Patent Description:
Conventionally, a switch gear device utilizes an opening and closing mechanism that selectively opens and closes an electrical circuit for instance via opening and closing electrical contacts embedded within the switch gear device. Such opening and closing mechanism typically contain several mechanically interconnected parts prone to wear out consequently limiting a longevity of whole switch gear device. As example of a switch gear device can be found for instance in <CIT>. Additionally, an external environment may further influence the longevity of the whole switch gear device causing the opening and closing mechanism to degrade prematurely when exposed for instance to an entry of humidity or excessive temperatures.

An impact of a switch gear device unexpected failure may be in some cases quite severe. Thus, rather than waiting for the opening and closing mechanism of the switch gear device to fail it is desirable to monitor its proper function and preemptively diagnose when the switch gear device needs to be replaced or repaired.

Therefore, it would be advantageous to have a switch gear device with a simple and a low cost monitored opening and closing mechanism.

One aspect of the present disclosure is directed to a monitored circuit breaker. The monitored circuit breaker comprises a switch gear, a plurality of magnets, a magnetic field sensor and a processing circuitry. The switch gear includes an opening/closing mechanism adapted to selectively open and close an electrical circuit. The opening/closing mechanism comprises a pivotally mounted shaft configured to rotate about a pivot axis as the opening/closing mechanism moves between an open and a closed state. The magnets of the plurality of magnets are spaced from each other and fixedly attached to the shaft. The magnetic field sensor is configured to sense a magnetic field generated by each magnet of the plurality of magnets as the shaft pivots. Each magnet of the plurality of magnets defines a different angular position of the shaft in which the magnetic field sensor senses a respective magnet of the plurality of magnets. The processing circuitry is configured to compute a first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses a magnetic field generated by at least two magnets of the plurality of magnets as the shaft pivots in one direction.

Additionally, the magnets of the plurality of magnets may be positioned equidistant from the pivot axis of the shaft.

Additionally, the magnetic field sensor may comprise a magneto resistive or a hall effect type sensor for the magnetic field sensing.

Additionally, the magnetic field sensor may comprise a switch type hall effect sensor and the magnetic field sensor may be configured to generate an electrical signal when it senses a magnetic field generated by a magnet of the plurality of magnets.

Additionally, the magnetic field sensor may comprise a unipolar Hall effect switch type sensor.

Additionally, the plurality of magnets may comprise four discrete magnets where each of the four discrete magnets defines an angular position of the shaft that corresponds to a specific position of the opening/closing mechanism between its open and closed state.

Additionally, an open position of the opening/closing mechanism may be defined as an angular position of the shaft of <NUM> degrees and the closed position of the opening/closing mechanism may be defined as an angular position of the shaft of A degrees. The four magnets may include a first magnet which may define a first angular position of the shaft of a1 degrees, a second magnet which may define a second angular position of the shaft of a2 degrees, a third magnet which may define a third angular position of the shaft of a3 degrees and a fourth magnet which may define a fourth angular position of the shaft of a4 degrees, with a4>a3>a2>a1.

Additionally, a1 may be comprised between <NUM>% of A and <NUM>% of A, a2 may be comprised between <NUM>% of A and <NUM>% of A, a3 may be comprised between <NUM>% of A and <NUM>% of A and a4 may be comprised between <NUM>% of A and <NUM>% of A.

Additionally, A may be comprised between <NUM> and <NUM> degrees.

Additionally, A may be comprised between <NUM> and <NUM> degrees, a1 may be comprised between <NUM> and <NUM> degrees, a2 may be comprised between <NUM> and <NUM> degrees, a3 may be comprised between <NUM> and <NUM> degrees and a4 may be comprised between <NUM> and <NUM> degrees.

Additionally, the processing circuitry may be configured to compute the first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the fourth and the third magnets as the shaft rotates and the opening/closing mechanism moves from the closed position to the open state.

Additionally, the processing circuitry may be configured to compute a second angular speed of the shaft based on signals provided by the magnetic field sensor when it registers the fourth and the second magnets as the shaft rotates and the opening/closing mechanism moves from the closed position to the open state.

Additionally, the processing circuitry may be further configured to compute a third angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the second and the first magnets as the shaft continues to rotate and the opening/closing mechanism moves from the closed position to the open state.

Additionally, the processing circuitry may be configured to compute a fourth angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the third and fourth magnets as the shaft rotates and the opening/closing mechanism moves from the open position to the closed state.

A further aspect is directed to a method of monitoring a circuit breaker. The method comprising: rotating a shaft of an opening/closing mechanism and selectively opening or closing by the opening/closing mechanism an electrical circuit of a switch gear comprised in the circuit breaker, wherein the shaft is pivotally mounted to rotate about a pivot axis and the shaft has a fixedly attached a plurality of magnets spaced from each other; sensing by a magnetic field sensor a magnetic field generated by at least two magnets of the plurality of magnets as the shaft rotates, wherein each magnet of the plurality of magnets defines a different angular position of the shaft in which the magnetic field sensor senses the magnets; and computing by a processing circuitry a first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the at least two magnets of the plurality of magnets as the shaft rotates in one direction.

Additionally, in the method the plurality of magnets may comprise four discrete magnets where each of the four discrete magnets defines a different angular position of the shaft that corresponds to a specific travel position of the opening/closing mechanism between its open and closed state.

Additionally, in the method an open position of the opening/closing mechanism may be defined as an angular position of the shaft of <NUM> degrees and the closed position of the opening/closing mechanism is defined as an angular position of the shaft of A degrees. The four magnets may include a first magnet which defines a first angular position of the shaft of a1 degrees, a second magnet which defines a second angular position of the shaft of a2 degrees, a third magnet which defines a third angular position of the shaft of a3 degrees and a fourth magnet which defines a fourth angular position of the shaft of a4 degrees, with a4>a3>a2>a1.

Additionally, in the method a1 may be comprised between <NUM>% of A and <NUM>% of A, a2 may be comprised between <NUM>% of A and <NUM>% of A, a3 may be comprised between <NUM>% of A and <NUM>% of A and a4 may be comprised between <NUM>% of A and <NUM>% of A.

Additionally, in the method A may be comprised between <NUM> and <NUM> degrees.

Additionally, in the method A may be comprised between <NUM> and <NUM> degrees, a1 may be comprised between <NUM> and <NUM> degrees, a2 may be comprised between <NUM> and <NUM> degrees, a3 may be comprised between <NUM> and <NUM> degrees and a4 may be comprised between <NUM> and <NUM> degrees.

Additionally, the method may comprise: rotating the shaft of the opening/closing mechanism and opening the electrical circuit of the switch gear; and computing by the processing circuitry the first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the fourth and the third magnet as the shaft rotates.

Additionally, the method may comprise: rotating the shaft of the opening/closing mechanism and opening the electrical circuit of the switch gear; and computing a second angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the fourth and the second magnet as the shaft rotates.

Additionally, the method may further comprises continue rotating the shaft and computing a third angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the second and the first magnet as the shaft rotates.

Additionally, the method may comprise rotating the shaft of the opening/closing mechanism and closing the electrical circuit of the switch gear and computing a fourth angular speed of the shaft based on signals provided by the magnetic field sensor when it senses the third and fourth magnets as the shaft rotates in one direction.

In a further aspect, the method of monitoring a circuit breaker can be used in conjunction with, or as a part of, the monitored circuit breaker as defined above.

Further areas of applicability will become apparent from the description herein. The description and specific examples in the summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

Other features and advantages of the invention appear from the following detailed description of some of its embodiments, given by way of non-limiting example, and with reference to the accompanying drawings, in which:.

As used herein, an element or step recited in the singular and proceeded with the word "a" or "an" should be understood as not excluding plural of the elements or steps, unless such exclusion is explicitly stated. Further, references to "one embodiment" are not intended to be interpreted as excluding the existence of additional embodiments that also incorporate the recited features. Moreover, unless explicitly stated to the contrary, embodiments "comprising" or "having" an element or a plurality of elements having a particular property may include additional elements not having that property.

In the figures, the same references denote identical or similar elements, unless stated otherwise. In the drawings, the size of each element or a specific portion constituting the element is exaggerated, omitted, or schematically shown for convenience and clarity of description. Thus, the size of each component may not entirely reflect the actual size. In the case where it is judged that the detailed description of the related known functions or constructions may unnecessarily obscure the gist of the present disclosure, such explanation will be omitted.

Turning now to <FIG>, a simplified perspective view of a monitored switch gear device <NUM> is depicted. The monitored switch gear device <NUM> comprises of a switch gear <NUM> including an opening/closing mechanism. The opening/closing mechanism selectively opens and closes an electrical circuit (not shown). The electrical circuit may comprise one or more electrical contacts actuated by the opening/closing mechanism. The electrical contacts may be comprised within the switch gear <NUM> and actuated by the opening/closing mechanism. The opening/closing mechanism has a pivotally mounted shaft <NUM> that rotates in the direction of double arrow <NUM> about a pivot axis <NUM> as the opening/closing mechanism moves between an open and a closed state. The shaft <NUM> may be pivotally held <NUM> in a bracket <NUM> made for instance of a metal sheet or a plastic composite. The shaft <NUM> may be on one side pivotally held inside a plain bearing attached to the bracket <NUM> or held within the bracket <NUM>. The shaft <NUM> may have attached a plurality of magnets (shown in <FIG>) that are spaced spaced from each other. The magnets may be attached to the shaft via an optional holder <NUM> coupled to the shaft <NUM>. The monitored switch gear device <NUM> further has a magnetic field sensor <NUM> configured to sense a magnetic field generated by each magnet of the plurality of magnets as the shaft <NUM> pivots. The magnetic field sensor <NUM> may be rigidly coupled to the bracket <NUM> so that it does not move when the shaft pivots <NUM>. The magnetic field sensor <NUM> may face a one side of the holder <NUM> where the plurality of magnets is held. The magnetic field sensor <NUM> may sense the magnetic field generated by each magnet of the plurality of magnets (shown in <FIG>) as the shaft <NUM> pivots <NUM> about the pivot axis <NUM> and magnets of the plurality of magnets passes the magnetic field sensor <NUM>. The magnetic field sensor <NUM> may comprise a one or more magneto resistive and/or hall effect type sensor(s) for the magnetic field sensing. When the magnetic field sensor comprises a magneto resistive type sensor it may be a giant magnetoresistance (GMR) type sensor. The magnetic field sensor <NUM> may also comprise a one or more switch type Hall effect sensor. The magnetic field sensor <NUM> may be configured to generate an electrical signal when it senses a magnet of the plurality of magnets. Sensing a magnet by the magnetic field sensor <NUM> means sensing or registering a magnetic field of the magnet by the magnetic field sensor <NUM>. A processing circuitry <NUM> is depicted in proximity of the magnetic field sensor <NUM>, however, the processing circuitry <NUM> may be located elsewhere. The processing circuitry <NUM> computes a first angular speed of the shaft <NUM> based on signals provided by the magnetic field sensor <NUM> when it senses at least two magnets of the plurality of magnets as the shaft <NUM> pivots in one direction.

Moving to <FIG>, an exemplary perspective simplified view of a portion <NUM> of the monitored switch gear device <NUM> is depicted. In this exemplary view the shaft <NUM> is pivotable about a pivot axis <NUM> as shown by the arrows <NUM>. The plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> are attached to the shaft <NUM> via a holder <NUM> connected to the shaft <NUM>. Shown in the figure the plurality of magnets comprises four discrete magnets <NUM>, <NUM>, <NUM>, <NUM> where each of the four discrete magnets <NUM>, <NUM>, <NUM>, <NUM> defines an angular position of the shaft that corresponds to a specific position of the opening/closing mechanism between its open and closed state. There may be a different number, for instance <NUM>, <NUM> or <NUM> or more, of magnets comprised in the plurality of magnets. The magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> are spaced from each another and located on a one side of the holder <NUM>. The magnets <NUM>, <NUM>, <NUM>, <NUM> may be positioned equidistant from the pivot axis <NUM> of the shaft <NUM>. The magnetic field sensor <NUM> is located to face the side of the holder <NUM> on which the magnets <NUM>, <NUM>, <NUM>, <NUM> are arranged. The magnetic field sensor senses a magnetic field generated by each magnet <NUM>, <NUM>, <NUM>, <NUM> of the plurality of magnets as the shaft <NUM> rotates about the pivot axis <NUM> and magnets of the plurality of magnets passes the magnetic field sensor <NUM>. Then each magnet <NUM>, <NUM>, <NUM>, <NUM> of the plurality of magnets defines a different angular position of the shaft <NUM> in which the magnetic field sensor <NUM> respectively senses the magnets <NUM>, <NUM>, <NUM>, <NUM> of the plurality of magnets. The magnetic field sensor <NUM> may be attached to a printed circuit board (PCB) <NUM> to which the processing circuitry <NUM> may be also attached.

Moving to <FIG>, showing a side view of an exemplary arrangement of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> with respect to the shaft <NUM> and the magnetic field sensor <NUM>. The magnets <NUM>, <NUM>, <NUM>, <NUM> are fixedly attached to the shaft <NUM>. The shafts pivots about an axis that is perpendicular to the shown axis <NUM> and <NUM>. The magnets <NUM>, <NUM>, <NUM>, <NUM> may be attached to the shaft <NUM> via a holder as shown in <FIG>. The plurality of magnets is formed by four discrete magnets <NUM>, <NUM>, <NUM>, <NUM>, however, there may be a different number of discrete magnets such as <NUM>, <NUM>, <NUM> or more magnets. Each of the discrete magnets <NUM>, <NUM>, <NUM>, <NUM> defines an angular position <NUM>, <NUM>, <NUM>, <NUM> of the shaft <NUM> that corresponds to a specific position of the opening/closing mechanism between its open and closed state. As the shaft <NUM> pivots in one of directions <NUM> the plurality of magnets passes in proximity of the magnetic sensor <NUM>. The magnetic field sensor <NUM> senses a magnetic field of each of the discrete magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> as they pass in proximity of it. The magnetic field sensor <NUM> may be attached to a printed circuit board (PCB) <NUM> to which the processing circuitry <NUM> may be also attached. Angular movement of the opening/closing mechanism between its open and closed state is represented by an arc line with arrows A. One benefit of such angular arrangement of discrete magnets <NUM>, <NUM>, <NUM>, <NUM> in relation to the shaft <NUM> and the sensor <NUM> is that when the opening/closing mechanism moves to selectively opens or closes an electrical circuit, then via the related pivot of the shaft <NUM> a signal from the magnetic field sensor <NUM> can be utilized to monitor progress of the opening or closing of the electrical circuit and consequently monitor the switch gear operation.

Depending on the monitored switch gear, an angular position and number of discrete magnets may vary. In one exemplary implementation an open position of the opening/closing mechanism is defined as an angular position of the shaft <NUM> with respect to the sensor as <NUM> degrees and the closed position of the opening/closing mechanism is defined as an angular position of the shaft <NUM> of A degrees. The discrete magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> may include a first magnet <NUM> which defines a first angular position <NUM> of the shaft <NUM> of a1 degrees, a second magnet <NUM> which defines a second angular position <NUM> of the shaft of a2 degrees, a third magnet <NUM> which defines a third angular position <NUM> of the shaft of a3 degrees and a fourth magnet <NUM> which defines a fourth angular position <NUM> of the shaft <NUM> of a4 degrees, with a4>a3>a2>a1.

In one exemplary implementation a1 is comprised between <NUM>% of A and <NUM>% of A, a2 is comprised between <NUM>% of A and <NUM>% of A, a3 is comprised between <NUM>% of A and <NUM>% of A and a4 is comprised between <NUM>% of A and <NUM>% of A. Shafts <NUM> complete angular movement in one direction A may be comprised between <NUM> and <NUM> degrees. In yet another exemplary implementation A is comprised between <NUM> and <NUM> degrees, a1 is comprised between <NUM> and <NUM> degrees, a2 is comprised between <NUM> and <NUM> degrees, a3 is comprised between <NUM> and <NUM> degrees and a4 is comprised between <NUM> and <NUM> degrees.

Moving to <FIG>, showing an exemplary arrangement of the plurality of discrete magnets as described in the embodiment of <FIG>. As shown each discrete magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> is directionally magnetized so that it has both North and South magnetic pole on the side that passes the magnetic field sensor <NUM> as the shaft <NUM> pivots. Each discrete magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> may be a permanent magnet made of NdFeB (Neodium Iron Bore) or SmCo (Samarium Cobalt) or AlNiCo (Aluminum Nickel Cobalt) and may have its remanence Br equal or higher than <NUM>,<NUM> Tesla (<NUM><NUM> Gauss). Preferably, each discrete magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> may be a permanent magnet and may have its remanence Br comprised between <NUM> Tesla (<NUM><NUM> Gauss) and <NUM> Tesla (<NUM><NUM> Gauss). An airgap between a center of the magnetic field sensor <NUM> and a center of a respective passing magnet <NUM>, <NUM>, <NUM>, <NUM> as the shaft pivots may be comprised between <NUM> millimeter and <NUM> millimeters.

Further, the magnetic field sensor <NUM> is arranged to sense the magnetic field variation generated by both North and South magnetic poles of each discrete magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM> when the shaft <NUM> pivots as the opening/closing mechanism moves either from an open to close or a close to open position. As depicted the magnetic field sensor <NUM> may be placed on a printed circuit board (PCB) <NUM>. An optional second magnetic field sensor <NUM> may be placed on opposite side of the PCB <NUM> or both magnetic fields sensors may be placed next to each other on one side of the PCB <NUM>. The magnetic field sensor and the optional second magnetic field sensor may be of the same type and provide mutually redundant signals. One benefit of having two magnetic sensors of the same type providing redundant signals is to improve precision and reliability of the sensed shaft's <NUM> angular position. Alternatively, the magnetic field sensor <NUM> and the optional second magnetic field sensor <NUM> may be of different sensor type and/or provide a different signal. In one example the magnetic field sensor <NUM> may comprise a Hall effect switch type magnetic sensor or more specifically a unipolar Hall effect switch type sensor.

One possible example of utilization of such unipolar Hall effect switch type sensor as the magnetic field sensor <NUM> is depicted in <FIG> showing an exemplary implementation of the unipolar Hall effect switch type sensor for sensing a magnetic field generated by the discrete magnets of the plurality magnets <NUM>, <NUM>, <NUM> as they pass the unipolar Hall effect switch type sensor when the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. Arrow <NUM> shows a direction of magnets movement in time as the shaft rotates and a curve <NUM> shows an intensity of sensed magnetic field of the plurality of magnets <NUM>, <NUM>, <NUM> as they pass in time the unipolar Hall effect switch type sensor. As depicted the unipolar Hall effect switch type sensor of <FIG> may have a first and second switching point thresholds BRP, BOP triggered by a level of a positive magnetic field. In one example the magnetic field sensor <NUM> may comprise a unipolar Hall effect switch type sensor having a first switching point BRP set between <NUM> Tesla (<NUM> gauss) and <NUM> Tesla (<NUM> gauss) and the second switching point BOP set between <NUM> Tesla (<NUM> gauss) and <NUM> Tesla (<NUM> gauss). As depicted in <FIG> the first switching point BRP may be a magnetic field threshold <NUM> for switching the unipolar Hall effect type switch on and the second switching point BOP may be a magnetic field threshold <NUM> for switching the unipolar Hall effect type switch off.

Curve <NUM> depicts a switching dependence of the unipolar Hall effect switch type sensor on the intensity of the sensed magnetic field. In one example falling edges of the unipolar Hall effect switch type sensor output, as it is switched from on to off, may be used for determining time duration T1, T2 that takes two or more magnets of the plurality of magnets <NUM>, <NUM>, <NUM> to pass the unipolar Hall effect switch type sensor as the shaft rotates <NUM>, <NUM>, <NUM>, <NUM>. The time duration T1, T2 together with a known angular positions of the discrete magnets of the plurality of magnets <NUM>, <NUM>, <NUM> can be used to determine a rotational speed of the shaft <NUM>, <NUM>, <NUM>, <NUM>. As shown in <FIG> each discrete magnet of the plurality of magnets <NUM>, <NUM>, <NUM> is directionally magnetized so that it has both North and South magnetic pole on the side that passes the Hall effect switch type sensor employed as the magnetic field sensor <NUM>. There may be more than three discrete magnets of the plurality of magnets used <NUM>, <NUM>, <NUM>. Additionally, the discrete magnets <NUM>, <NUM>, <NUM> of <FIG> may be three of four magnets depicted in <FIG> and the Hall effect sensor may be used in the exemplary arrangement of the plurality of discrete magnets as depicted in <FIG> and described in the embodiment of <FIG>. One benefit of such arrangement is that it is possible to achieve a high switching point accuracy of less than <NUM> degree of shaft's rotation. Another benefit of using a Hall effect switch type magnetic sensor is its very low cost. Further benefit is in sensing robustness as the Hall effect switch reacts only to a fixed threshold level of magnetic field that is assured by the presence of both magnetic poles that the magnetic field sensor <NUM> senses for each of the discrete magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>. In case of the optional magnetic field sensor <NUM> is used it may also comprise a Hall effect switch type magnetic sensor or more specifically a unipolar Hall effect switch type magnetic field sensor.

Moving to <FIG>, an exemplary illustration showing a graph <NUM> of a shaft's <NUM>, <NUM>, <NUM>, <NUM> rotation versus time during an actuation of the opening/closing mechanism between its closed and open states. The shaft's <NUM>, <NUM>, <NUM>, <NUM> angular position versus time during the actuation of the opening/closing mechanism is graphically represented as a line <NUM>. Each intersections of the line <NUM> by a dashed line <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> ,<NUM>, and <NUM> depicts an exemplary point where a magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> passes the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. These intersections relate to specific shaft's angular positions a1, a2, a3 and a4 as defined above and shown in <FIG> that correspond to specific positions of the opening/closing mechanism between its open and closed state. As described above the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> generates a signal when it senses the magnetic field generated by the respective magnet passing the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM>. Based on the signals the processing circuitry <NUM>, <NUM>, <NUM> may compute an angular speed of the shaft <NUM>, <NUM>, <NUM>, <NUM> as the shaft pivots in one direction. The processing circuitry <NUM>, <NUM>, <NUM> may compute plurality of angular speeds of the shaft <NUM>, <NUM>, <NUM>, <NUM> as it rotates in one direction based on depicted time durations x1, x2, x3, x4, x5, x6 between the signals generated by the magnetic field sensor and known specific shaft's angular positions a1, a2, a3 and a4 defined by the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>. Each of the plurality of angular speeds then may be related to a speed of partial actuation of the opening/closing mechanism between its closed and open states. In other words, as the opening/closing mechanism actuates between its closed and open state the speed of the actuation may not be linear and may be advantageously divided into plurality of speeds each related to a particular portion of an actuation movement that can be advantageously related to a movement of a particular electrical circuit that the opening/closing mechanism selectively open and close. In one example such portions of interest may closely relate to an opening speed, closing speed, damping speed. Such portions may be further related to a rebound and holding of an electrical circuit of a circuit breaker. Graph <NUM> of FGI. <NUM> will be further used in description of flow diagrams depicting in following embodiments of a method of monitoring a switch gear device.

Moving to <FIG>, that depicts an exemplary flow diagram of a method <NUM> of monitoring a switch gear <NUM> as for example shown in <FIG> and further detailed in any of <FIG>, <FIG>. The method <NUM> may begin at step <NUM> by rotating a shaft <NUM>, <NUM>, <NUM>, <NUM> of an opening/closing mechanism and selectively opening or closing by the opening/closing mechanism an electrical circuit of the switch gear <NUM>. The shaft <NUM>, <NUM>, <NUM>, <NUM> may be pivotally mounted to rotate about a pivot axis <NUM>, <NUM> and the shaft <NUM>, <NUM>, <NUM>, <NUM> has a fixedly attached a plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> spaced from each other. The plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may be attached to the shaft <NUM>, <NUM>, <NUM>, <NUM> as shown in <FIG>, <FIG>. The method in step <NUM> senses, by a magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM>, a magnetic field generated by at least two magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. Each magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> may define a different angular position of the shaft <NUM>, <NUM>, <NUM>, <NUM> in which the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> senses a respective magnet of plurality of magnets. In step <NUM> a processing circuitry <NUM>, <NUM>, <NUM> computes a first angular speed of the shaft <NUM>, <NUM>, <NUM>, <NUM> based on signals provided by the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> when it senses the magnetic field generated by the at least two magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates in one direction. As shown in the <FIG>, <FIG> the plurality of magnets may comprise four discrete magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> ,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, where each of the four discrete magnets defines an angular position of the shaft <NUM>, <NUM>, <NUM>, <NUM> that corresponds to a specific position of the opening/closing mechanism between its open and closed state. Depending on the monitored switch gear <NUM> an angular position and number of discrete magnets may vary and there may be a different number, for instance <NUM>, <NUM> or <NUM> or more, of magnets comprised in the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> ,<NUM>, <NUM>, <NUM>, <NUM>, <NUM>. In one exemplary implementation an open position of the opening/closing mechanism is defined as an angular position of the shaft with respect to the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> of <NUM> degrees and the closed position of the opening/closing mechanism is defined as an angular position of the shaft <NUM> of A degrees. Then four discrete magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> ,<NUM>, <NUM>, <NUM>, <NUM>, <NUM> may include a first magnet <NUM>, <NUM>, <NUM> which defines a first angular position <NUM> of the shaft <NUM> of a1 degrees, a second magnet <NUM>, <NUM>, <NUM> which defines a second angular position <NUM> of the shaft of a2 degrees, a third magnet <NUM>, <NUM>,<NUM> which defines a third angular position <NUM> of the shaft of a3 degrees and a fourth magnet <NUM>, <NUM>, <NUM> which defines a fourth angular position <NUM> of the shaft <NUM> of a4 degrees, with a4>a3>a2>a1.

In one exemplary implementation, a1 is comprised between <NUM>% of A and <NUM>% of A, a2 is comprised between <NUM>% of A and <NUM>% of A, a3 is comprised between <NUM>% of A and <NUM>% of A and a4 is comprised between <NUM>% of A and <NUM>% of A. Shaft <NUM>, <NUM>, <NUM>, <NUM> complete angular movement in one direction A may be comprised between <NUM> and <NUM> degrees. In yet another exemplary implementation A is comprised between <NUM> and <NUM> degrees, a1 is comprised between <NUM> and <NUM> degrees, a2 is comprised between <NUM> and <NUM> degrees, a3 is comprised between <NUM> and <NUM> degrees and a4 is comprised between <NUM> and <NUM> degrees.

Shown in <FIG> is an exemplary flow diagram detailing an opening phase <NUM> of the method <NUM> of monitoring a switch gear <NUM>. The opening phase <NUM>, begins by rotating the shaft <NUM>, <NUM>, <NUM>, <NUM> having attached four discrete magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> each magnet defining a different angular a1, a2, a3, a4 position of the shaft <NUM>, <NUM>, <NUM>, <NUM> and opening an electrical circuit of the switch gear <NUM>. In a step <NUM> then the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> senses a magnetic field generated by at least two magnets of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. Then, in step <NUM>, the processing circuitry <NUM>, <NUM>, <NUM> computes a first angular speed of the shaft <NUM>, <NUM>, <NUM>, <NUM> based on signals provided by the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> when it senses the fourth <NUM>, <NUM>, <NUM> and the third magnet <NUM>, <NUM>, <NUM> as the shaft rotates. In <FIG> the opening phase <NUM> of the method <NUM> is illustrated as a portion of the line <NUM> that represents the shaft's <NUM>, <NUM>, <NUM>, <NUM> angular position versus actuating time as described above. Intersections of the line <NUM> by dashed lines <NUM>, <NUM>, <NUM>, <NUM> depicts exemplary points where a magnet of the plurality of magnets <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> passes, and is sensed by, the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates during the opening phase <NUM>. In the example shown in <FIG> the first angular speed relates to time durations x1 and intersections of the line <NUM> by dashed lines <NUM> and <NUM> and area <NUM> corresponding to signals provided by the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> when it senses the fourth <NUM>, <NUM>, <NUM> and the third <NUM>, <NUM>, <NUM> magnet as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. One benefit of calculating the first angular speed is that its value can be closely correlated to an opening speed, in one example an initial opening speed, of the switch gear being monitored. In such case computation of the first angular speed may provide a useful information concerning status of the switch gear <NUM> contacts being opened. Change of the first angular speed then may be indicative for instance of a corrosion or micro welds of the contacts.

In one example, as depicted in <FIG>, the opening phase <NUM> of the method <NUM> of monitoring a switch gear <NUM> may comprises a step <NUM> of rotating the shaft <NUM>, <NUM>, <NUM>, <NUM> of the opening/closing mechanism and opening the electrical circuit of the switch gear <NUM>. The opening phase <NUM> of the method <NUM> of monitoring a switch gear <NUM> may further comprises step <NUM> of computing a second angular speed of the shaft <NUM>, <NUM>, <NUM>, <NUM> based on signals provided by the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> when it senses the fourth <NUM>, <NUM>, <NUM> and the second <NUM>, <NUM>, <NUM> magnet as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. In the example shown in <FIG> the second angular speed relates to time durations x2 and intersections of the line <NUM> by dashed lines <NUM> and <NUM> and areas <NUM> and <NUM> corresponding to signals provided by the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> when it senses the fourth <NUM>, <NUM>, <NUM> and the second <NUM>, <NUM>, <NUM> magnet as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. One benefit of calculating the second angular speed is that its value can be closely correlated to an overall opening speed of the switch gear <NUM>. In such case monitoring of the first angular speed may provide a useful information concerning status of switch gear opening. Change of the second angular speed then may be indicative for instance of mechanical issues negatively influencing opening speed of the switch gear that may be an important quality for some switch gear devices such as circuit breakers or contactors.

Optionally, the opening phase <NUM> of the method <NUM> of monitoring a switch gear <NUM> may further comprises a step <NUM>, depicted on <FIG>, comprising continuation of rotating the shaft <NUM>, <NUM>, <NUM>, <NUM> and computing a third angular speed of the shaft based on signals provided by the magnetic field sensor <NUM>, <NUM>, <NUM>, <NUM> when it senses the second and the first magnet as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. In the example shown in <FIG> the third angular speed relates to time durations x3 and intersections of the line <NUM> by dashed lines <NUM> and <NUM> corresponding to signals provided by the magnetic field sensor when it senses the second <NUM>, <NUM>, <NUM> and the first <NUM>, <NUM>, <NUM> magnet as the shaft <NUM>, <NUM>, <NUM>, <NUM> rotates. One benefit of calculating the third angular speed is that its value may provide a useful information concerning status of a dampening mechanism optionally utilized in switch gears to eliminate contact bouncing upon opening.

Claim 1:
A monitored circuit breaker (<NUM>) comprising:
a switch gear (<NUM>) including an opening/closing mechanism adapted to selectively open and close an electrical circuit, the opening/closing mechanism comprising a pivotally mounted shaft (<NUM>, <NUM>, <NUM>, <NUM>) configured to rotate (<NUM>, <NUM>, <NUM>) about a pivot axis (<NUM>, <NUM>) as the opening/closing mechanism moves between an open and a closed state;
a plurality of magnets (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) spaced from each other and fixedly attached to the shaft;
a magnetic field sensor (<NUM>, <NUM>, <NUM>, <NUM>) configured to sense a magnetic field generated by each magnet of the plurality of magnets as the shaft pivots, wherein each magnet of the plurality of magnets defines a different angular position (<NUM>,<NUM>,<NUM>, <NUM>) of the shaft in which the magnetic field sensor senses a respective magnet of the plurality magnets;
a processing circuitry (<NUM>, <NUM>, <NUM>) configured to compute a first angular speed of the shaft based on signals provided by the magnetic field sensor when it senses a magnetic field generated by at least two magnets of the plurality of magnets as the shaft pivots in one direction.