Medium or High Voltage Instrument Voltage Transformer

A medium or high voltage sensor includes a medium or high voltage sensing unit; a primary connection; a cable connection; and at least one fixation part; wherein the primary connection is connected to a first terminal of the medium or high voltage sensor unit; wherein the cable connection is connected to a second terminal of the medium or high voltage sensor unit; wherein the at least one fixation part is located at a base end of the medium or high voltage sensor unit; and wherein the at least one fixation part is configured to connect to an external structure.

CROSS-REFERENCE TO RELATED APPLICATIONS

The instant application claims priority to European Patent Application No. 23174869.0, filed May 23, 2023, which is incorporated herein in its entirety by reference.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a medium or high voltage instrument voltage transformer, to a kit of parts to form a medium or high voltage sensor, and to a method of manufacturing a medium or high voltage sensor.

BACKGROUND OF THE INVENTION

Medium or high voltage sensor designs, can be based on a capacitive, resistive, or capacitive/resistive combination (hereafter called impedance) voltage divider, where for example a voltage drop occurs across several impedance elements in series between a medium or high voltage and ground or earth potential, and where sensing across the last impedance element and ground potential enables the medium or high voltage itself to be sensed.

Presently outdoor medium or high voltage sensor designs are usually bulky, and are cast in outdoor-graded thermoset material, and are made in relatively low volumes. It can also be difficult to mount or fix both indoor and outdoor medium or high voltage sensors at the required locations. This contributes to high costs.

BRIEF SUMMARY OF THE INVENTION

It would be advantageous to have an improved medium or high voltage sensor that is suitable to be mounted in different location, including that for outdoor use. In an aspect, there is provided a medium or high voltage sensor, comprising: a medium or high voltage sensing unit; a primary connection; a cable connection; and at least one fixation part. The primary connection is connected to a first terminal of the medium or high voltage sensor unit. The cable connection is connected to a second terminal of the medium or high voltage sensor unit. The at least one fixation part is located at a base end of the medium or high voltage sensor unit. The at least one fixation part is configured to connect to an external structure.

DETAILED DESCRIPTION OF THE INVENTION

FIGS.1-5, relate to a medium or high voltage sensor, a kit of parts to form a medium or high voltage sensor, and a method of manufacturing a medium or high voltage sensor.

In an example, a medium or high voltage sensor5comprises: a medium or high voltage sensing unit2; a primary connection10; a cable connection6; and at least one fixation part3,4. The primary connection is connected to a first terminal of the medium or high voltage sensor unit. The cable connection is connected to a second terminal of the medium or high voltage sensor unit. The at least one fixation part is located at a base end of the medium or high voltage sensor unit. The at least one fixation part is configured to connect to an external structure.

Thus, a number of different fixation parts can be made that can be used to fix to different external structures, but have a common part of the structure that can fit to the same medium or high voltage sensor unit. Thus, the same medium or high voltage sensor unit can be used in different situations and be able to be fixed to different external structures by choosing the appropriate at least one fixation part to fix to the external structure.

According to an example, the at least one fixation part comprises a first fixation part3and a second fixation part4. An inner surface of the first fixation part is located adjacent to an outer surface of the medium or high voltage sensor unit. The outer surface of the medium or high voltage sensor unit is cylindrically shaped or conically shaped. The second fixation part is connected to the first fixation part.

In an example, the inner surface of the first fixation part is in contact with the outer surface of the medium or high voltage sensor unit. In an example, the inner surface of the first fixation part is connected to the outer surface of the medium or high voltage sensor unit. In an example, the inner surface of the first fixation part is glued to the outer surface of the medium or high voltage sensor unit.

According to an example, an inner surface of the first fixation part is cylindrically shaped or conically shaped. In an example, the inner surface of the first fixation part has the same shape as the outer surface of the medium or high voltage sensor unit.

According to an example, the second fixation part is connected to an end portion of the first fixation part. According to an example, the end portion of the first fixation part is annular shaped.

According to an example, the medium or high voltage sensor unit comprises an impedance voltage divider. According to an example, the first terminal of the medium or high voltage sensor unit is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider. According to an example, the second terminal of the medium or high voltage sensor unit is a terminal at a position between capacitive and/or resistive elements of the impedance voltage divider.

According to an example, the at least one fixation part is connected to a third terminal of the medium or high voltage sensor unit. According to an example, the third terminal is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider.

According to an example, the sensor comprises an earthing wire7. The earthing wire is connected to the at least one fixation part to provide an earth connection for the medium or high voltage sensor unit. According to an example, the sensor comprises an earthing wire7. The earthing wire is connected to the earth terminal located within one fixation part to provide an earth connection for the medium or high voltage sensor unit.

According to an example, the sensor comprises a silicone rubber sleeve1. The silicone rubber sleeve is located around an outer surface of the medium or high voltage sensor unit. In an example, the silicone rubber sleeve is in contact with the outer surface of the medium or high voltage sensor unit. According to an example, the silicone rubber sleeve is located around an outer surface of the primary connection. In an example, the silicone rubber sleeve is in contact with the outer surface of the primary connection. In an example, the silicone rubber sleeve is located around an outer surface of the at least one fixation part. In an example, the silicone rubber sleeve is in contact with the outer surface of the at least one fixation part. In an example, the silicone rubber sleeve is designed for outdoor applications.

Thus, a medium or high voltage sensor unit that cannot itself be utilized in outdoor situations has now in effect been made weatherproof.

As is clear from the figures, a kit of parts is also provided to form a medium or high voltage sensor5. The kit of parts comprises: a medium or high voltage sensing unit2; a primary connection10; a cable connection6; and at least one fixation part3,4. The primary connection is configured to connect to a first terminal of the medium or high voltage sensor unit. The cable connection is configured to connect to a second terminal of the medium or high voltage sensor unit. The at least one fixation part is configured to be located at a base end of the medium or high voltage sensor unit. The at least one fixation part is configured to connect to an external structure.

In an example, the at least one fixation part comprises a first fixation part3and a second fixation part4. An inner surface of the first fixation part is configured to be located adjacent to an outer surface of the medium or high voltage sensing unit. The outer surface of the medium or high voltage sensing unit is cylindrically shaped or conically shaped. The second fixation part is configured to be connected to the first fixation part.

In an example, the inner surface of the first fixation part is configured to be in contact with the outer surface of the medium or high voltage sensing unit. In an example, the inner surface of the first fixation part is configured to be connected to the outer surface of the medium or high voltage sensor unit. In an example, the inner surface of the first fixation part is configured to be glued to the outer surface of the medium or high voltage sensor unit.

In an example, the first fixation part is made of thermoset or thermoplasting material, in liquid state filled, into the silicone sleeve with medium or high voltage sensing unit pre-assembled, thus tightly adhering to the outer surface of the medium or high voltage sensing unit. Once the thermoset of thermoplastic material solidifies, it will ensure mechanical properties required.

In an example, the first fixation part is common to the medium or high voltage sensor unit, and the second fixation part is selected from a number of different second fixation parts dependent upon the external structure to which the fixation is to be made. Thus, in an example the kit comprises a plurality of second fixation parts that are different to each other but which all are configured to connect to the same first fixation part, and where every different second fixation part can connect to different external structures with respect to the required fixation to be used.

In an example, the first fixation part is made of non-conductive material. In an example, the second fixation part is made of electrically conductive material. The second fixation part is electrically connected to the third terminal of the medium or high voltage sensor. In an example, the second fixation part is made of electrically non-conductive material. In that case it needs to provide a possibility to access, directly or through an additional terminal, the third terminal of the medium or high voltage sensor.

In an example, an inner surface of the first fixation part is cylindrically shaped or conically shaped. In an example, the inner surface of the first fixation part has the same shape as the outer surface of the medium or high voltage sensing unit. In an example, the second fixation part is configured to connect to an end portion of the first fixation part. In an example, the end portion of the first fixation part is annular shaped.

In an example, the medium or high voltage sensing unit comprises a capacitive and/or resistive voltage divider. In an example, the first terminal of the medium or high voltage sensing unit is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider. In an example, the second terminal of the medium or high voltage sensor unit is a terminal at a position between capacitive and/or resistive elements of the impedance voltage divider.

In an example, the at least a portion of one fixation part is configured to be connected to a third terminal of the medium or high voltage sensing unit. In an example, the third terminal is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider.

In an example, the kit comprises an earthing wire7. The earthing wire is configured to be connected to the at least a portion of one fixation part to provide an earth connection for the medium or high voltage sensor unit.

In an example, the kit comprises a silicone rubber sleeve1. The silicone rubber sleeve is configured to be located around an outer surface of the medium or high voltage sensor unit. In an example, the silicone rubber sleeve is configured to be in contact with the outer surface of the medium or high voltage sensor unit. In an example, the silicone rubber sleeve is configured to be located at least partly around an outer surface of the primary connection. In an example, the silicone rubber sleeve is configured to be in contact with the outer surface of the primary connection. In an example, the silicone rubber sleeve is configured to be located around an outer surface of the at least one fixation part. In an example, the silicone rubber sleeve is configured to be in contact with the outer surface of the at least one fixation part. In an example, the silicone rubber sleeve is designed for outdoor applications.

A method of manufacturing a medium or high voltage sensor5, comprises: connecting a primary connection10to a first terminal of a medium or high voltage sensor unit2; connecting a cable connection6to a second terminal of the medium or high voltage sensor unit; locating at least one fixation part3,4at a base end of the medium or high voltage sensor unit; and the at least one fixation part is configured to connect to an external structure.

In an example, the at least one fixation part comprises a first fixation part3and a second fixation part4, and the method comprises: locating an inner surface of the first fixation part adjacent to an outer surface of the medium or high voltage sensing unit, wherein the outer surface of the medium or high voltage sensing unit is cylindrically shaped or conically shaped; and connecting the second fixation part to the first fixation part.

In an example, the method comprises passing the first fixation part over a top end of the medium or high voltage sensing unit. In an example, the method comprises contacting the inner surface of the first fixation part with the outer surface of the medium or high voltage sensing unit. In an example, method comprises connecting the inner surface of the first fixation part to the outer surface of the medium or high voltage sensing unit. In an example, the method comprises gluing the inner surface of the first fixation part to the outer surface of the medium or high voltage sensing unit.

In an example, the method comprises greasing of the inner surface of the first fixation part to the outer surface of the medium or high voltage sensing unit. Thus using a lubricant facilitates assembly.

Thus, as shown in the figures the medium or high voltage sensing unit2can have a conical shaped lower outer end section and a first fixation part3can have a similarly shaped inner surface. The first fixation part3is then put over the end of the medium or high voltage sensing unit2and slid downwards until both surfaces, at least partly, mate together. The components could be glued, but need not be. The second fixation part4is then selected dependent upon how the sensor is to be fixed, i.e. where bolt holes are located etc. for external fixation. The first fixation part3has bolt holes, and each of the second fixation parts have common holes that enable the second fixation part4to be bolted at the underside of the medium or high voltage sensing unit2to the first fixation part. The whole fixation formed by first fixation part3and the second fixation part4is then secured attached to the medium or high voltage sensing unit2without there having be any attached between the fixation parts and the medium or high voltage sensing unit2as such. This facilitates replacement etc., and by having the fixation part3,4in two sections, one common section can be used along with different second sections to attach in different situation.

The medium or high voltage sensing unit2could have a cylindrical shaped lower or base section, and then the first fixation part3has a cylindrical inner shape that closely fits the outer cylindrical shape of the medium or high voltage sensing unit2. In this situation, the first fixation part can then be glued to the medium or high voltage sensing unit2, and then the second fixation part chose as required, and connected to the first fixation part.

In an example, an inner surface of the first fixation part is cylindrically shaped or conically shaped. In an example, the inner surface of the first fixation part has the same or similar shape as the outer surface of the medium or high voltage sensing unit. In an example, the method comprises connecting the second fixation part to an end portion of the first fixation part. In an example, the end portion of the first fixation part is annular shaped.

In an example, the method comprises passing the first fixation part over the top end of the medium or high voltage sensing unit such that the end port of the first fixation part is directed towards the base end of the medium or high voltage sensing unit and then the second fixation part is moved towards the first fixation part from the opposite direction and connected to the first fixation part to cover a bottom surface of the medium or high voltage sensor unit. In an example, the medium or high voltage sensing unit comprises a capacitive, resistive or capacitive/resistive combination voltage divider.

In an example, the first terminal of the medium or high voltage sensing unit is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider. In an example, the second terminal of the medium or high voltage sensing unit is a terminal at a position between capacitive and/or resistive elements of the impedance voltage divider. In an example, the method comprises connecting the at least one fixation part to a third terminal of the medium or high voltage sensing unit. In an example, the third terminal is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider. In an example, the method comprises connecting an earthing wire7to the at least a portion of one fixation part to provide an earth connection for the medium or high voltage sensing unit.

In an example, the method comprises locating a silicone rubber sleeve1around an outer surface of the medium or high voltage sensing unit. In an example, the silicone rubber sleeve is in contact with the outer surface of the medium or high voltage sensing unit. In an example, the method comprises locating the silicone rubber sleeve around at least part of an outer surface of the primary connection. In an example, the silicone rubber sleeve is in at least partial contact with the outer surface of the primary connection. In an example, the method comprises locating the silicone rubber sleeve around an outer surface of the at least one fixation part. In an example, the silicone rubber sleeve is in contact with the outer surface of the at least one fixation part. In an example, the silicone rubber sleeve is designed for outdoor applications.

A method of manufacturing a medium or high voltage sensor5, comprises: connecting a primary connection10to a first terminal of a medium or high voltage sensor unit2; connecting a cable connection6to a second terminal of the medium or high voltage sensor unit; filling the remaining bottom part of silicone rubber sleeve1with thermoplastic or thermoset material, thus forming at least portion of one fixation part3,4at a base end of the medium or high voltage sensor unit; and the at least one fixation part is configured to connect to an external structure.

Other steps of manufacturing the medium or high voltage sensor5are as discussed above. Several detailed specific embodiments are now described, where reference is again made toFIGS.1-5.

The new development described here can in effect be considered to relate to a voltage sensor with an additional base part that enables mechanical fixation to external structures. The new development also relates to a simple and light construction of an outdoor-grade medium- or high-voltage voltage sensor. In the new development the voltage sensor, that can be for example an existing voltage sensor designed for indoor application, can be used, and this is placed into a silicone sleeve with sheds designed for outdoor application.

The new development can utilize a standard voltage sensor and parts that can be produced in high volumes, with certain fixation parts that can be common for all uses and with other fixation parts that can be designed for a variety of different situation. Thus, in effect a modular construction that can be used in outdoor situations, with different fixation requirements is enables, achieving lower costs for an overall solution as well as standardization in production.

The following specific embodiments focusses on a voltage sensor that has the silicone sleeve for outdoor use. Thus, the new development uses an indoor-graded voltage sensor2designed for indoor voltage measurements in a cable termination. Such a standardized voltage sensor, or at least part of its design, is inserted into a standard silicone rubber sleeve1, which will ensure protection and performance under outdoor conditions. Additional base part or parts3and4can be used to within—by part3—and cover—by part4—the remaining part of the sleeve, in order to accommodate fixation means to be used to mount the sensor on external structures.

FIG.1shows schematics of the light outdoor medium- or high-voltage voltage sensor5construction. The different parts can be considered to be a kit of parts that be used to form a voltage sensor5.FIG.2shows a cross-section of the light medium- or high-voltage voltage sensor.

FIG.2shows a cross-section of the assembled voltage sensor. Apart from standard parts described above, the voltage sensor is equipped with outdoor-grade output cable6. The outdoor cable6can be a standard outdoor coaxial cable terminated by a connector or just by wires. Furthermore, the voltage sensor5is shown equipped with earthing wire7. However alternatively or additionally earthing can also be provided through the fixation means8of an external structure that can be at ground or earth potential. Example of both options are shown inFIG.3.

In the situation when the voltage sensor5is standing on a support structure (not shown), which is typically metallic construction that is connected to earth, it is preferable to use the mechanical fixations means8for grounding connection as well. Mechanical fixations means are used primarily for mechanical positioning of the voltage sensor, in order to ensure proper placement of such a voltage sensor.

In the situation when the voltage sensor5is not standing on or fixed to any kind of metallic and grounded support structure, but rather hanging on a wire whose voltage is to be measured or standing on an insulated support structure, a ground connection can be provided through the outdoor-graded or outdoor protected earthing wire7or alternatively through shielding of the output cable6.

Examples of termination for the primary terminal10to be connected to the wire whose voltage is to be measured is shown inFIGS.4-5.FIG.4shows a connection screw20that is fixing the additional bar21, to which the connection to medium- or high-voltage is to be made, to the voltage sensor5.FIG.5shows a threaded rod23screwed to the voltage sensor5and fixed by a fixation nut24. Voltage connection can be realized by a cable eyelet22which is then fixed to the threaded rod23by additional nut25.

The Light outdoor medium- or high-voltage voltage sensor5thus consists of at least a part of indoor graded voltage sensor2covered by outdoor-graded shell1, fixation means and output cable. Mechanical fixation means8can be at voltage sensor base (standing) with medium/high voltage connection21at the top of the outdoor housing. Mechanical fixation means20or23can be at the top of the outdoor housing, together with medium/high voltage connection22. An output cable can be an outdoor-graded output cable. An output cable can be an indoor-graded output cable, which goes through other surrounding structures or parts that provide outdoor protection. An outdoor-graded shell can be made of a silicone-based material.

An outdoor-graded shell can be made from outdoor thermoplast or thermoset material. An outdoor shell can be tightly slipped/pulled over the indoor voltage sensor (to provide a mechanical connection). An outdoor shell can be cast over at least part of the indoor voltage sensor.

In an example, the at least one fixation part comprises a first fixation part and a second fixation part. An inner surface of the first fixation part is located adjacent to an outer surface of the medium or high voltage sensor unit. The outer surface of the medium or high voltage sensor unit is cylindrically shaped or conically shaped. The second fixation part is connected to the first fixation part.

In an example, an inner surface of the first fixation part is cylindrically shaped or conically shaped. In an example, the second fixation part is connected to an end portion of the first fixation part. In an example, the end portion of the first fixation part is annular shaped. In an example, the medium or high voltage sensor unit comprises an impedance voltage divider. In an example, the medium or high voltage sensor unit comprises an instrument voltage transformer or low-power instrument voltage transformer designed for indoor use. In an example, the first terminal of the medium or high voltage sensor unit is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider. In an example, the second terminal of the medium or high voltage sensor unit is a terminal at a position between capacitive and/or resistive elements of the impedance voltage divider.

In an example, the at least one fixation part is connected to a third terminal of the medium or high voltage sensor unit. In an example, the third terminal is a terminal at an end position of a plurality of capacitive and/or resistive elements of the impedance voltage divider.

In an example, sensor comprises an earthing wire or at least an earthing terminal. The earthing wire or the at least an earthing terminal is connected to the at least one fixation part to provide an earth connection for the medium or high voltage sensor unit. In an example, the sensor comprises an earthing wire. The earthing wire is connected to the earth terminal located within one fixation part to provide an earth connection for the medium or high voltage sensor unit.

In an example, the sensor comprises a silicone rubber sleeve. The silicone rubber sleeve is located around an outer surface of the medium or high voltage sensor unit. In an example, the silicone rubber sleeve is located around an outer surface of the primary connection.

In an aspect, there is provided a kit of parts to form a medium or high voltage sensor, comprising: a medium or high voltage sensing unit; a primary connection; a cable connection; and at least one fixation part.

The primary connection is configured to connect to a first terminal of the medium or high voltage sensor unit. The cable connection is configured to connect to a second terminal of the medium or high voltage sensor unit. The at least one fixation part is configured to be located at a base end of the medium or high voltage sensor unit. The at least one fixation part is configured to connect to an external structure.

In an aspect, there is provided a method of manufacturing a medium or high voltage sensor, comprising: connecting a primary connection to a first terminal of a medium or high voltage sensing unit; connecting a cable connection to a second terminal of the medium or high voltage sensor unit; locating at least one fixation part at a base end of the medium or high voltage sensing unit; and wherein the at least one fixation part is configured to connect to an external structure.

In an aspect, there is provided a method of manufacturing a medium or high voltage sensor, comprising: connecting a primary connection to a first terminal of a medium or high voltage sensor unit; connecting a cable connection to a second terminal of the medium or high voltage sensor unit; filling the remaining bottom part of silicone rubber sleeve with thermoplastic or thermoset material, thus forming at least portion of one fixation part at a base end of the medium or high voltage sensor unit; and wherein the at least one fixation part is configured to connect to an external structure.