition unit. The external access point911is connected with the first coil part on the upper dual-sided PCB, and the external access point912is connected with the second coil part, thereon.

As shown inFIG. 9A,FIG. 9BandFIG. 9C, two outgoing lines between the through hole922of the coil920and the through hole923of the other group of coil921on the last composition unit913of the closed PCB Rogowski coil900are directly connected through a wiring line924to realize the series connection between two groups of coils920and921with opposite winding directions on the closed PCB Rogowski coil900.

(III) Opened Rogowski Coil with Two PCBs

The opened Rogowski coil with two PCBs capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, and each PCB is provided with one part of the first coil and the second coil.

The opened Rogowski coil with two PCBs capable of resisting interference of external magnetic field specifically comprises two PCBs, each of which is provided with two external access points, i.e. the first external access point and the second external access point. The first external access point on each PCB is the starting point of the first coil thereon and the second external access point is the ending point of the second coil thereon.

Two connection modes are provided for two PCBs: the first external access points of two PCBs are connected directly, the second external access points of two PCBs are taken as two signal output ends of the opened Rogowski coil with two PCBs, i.e. the first signal output end and the second signal output end; the second external access points of two PCBs are connected directly, the first access points of two PCBs are taken as two signal output ends of the opened Rogowski coil with two PCBs, i.e. the first signal output end and the second signal output end. The PCB with the first signal output end is the 1stPCB, and the PCB with the second signal output end is the 2ndPCB.

Each one of the 1stPCB and the 2ndPCB is composed of multiple identical composition units in series connection, each of which comprises the cycles of wire turns of the first coil and the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm. One cycle of wire turn on the first coil of each composition unit on each PCB of the opened Rogowski coil with two PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. One cycle of wire turn on the second coil of each composition unit on each PCB of the opened Rogowski coil with two PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle.

The incoming line at one cycle of wire turn on the first coil of the first composition unit on the 1stPCB is connected with the first external access point on the 1stPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit on the 1stPCB is connected with the second external access point on the 1stPCB. The incoming line at one cycle of wire turn on the first coil of the first composition unit on the 1stPCB is connected with the first external access point on the 1stPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit on the 1stPCB is connected with the second external access point on the 1stPCB.

The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the 1stPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the 1stPCB to realize the series connection between the first coil and the second coil on the 1stPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the 2ndPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the 2ndPCB to realize the series connection between the first coil and the second coil on the 2ndPCB.

For the opened Rogowski coil with two PCBs capable of resisting interference of external magnetic field, the section composed of two cycles of wire turns on each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the opened Rogowski coil with two PCBs capable of resisting interference of external magnetic field, the centers of the composition units on each PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction (strength direction of the magnetic field) of the magnetic line passing through the section center of the winding line.

In the opened Rogowski coil with two PCBs, the PCB is a dual-sided PCB, wherein the first coil and the second coil are located on the upper and lower surfaces of the PCB, so the opened Rogowski coil with two PCBs can be called an opened Rogowski coil with two dual-sided PCBs.

The opened Rogowski coil with two dual-sized PCBs capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, and each dual-sized PCB is provided with one part of the first coil and the second coil.

The opened Rogowski coil with two PCBs capable of resisting interference of external magnetic field specifically comprises two dual-sized PCBs, each of which is provided with two external access points, i.e. the first external access point and the second external access point. The first external access point on each dual-sized PCB is the starting point of the first coil thereon and the second external access point is the ending point of the second coil thereon.

Two connection modes are provided for two PCBs: the first external access points of two PCBs are connected directly, the second external access points of two PCBs are taken as two signal output ends of the opened Rogowski coil with two PCBs, i.e. the first signal output end and the second signal output end; the second external access points of two PCBs are connected directly, the first access points of two PCBs are taken as two signal output ends of the opened Rogowski coil with two PCBs, i.e. the first signal output end and the second signal output end. The PCB with the first signal output end is the 1stPCB, and the PCB with the second signal output end is the 2ndPCB.

Each dual-sided one of the 1stPCB and the 2ndPCB is composed of multiple identical composition units in series connection, each of which comprises the cycles of wire turns of the first coil and the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

One cycle of wire turn on the first coil of each composition unit on each dual-sided PCB of the opened Rogowski coil with two dual-sided PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. One cycle of wire turn on the second coil of each composition unit on each dual-sided PCB of the opened Rogowski coil with two dual-sided PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle.

The incoming line at one cycle of wire turn on the first coil of the first composition unit on the 1stPCB is connected with the first external access point on the 1stPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit on the 1stPCB is connected with the second external access point on the 1stPCB. The incoming line at one cycle of wire turn on the first coil of the first composition unit on the 2ndPCB is connected with the first external access point on the 2ndPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit on the 2ndPCB is connected with the second external access point on the 2ndPCB.

The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the 1stPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the 1stPCB to realize the series connection between the first coil and the second coil on the 1stPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the 2ndPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the 2ndPCB to realize the series connection between the first coil and the second coil on the 2ndPCB.

For the opened Rogowski coil with two dual-sided PCBs capable of resisting interference of external magnetic field, the section composed of two cycles of wire turns on each composition unit by surrounding is vertical to the surface of dual-sided PCB, the section composed of the winding lines by surrounding is located on the cross section of dual-sided PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the opened Rogowski coil with two dual-sized PCBs capable of resisting interference of external magnetic field, the centers of the composition units on each dual-sized PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is close to the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction (strength direction of the magnetic field) of the magnetic line passing through the section center of the winding line.

FIG. 10shows a specific embodiment of the disclosure, or an opened Rogowski coil with two dual-sided PCBs1000capable of resisting interference of external magnetic field, which is suitable, for measuring the current flowing on a current-carrying conductor113vertically passing through the center of opened PCB Rogowski coil1000, and the magnetic line of AC magnetic field generated by the current is a circle of taking the center of opened PCB Rogowski coil1000as the center of a circle.FIG. 10Ashows a laminating layer on the top layer and bottom layer of the opened Rogowski coil with two dual-sided PCBs,FIG. 10Bshows a top layer of the opened Rogowski coil with two dual-sided PCBs, andFIG. 100shows a bottom layer of the opened Rogowski coil with two dual-sided PCBs.

The opened Rogowski coil with two dual-sided PCBs1000comprises two halves of dual-sided PCB Rogowski coils, i.e. the coil1001and the coil1002. The coil1001comprises two groups of coils with opposite winding directions, i.e. the coil1003and the coil1004, both of which form a half dual-sided PCB Rogowski coil1001. The coil1002comprises two groups of coils with opposite winding directions, i.e. the coil1005and the coil1006, both of which form a half dual-sided PCB Rogowski coil1002.

The coil1000is provided with four external access points, i.e.1007,1008,1009,1010. The external access point1008is taken as the starting point of the coil1003, and the external access point1007is taken as the ending point of the coil1004. The external access point1010is taken as the starting point of the coil1005, and the external access point1009is taken as the ending point of the coil1006.

The coils1001and1002can be used for forming the opened Rogowski coil with two dual-sided PCBs in two ways as follows:

The external access point1007and the external access point1009are taken as the signal output ends of the opened Rogowski coil with two dual-sided PCBs, and the external access point1008is directly connected with the external access point1010for connecting the coils1001and1002;

The external access point1008and the external access point1010are taken as the signal output ends of the opened Rogowski coil with two dual-sided PCBs, and the external access point1007is directly connected with the external access point1009for connecting the coils1001and1002;

Half a coil1001of the opened dual-sided PCB Rogowski coil is composed of multiple identical composition units in series connection, andFIG. 10Ashows a composition unit1011. As shown inFIG. 10A,FIG. 10BandFIG. 10C, the center of composition unit1011and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor113, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit on half a coil1001of the opened dual-sided PCB Rogowski coil1000comprises two groups of coils with opposite winding directions: respective one cycle of wire turn of the coils1003and1004; the composition unit1011comprises a cycle of wire turn1013of the coil1003and a cycle of wire turn1014of the coil1004, and the two cycles of wire turns are adjacent closely.FIG. 10Bshows a top layer part1017of the wire turn1013and a top layer part1018of the wire turn1014on the composition unit1011. The top layer part1017of the wire turn1013is adjacent with the top layer part1018of the wire turn1014closely,FIG. 10Cshows a bottom layer part1021of the wire turn1013and a bottom layer part1022of the wire turn1014on the composition unit1011. The bottom layer part1021of the wire turn1013is adjacent with the bottom layer part1022of the wire turn1014closely.

Half a coil1002of the opened dual-sided PCB Rogowski coil1000is composed of multiple identical composition units in series connection, andFIG. 10Ashows a composition unit1012. As shown inFIG. 10A,FIG. 10BandFIG. 10C, the center of composition unit1012and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor113, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit on half a coil1002of the opened dual-sided PCB Rogowski coil1000comprises two groups of coils with opposite winding directions: respective one cycle of wire turn of the coils1005and1006; the composition unit1012comprises a cycle of wire turn1015of the coil1005and a cycle of wire turn1016of the coil1006, and the two cycles of wire turns are adjacent closely.FIG. 5Bshows a top layer part1019of the wire turn1015and a top layer part1020of the wire turn1016on the composition unit1012. The top layer part1019of the wire turn1015is adjacent with the top layer part1020of the wire turn1016closely,FIG. 5Cshows a bottom layer part1023of the wire turn1015and a bottom layer part1024of the wire turn1016on the composition unit1012. The bottom layer part1023of the wire turn1015is adjacent with the bottom layer part1024of the wire turn1016closely.

FIG. 11shows local details on the right of half a coil101on the opened Rogowski coil with two dual-sided PCBs1100according to the specific embodiment in the disclosure.FIG. 11Ashows a laminating layer on the local top layer and bottom layer on the right of half a coil101on the opened Rogowski coil with two dual-sided PCBs1100,FIG. 11Bshows a local top layer andFIG. 6Cshows a local bottom layer on the right thereof.

The laminating layer on the top layer and bottom, layer of a composition unit1100of half a coil101on the opened Rogowski coil with two dual-sided PCBs100, as shown inFIG. 11A, comprises a laminating layer part of a cycle of wire turn1111on the coil103and a laminating layer part of a cycle of wire turn1112on the other group of coil104with opposite winding direction. The laminating layer part of a cycle of wire turn1111on the coil103comprises an incoming line1101, a wiring line1107, a through hole1109, a through hole1103and an outgoing line1105. The laminating layer part of a cycle of wire turn1112on the coil104comprises an incoming line1102, a wiring line1108, a through hole1110, a through hole1104and an outgoing line1106.

The top layer of a composition unit1100of half a coil101on the opened Rogowski coil with two dual-sided PCBs100, as shown inFIG. 11B, comprises a top layer part of a cycle of wire turn1111on the coil103and a top layer part of a cycle of wire turn1112on the other group of coil104with opposite winding direction. The top layer part of a cycle of wire turn1111on the coil103comprises an incoming line1101, a wiring line1113, a through hole1109, a through hole1103and an outgoing line1105. The top layer part of a cycle of wire turn1112on the coil104comprises a through hole1110, a wiring line1114and a through hole1104.

The bottom layer of a composition unit1100of half a coil101on the opened Rogowski coil with two dual-sided PCBs100, as shown inFIG. 11C, comprises a bottom layer part of a cycle of wire turn1111on the coil103and a top layer part of a cycle of wire turn1112on the other group of coil104with opposite winding direction. The bottom layer part of a cycle of wire turn1111on the coil103comprises a through hole1109, a wiring line1115and a through hole1103. The bottom layer part of a cycle of wire turn1112on the coil104comprises an incoming line1102, a wiring line1116, a through hole1110, a through hole1104and an outgoing line1106.

As shown inFIG. 11A,FIG. 11BandFIG. 11C, the rectangular winding part of a cycle of wire turn1111on the coil103is composed of a wiring line1113, a through hole1109, a wiring line1115and a through hole1104, wherein the wiring line1113on the top layer of the rectangular winding part and the wiring line1115on the bottom layer are overlapped in the direction vertical to the surface of PCB. The rectangular winding part of a cycle of wire turn1112on the other group of coil104with opposite winding direction is composed of a wiring line1116, a through hole1110, a wiring line1114and a through hole1104, wherein the wiring line1116on the bottom layer of the rectangular winding part and the wiring line1114on the top layer are overlapped in the direction vertical to the surface of PCB.

As shown inFIG. 11A,FIG. 11BandFIG. 11C, the rectangular winding section directions of a cycle of wire turn1111on the coil103and a cycle of wire turn1112on the coil104are approximately along the radial direction of the centers of opened Rogowski coil with two dual-sized PCBs1100and winding section, or the magnetic line with the centers of various composition units on the opened Rogowski coil with two dual-sized PCBs100is in the normal direction in the center of the winding section.

As shown inFIG. 11A,FIG. 11BandFIG. 11C, the rectangular winding section directions of a cycle of wire turn1111on the coil103and a cycle of wire turn1112on the coil104are approximately vertical to the radial direction of the centers of opened Rogowski coil with two dual-sized PCBs100and winding section, or the magnetic line with the centers of various composition units on the opened Rogowski coil with two dual-sized PCBs100is in the tangential direction in the center of the winding section.

As shown inFIG. 11A,FIG. 11BandFIG. 11C, the first composition unit on the half a coil101of the opened Rogowski coil with two dual-sized PCBs1100is provided with an external access point108, which is connected with the incoming line of the first wire turn on the coil103of the first composition unit. The first composition unit on the half a coil101of the opened Rogowski coil with two dual-sized PCBs1100is provided with an external access point107, which is connected with the incoming line of the first wire turn on the other group of coil104with opposite winding direction.

FIG. 12shows local details on the left of half a coil on the opened Rogowski coil with two dual-sided PCBs according to the specific embodiment in the disclosure.FIG. 12Ashows a laminating layer on the local top layer and bottom layer on the left of half a coil on the opened Rogowski coil with two dual-sided PCBs,FIG. 12Bshows a local top layer andFIG. 12Cshows a local bottom layer on the left thereof.

As shown inFIG. 12A,FIG. 12BandFIG. 12C, the outgoing line from the through hole1202of the coil203on the last composition unit1201of half a coil201on the opened Rogowski coil with two dual-sided PCBs is directly connected with the outgoing line from the through hole1203on the other group of coil204with opposite winding direction through the wiring line1204to realize the series connection between two groups of coils203and204with opposite winding directions of half a coil201on the opened Rogowski coil with two dual-sided PCBs.

(IV) Opened Rogowski Coil with Multiple (N≥3) PCBs

The opened Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, and each PCB is provided with one part of the first coil and the second coil.

The opened Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field is specifically composed of two halves of PCB Rogowski coils, each of which is composed of N PCBs by laminating. Each half of the PCB Rogowski coil is provided with two signal output ends, i.e. the first signal output end and the second signal output end. The PCB with the first and second signal output ends is the 1stPCB, the PCB adjacent with the 1stPCB is the 2ndPCB, if N≥3, the rest can be done in the same manner, it is the 3rdPCB till the NthPCB is present.

Four external access points are set from the 1stPCB to the (N−1)thPCB on each half of the PCB Rogowski coil, i.e. the first external access point, the second external access point, the third external access point and the fourth external access point, wherein the first external access point and the third external access point are the starting point and the ending point of the first coil from the 1stPCB to the (N−1)thPCB, respectively; and the second external access point and the fourth external access point are the starting point and the ending point of the second coil from the 1stPCB to the (N−1)thPCB, respectively. The NthPCB on each half of the PCB Rogowski coil is provided with two external access points, i.e. the first external access point and the second external access point, wherein the first external access point is the starting point of the first coil on the NthPCB, and the second external access point is the starting point of the second coil on the NthPCB.

The first external access point on the 1stPCB on each half of the PCB Rogowski coil is the first signal output end, and the second external access point on the 1stPCB is the second signal output end. The third external access point on the upper one of the adjacent and laminated PCBs on each half of the PCB Rogowski coil is connected with the first external access point on the lower one to realize the series connection between the first coil part on the upper PCB and the first coil part on the lower PCB to form a complete first coil. The fourth external access point on the upper one of the adjacent and laminated PCBs on each half of the PCB Rogowski coil is connected with the second external access point on the lower one to realize the series connection between the second coil part on the upper PCB and the second coil part on the lower PCB to form a complete second coil. The first coil and the second coil on each half of the PCB Rogowski coil are directly connected, in series on the NthPCB to form half an opened Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field.

Two connection modes are provided for two halves of PCB Rogowski coils on the opened Rogowski coil with multiple PCBs: the first external access points of two halves of PCB Rogowski coils are connected directly, the second external access points of two halves of PCB Rogowski coils are taken as two signal output ends of the opened Rogowski coil with multiple PCBs, i.e. the first signal output end and the second signal output end; the second external access points of two halves of Rogowski coils are connected directly, and the first access points of two halves of PCB Rogowski coils are taken as two signal output ends of the opened Rogowski coil with multiple PCBs, i.e. the first signal output end and the second signal output end.

Each PCB of the opened Rogowski coil with multiple PCBs is composed of multiple identical composition units in series connection, each of which comprises the cycles of wire turns of the first coil and the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm. One cycle of wire turn on the first coil of each composition unit on each PCB of the opened Rogowski coil with multiple PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. One cycle of wire turn on the second coil of each composition unit on each PCB of the opened Rogowski coil with multiple PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes among different layers by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle.

The incoming line at one cycle of wire turn on the first coil of the first composition unit from the 1stPCB to the NthPCB on the opened Rogowski coil with multiple PCBs is connected with the first external access point from the 1stPCB to the NthPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit from the 1stPCB to the NthPCB is connected with the second external access point from the 1stPCB to the NthPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the third external access point from the 1stPCB to the (N−1)thPCB, and the outgoing line at one cycle of wire turn on the second coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the fourth external access point from the 1stPCB to the (N−1)thPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the NthPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the NthPCB to realize the series connection between the first coil and the second coil on the NthPCB.

For the opened Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field, the section composed of two cycles of wire turns on each composition unit by surrounding is vertical to the surface of PCB, the section composed of the winding lines by surrounding is located on the cross section of PCB, and the wiring paths of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the opened Rogowski coil with multiple PCBs capable of resisting interference of external magnetic field, the centers of the composition units on each PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately along the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction (strength direction of the magnetic field) of the magnetic line passing through the section center of the winding line.

In the opened Rogowski coil with multiple PCBs, the PCB is a dual-sided PCB, wherein the first coil and the second coil are located on the upper and lower surfaces of the PCB, so the opened Rogowski coil with multiple PCBs can be called an opened Rogowski coil with multiple dual-sided PCBs.

The opened Rogowski coil with multiple dual-sized PCBs capable of resisting interference of external magnetic field comprises two groups of series-connected coils in opposite winding direction, i.e. a first coil and a second coil, and each dual-sized PCB is provided with one part of the first coil and the second coil.

The opened Rogowski coil with multiple dual-sized PCBs capable of resisting interference of external magnetic field is specifically composed of two halves of PCB Rogowski coils, each of which is composed of N dual-sized PCBs by laminating. Each half of the Rogowski coil is provided with two signal output ends, i.e. the first signal output end and the second signal output end. The PCB with the first and second signal output ends is the 1stPCB, the PCB adjacent with the 1stPCB is the 2ndPCB, if N≥3, the rest can be done in the same manner, it is the 3rdPCB till the NthPCB is present.

Four external access points are set from the 1stPCB to the (N−1)thPCB on each half of the PCB Rogowski coil, i.e. the first external access point, the second external access point, the third external access point and the fourth external access point, wherein the first external access point and the third external access point are the starting point and the ending point of the first coil from the 1stPCB to the (N−1)thPCB, respectively; and the second external access point and the fourth external access point are the starting point and the ending point of the second coil from the 1stPCB to the (N−1)thPCB, respectively. The NthPCB on each half of the PCB Rogowski coil is provided with two external access points, i.e. the first external access point and the second external access point, wherein the first external access point is the starting point of the first coil on the NthPCB, and the second external access point is the starting point of the second coil on the NthPCB.

The first external access point on the 1stPCB on each half of the PCB Rogowski coil is the first signal output end, and the second external access point on the 1stPCB is the second signal output end. The third external access point on the upper one of the adjacent and laminated PCBs on each half of the PCB Rogowski coil is connected with the first external access point on the lower one to realize the series connection between the first coil part on the upper PCB and the first coil part on the lower PCB to form a complete first coil. The fourth external access point on the upper one of the adjacent and laminated PCBs on each half of the PCB Rogowski coil is connected with the second external access point on the lower one to realize the series connection between the second coil part on the upper PCB and the second coil part on the lower PCB to form a complete second coil. The first coil and the second coil on each half of the PCB Rogowski coil are directly connected in series on the NthPCB to form half an opened Rogowski coil with multiple dual-sized PCBs capable of resisting interference of external magnetic field.

Two connection modes are provided for two halves of PCB Rogowski coils on the opened Rogowski coil with multiple PCBs: the first external access points of two halves of PCB Rogowski coils are connected directly, the second external access points of two halves of PCB Rogowski coils are taken as two signal output ends of the opened Rogowski coil with multiple dual-sized PCBs, i.e. the first signal output end and the second signal output end; the second external access points of two halves of Rogowski coils are connected directly, and the first access points of two halves of PCB Rogowski coils are taken as two signal output ends of the opened Rogowski coil with multiple dual-sized PCBs, i.e. the first signal output end and the second signal output end.

Each dual-sized PCB of the opened Rogowski coil with multiple dual-sized PCBs is composed of multiple identical composition units in series connection, each of which comprises the cycles of wire turns of the first coil and the second coil, and the two cycles of wire turns are adjacent closely. That two cycles of wire turns are adjacent closely can be understood as: the minimum space between two cycles of wire turns is equal to the minimum safety space between the PCBs, the minimum safety space between the PCBs is related to the technology of PCB, e.g. the minimum safety space between the PCBs is 6 mil, or 0.1524 mm.

One cycle of wire turn on the first coil of each composition unit on each dual-sided PCB of the opened Rogowski coil with multiple dual-sided PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the first coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. One cycle of wire turn on the second coil of each composition unit on each dual-sided PCB of the opened Rogowski coil with multiple dual-sided PCBs comprises an incoming line, a winding line and an outgoing line, wherein the incoming line and outgoing line are respectively connected with the wire turns of the second coils on the upper composition unit and the lower composition unit, and the winding line is composed of wirings and through holes between the top layer and the bottom layer by surrounding. Specifically, the wiring path on the top layer is overlapped with that on the bottom layer. The section of winding lines composed of the wirings on the top layer and bottom layer and two through holes by surrounding is similar to a rectangle.

The incoming line at one cycle of wire turn on the first coil of the first composition unit from the 1stPCB to the NthPCB on the opened Rogowski coil with multiple dual-sized PCBs is connected with the first external access point from the 1stPCB to the NthPCB, and the incoming line at one cycle of wire turn on the second coil of the first composition unit from the 1stPCB to the NthPCB is connected with the second external access point from the 1stPCB to the NthPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the third external access point from the 1stPCB to the (N−1)thPCB, and the outgoing line at one cycle of wire turn on the second coil of the last composition unit from the 1stPCB to the (N−1)thPCB is connected with the fourth external access point from the 1stPCB to the (N−1)thPCB. The outgoing line at one cycle of wire turn on the first coil of the last composition unit on the NthPCB is directly connected with the outgoing line at one cycle of wire turn on the second coil of the last composition unit on the NthPCB to realize the series connection between the first coil and the second coil on the NthPCB.

For the opened Rogowski coil with multiple dual-sided PCBs capable of resisting interference of external magnetic field, the section composed of two cycles of wire turns on each composition unit by surrounding is vertical to the surface of dual-sided PCB, the section composed of the winding lines by surrounding is located on the cross section of dual-sided PCB, and the wiring paths on the top layer and bottom layer of the winding lines are overlapped in the direction vertical to the surface of PCB.

For the opened Rogowski coil with multiple dual-sized PCBs capable of resisting interference of external magnetic field, the centers of the composition units on each dual-sized PCB are uniformly distributed on a magnetic line of magnetic field for generating current to be measured, the direction of the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately along the normal direction of the magnetic line passing through the section center of the winding line, and the section surrounded by the winding lines at two cycles of wire turns of all the composition units is approximately vertical to the tangential direction (strength direction of the magnetic field) of the magnetic line passing through the section center of the winding line.

FIG. 13shows a specific embodiment of the disclosure, or an opened Rogowski coil with multiple dual-sided PCBs1300composed of N layers of dual-sized PCBs by laminating from the 1stlayer to the (N−1)thlayer, which is suitable for measuring the current flowing on a current-carrying conductor113vertically passing through the center of opened PCB Rogowski coil1300, and the magnetic line of AC magnetic field generated by the current is a circle of taking the center of opened PCB Rogowski coil1300as the center of a circle.FIG. 13Ashows a laminating layer on the top layer and bottom layer of the dual-sized PCB from the 1stlayer to the (N−1)thlayer on the opened Rogowski coil with multiple dual-sided PCBs1300composed of N layers of dual-sized PCBs by laminating,FIG. 13Bshows a top layer andFIG. 13Cshows a bottom layer thereof.

The dual-sized PCB from the 1stlayer to the (N−1)thlayer on the opened Rogowski coil with multiple dual-sided PCBs1300composed of N layers of dual-sized PCBs by laminating comprises two halves of dual-sided PCB Rogowski coils, i.e. the coils1301and1302. The coil1301comprises two groups of coils with opposite winding directions, i.e. the coil1303and the coil1304, both of which form a half dual-sided PCB Rogowski coil1301. The coil1302comprises two groups of coils with opposite winding directions, i.e. the coil1305and the coil1306, both of which form a half dual-sided PCB Rogowski coil1302.

The coil1301is provided with four external access points, i.e.1307,1308,1317,1318. The external access point1308is taken as the starting point of the coil1303, and the external access point1317is taken as the ending point of the coil1303. The external access point1307is taken as the starting point of the coil1304, and the external access point1318is taken as the ending point of the coil1304.

The coil1302is provided with four external access points, i.e.1309,1310,1319,1320. The external access point1310is taken as the starting point of the coil1305, and the external access point1319is taken as the ending point of the coil1305. The external access point1309is taken as the starting point of the coil1306, and the external access point1320is taken as the ending point of the coil1306.

The coil1301is composed of multiple identical composition units in series connection, andFIG. 13Ashows a composition unit1311. As shown inFIG. 13A,FIG. 13BandFIG. 13C, the center of composition unit1311and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor113, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit of the coil1301comprises two groups of coils with opposite winding directions: one cycle of wire turns of the coils1303and1304. The composition unit1311comprises a cycle of wire turn1313on the coil1303and a cycle of wire turn1314on the coil1304, and the two cycles of wire turns are adjacent closely.FIG. 13Bshows a top layer part1321of the wire turn1313and a top layer part1322of the wire turn1314on the composition unit1311. The top layer part1321of the wire turn1313is adjacent with the top layer part1322of the wire turn1314closely,FIG. 13Cshows a bottom layer part1326of the wire turn1313and a bottom layer part1327of the wire turn1314on the composition unit1311. The bottom layer part1326of the wire turn1313is adjacent with the bottom layer part1327of the wire turn1314closely.

The coil1302is composed of multiple identical composition units in series connection, andFIG. 13Ashows a composition unit1312. As shown inFIG. 13A,FIG. 13BandFIG. 13C, the center of composition unit1312and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor113, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit of the coil1302comprises two groups of coils with opposite winding directions: one cycle of wire turns of the coils1305and1306. The composition unit1312comprises a cycle of wire turn1315on the coil1305and a cycle of wire turn1316on the coil1306, and the two cycles of wire turns are adjacent closely.FIG. 13Bshows a top layer part1323of the wire turn1315and a top layer part1324of the wire turn1316on the composition unit1312. The top layer part1323of the wire turn1315is adjacent with the top layer part1324of the wire turn1316closely,FIG. 10Cshows a bottom layer part1328of the wire turn1315and a bottom layer part1329of the wire turn1316on the composition unit1312. The bottom layer part1328of the wire turn1315is adjacent with the bottom layer part1329of the wire turn1316closely.

FIG. 14shows a dual-sized PCB on the Nthlayer of the opened Rogowski coil with multiple dual-sided PCBs composed of N layers of dual-sized PCBs by laminating according to the specific embodiment in the disclosure.FIG. 14Ashows a laminating layer on the top layer and bottom layer of the dual-sized PCB on the Nthlayer of the opened Rogowski coil with multiple dual-sided PCBs500composed of N layers of dual-sized PCBs by laminating,FIG. 14Bshows a top layer andFIG. 14Cshows a bottom layer thereof.

The dual-sized PCB on the Nthlayer of the opened Rogowski coil with multiple dual-sided PCBs500composed of N layers of dual-sized PCBs by laminating comprises two halves of dual-sided PCB Rogowski coils, i.e. the coils1401and1402. The coil1401comprises two groups of coils with opposite winding directions, i.e. the coil1403and the coil1404, both of which form a half dual-sided PCB Rogowski coil1401. The coil1402comprises two groups of coils with opposite winding directions, i.e. the coil1406and the coil1406, both of which form a half dual-sided PCB Rogowski coil1402.

The coil1401is provided with two external access points, i.e.1407,1408. The external access point1408is taken as the starting point of the coil1403, and the external access point1407is taken as the starting point of the coil1404.

The coil1402is provided with two external access points, i.e.1409,1410. The external access point1410is taken as the starting point of the coil1405, and the external access point1409is taken as the starting point of the coil1406.

The coil1401is composed of multiple identical composition units in series connection, andFIG. 14Ashows a composition unit1411. As shown inFIG. 14A,FIG. 14BandFIG. 14C, the center of composition unit1411and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor113, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit of the coil1401comprises two groups of coils with opposite winding directions: one cycle of wire turns of the coils1403and1404. The composition unit1411comprises a cycle of wire turn1413on the coil1403and a cycle of wire turn1414on the coil1404, and the two cycles of wire turns are adjacent closely.FIG. 14Bshows a top layer part1417of the wire turn1413and a top layer part1418of the wire turn1414on the composition unit1411. The top layer part1417of the wire turn1413is adjacent with the top layer part1418of the wire turn1414closely,FIG. 14Cshows a bottom layer part1421of the wire turn1413and a bottom layer part1422of the wire turn1414on the composition unit1411. The bottom layer part1421of the wire turn1413is adjacent with the bottom layer part1422of the wire turn1414closely.

The coil1402is composed of multiple identical composition units in series connection, andFIG. 14Ashows a composition unit1412. As shown inFIG. 14A,FIG. 14BandFIG. 14C, the center of composition unit1412and the centers of other composition units are located on a circular magnetic line generated by the current flowing on the current-carrying conductor113, and various composition units are uniformly distributed on the circular magnetic line.

Each composition unit of the coil1402comprises two groups of coils with opposite winding directions: one cycle of wire turns of the coils1405and1406. The composition unit1412comprises a cycle of wire turn1415on the coil1405and a cycle of wire turn1416on the coil1406, and the two cycles of wire turns are adjacent closely.FIG. 14Bshows a top layer part1419of the wire turn1415and a top layer part1420of the wire turn1416on the composition unit1412. The top layer part1419of the wire turn1415is adjacent with the top layer part1420of the wire turn1416closely,FIG. 14Cshows a bottom layer part1423of the wire turn1415and a bottom layer part1424of the wire turn1416on the composition unit1412. The bottom layer part1423of the wire turn1415is adjacent with the bottom layer part1424of the wire turn1416closely.

FIG. 15shows local details on the right of the dual-sized PCB from the 1stPCB to the (N−1)thPCB of the half opened Rogowski coil with multiple dual-sided PCBs composed of N layers of dual-sized PCBs by laminating according to the specific embodiment in the disclosure.FIG. 15Ashows a laminating layer on the top layer and bottom layer of the dual-sized PCB from the 1stPCB to the (N−1)thPCB of the half opened Rogowski coil with multiple dual-sided PCBs composed of N layers of dual-sized PCBs by laminating,FIG. 15Bshows a top layer andFIG. 15Cshows a bottom layer thereof.

The laminating layer on the top layer and bottom layer of a composition unit1500on the coil301, as shown inFIG. 15A, comprises a laminating layer part of a cycle of wire turn1511on the coil303and a laminating layer part of a cycle of wire turn1512on the other group of coil304with opposite winding direction. The laminating layer part of a cycle of wire turn1511on the coil303comprises an incoming line1501, a wiring line1507, a through hole1509, a through hole1503and an outgoing line1505. The laminating layer part of a cycle of wire turn1512on the coil304, comprises an incoming line1502, a wiring line1508, a through hole1510, a through hole1504and an outgoing line1506.

The top layer of a composition unit1500on the coil301, as shown inFIG. 15B, comprises a top layer part of a cycle of wire turn1511on the coil303and a top layer part of a cycle of wire turn1512on the other group of coil304with opposite winding direction. The top layer part of a cycle of wire turn1511on the coil303comprises an incoming line1501, a wiring line1513, a through hole1509, a through hole1503and an outgoing line1505. The top layer part of a cycle of wire turn1512on the coil304comprises a through hole1510, a wiring line1514and a through hole1504.

The bottom layer of a composition unit1500on the coil301, as shown inFIG. 15C, comprises a bottom layer part of a cycle of wire turn1511on the coil303and a bottom layer part of a cycle of wire turn1512on the other group of coil304with opposite winding direction. The bottom layer part of a cycle of wire turn1511on the coil303comprises a through hole1509, a wiring line1515and a through hole1503. The bottom layer part of a cycle of wire turn1512on the coil304comprises an incoming line1502, a wiring line1516, a through hole1510, a through hole1504and an outgoing line1506.

As shown inFIG. 15A,FIG. 15BandFIG. 15C, the rectangular winding part of a cycle of wire turn1511on the coil303is composed of a wiring line1513, a through hole1509, a wiring line1515and a through hole1504, wherein the wiring line1513on the top layer of the rectangular winding part and the wiring line1515on the bottom layer are overlapped in the direction vertical to the surface of PCB. The rectangular winding part of a cycle of wire turn1512on the other group of coil304with opposite winding direction is composed of a wiring line1516, a through hole1510, a wiring line1514and a through hole1504, wherein the wiring line1516on the bottom layer of the rectangular winding part and the wiring line1514on the top layer are overlapped in the direction vertical to the surface of PCB.

As shown inFIG. 15A,FIG. 15BandFIG. 15C, the rectangular winding section directions of a cycle of wire turn1511on the coil303and a cycle of wire turn1512on the coil304are approximately along the radial direction of the centers of opened Rogowski coil with multiple dual-sized PCBs300and winding section, or the magnetic line with the centers of various composition units on the opened Rogowski coil with multiple dual-sized PCBs300is in the normal direction in the center of the winding section.

As shown inFIG. 15A,FIG. 15BandFIG. 15C, the rectangular winding section directions of a cycle of wire turn1511on the coil303and a cycle of wire turn1512on the coil304are approximately along the radial direction of the centers of opened Rogowski coil with multiple dual-sized PCBs300and winding section, or the magnetic line with the centers of various composition units on the opened Rogowski coil with multiple dual-sized PCBs300is in the tangential direction in the center of the winding section.

As shown inFIG. 15A,FIG. 15BandFIG. 15C, the first composition unit on the half a coil301of the opened Rogowski coil with two dual-sized PCBs300is provided with an external access point308, which is connected with the incoming line of the first wire turn on the coil303of the first composition unit. The first composition unit on the coil301is provided with an external access point307, which is connected with the incoming line of the first wire turn on the other group of coil304with opposite winding direction.

FIG. 16shows local details on the left of the dual-sized PCB from the 1stPCB to the (N−1)thPCB of the half opened Rogowski coil with multiple dual-sided PCBs1600composed of N layers of dual-sized PCBs by laminating according to the specific embodiment in the disclosure.FIG. 16Ashows a laminating layer on the top layer and bottom layer of the dual-sized PCB on the Nthlayer of the half opened Rogowski coil with multiple dual-sided PCBs1600composed of N layers of dual-sized PCBs by laminating,FIG. 163shows a top layer andFIG. 16Cshows a bottom layer thereof.

As shown inFIG. 16A,FIG. 16BandFIG. 16C, the outgoing line from the through hole1602of the coil403on the last composition unit1601of the Nthdual-sized PCB on the half opened Rogowski coil with multiple dual-sided PCBs composed of N layers of dual-sized PCBs by laminating is directly connected with the outgoing line from the through hole1603of the other group of coil404with opposite winding direction through the wiring line1604on the top layer to realize the series connection between two groups of coils403and404with opposite winding directions of the Nthdual-sized PCB on the half opened Rogowski coil with multiple dual-sided PCBs composed of N layers of dual-sized PCBs by laminating.

The above is a good specific implementation mode of the disclosure only, but the protective range of the disclosure is not limited to this, the change or replacement easily thought by any technical personnel familiar with the technical field shall be included in the protective range of the disclosure. Thus, the protective range of the disclosure shall be subject to the protective range in the Claims.