Electrical device for sensing temperature of hot spot of a switching device

Abstract

Embodiments of the present disclosure relate to an electrical device for sensing a temperature of a hot spot of a switchgear. The electrical device includes an energy harvester, a first interface terminal, and a wireless circuit. The energy harvester is configured to harvest energy of the switchgear. The first interface terminal is configured to interface with a second interface terminal of the switchgear to receive a first temperature signal from the second interface terminal. The first temperature signal is indicative of a first temperature sensed by a first temperature sensor in the switchgear. The wireless circuit is coupled to the energy harvester and the first interface terminal and is configured to wirelessly transmit a first wireless signal with power provided from the energy harvester. The first wireless signal is associated with the first temperature signal. By utilizing embodiments herein, the electrical device can be replaced without powering off the switchgear.

Description

TECHNICAL FIELD

[0001] Example embodiments of the present disclosure generally relate to temperature sensing technology, and more particularly, to an electrical device, a circuit breaker, and a switchgear for sensing temperature of hotspots of the switchgear. BACKGROUND

[0002] Electrical devices, such as medium voltage (MV) switchgears, are widely deployed in power grids. The switchgears can generate significant heat during operation, causing temperature in the switchgears to increase significantly. The temperature increase can cause potential serious damage. As such, various locations in the switchgears that can accumulate heat and / or are affected by heat need to be monitored. These locations are often referred to as hotspots.

[0003] Conventionally, wireless temperature sensors are applied and installed near the hotspots to handle the MV switchgears. The wireless circuit including the temperature sensors has limited lifetime, failure possibility, or upgrade requirement for various reasons, and replacement of the wireless circuit needs to be considered. However, in the case of a busbar outage of the entire panel, for example, replacement of the wireless circuit at the busbar joint can extend the outage area and can lose cost effectiveness. Therefore, there is a need for an improved method for monitoring temperature of hotspots in a switchgear. SUMMARY

[0004] Example embodiments of the present disclosure propose a solution of an electrical device for sensing temperature of hotspots in a switchgear.

[0005] In a first aspect, an electrical device is provided. The electrical device includes an energy harvester, a first interface terminal, and a wireless circuit. The energy harvester is configured to harvest energy of a switchgear. The first interface terminal is configured to interface with a second interface terminal of the switchgear to receive a first temperature signal from the second interface terminal. The first temperature signal is indicative of a first temperature sensed by a first temperature sensor in the switchgear. The wireless circuit is coupled to the energy harvester and the first interface terminal, and is configured to wirelessly transmit a first wireless signal with power provided from the energy harvester. The first wireless signal is associated with the first temperature signal.

[0006] In a second aspect, a circuit breaker is provided. The circuit breaker includes a first assembly for a first phase. The first assembly for the first phase includes a first arm, a first energy harvester, a first interface terminal, and a first wireless circuit. The first energy harvester is disposed on a side surface of the first arm and is configured to harvest energy of a switchgear. The first interface terminal is configured to interface with a second interface terminal of the switchgear to receive a first temperature signal from the second interface terminal. The first temperature signal is indicative of a first temperature sensed by a first temperature sensor in the switchgear. The first wireless circuit is disposed on the side surface of the first arm. The first wireless circuit is coupled to the first energy harvester and the first interface terminal and is configured to wirelessly transmit a first wireless signal with power provided from the first energy harvester. The first wireless signal is associated with the first temperature signal.

[0007] In a third aspect, a switchgear including the circuit breaker of the second aspect is provided.

[0008] In a fourth aspect, a method for manufacturing an electronic device is provided. The method includes providing an energy harvester, providing a first interface terminal, and providing a wireless circuit. The energy harvester is configured to harvest energy of a switchgear. The first interface terminal is configured to interface with a second interface terminal of the switchgear to receive a first temperature signal from the second interface terminal, the first temperature signal being indicative of a first temperature sensed by a first temperature sensor in the switchgear. The wireless circuit is coupled to the energy harvester and the first interface terminal and is configured to wirelessly transmit a first wireless signal with power provided from the energy harvester. The first wireless signal is associated with the first temperature signal.

[0009] According to embodiments of the present disclosure, according to the solution of embodiments of the present disclosure, temperature monitoring of hot spots in a switchgear and replacement of sensors without powering off the switchgear are achieved. BRIEF DESCRIPTION OF DRAWINGS

[0010] The above and other objects, features and advantages of the example embodiments disclosed herein will become more apparent from the following detailed description thereof taken in conjunction with the accompanying drawings. In the drawings, several example embodiments disclosed herein are illustrated by way of example and not limitation in the figures, in which:

[0011] Figure 1 A block diagram illustrating an example environment in which some example embodiments of the present disclosure are implemented is shown;

[0012] Figure 2 A block diagram illustrating an electrical device in accordance with some example embodiments of the present disclosure is shown;

[0013] Figure 3 A block diagram illustrating a portion of a circuit breaker connected to a portion of a switchgear in accordance with some example embodiments of the present disclosure is shown;

[0014] Figure 4 A flowchart of a method for manufacturing an electrical device according to some example embodiments of the present disclosure is shown.

[0015] Throughout the drawings, identical or similarly identified reference numerals are used to designate identical or similar parts. DETAILED DESCRIPTION

[0016] The subject matter described herein will now be discussed with reference to several example embodiments. These embodiments are discussed in order to provide a better understanding of the subject matter described herein, and to enable a person skilled in the art to more readily make and use the subject matter described herein, but are not intended to limit the scope of the subject matter described herein.

[0017] The terms "comprises" or "comprising" and variations thereof shall be interpreted as open terms, meaning "including, but not limited to." The term "or" shall be interpreted as "and / or" unless otherwise indicated. The term "based on" shall be interpreted as "based, at least in part, on." The term "operatively" refers to a function, action, motion, or state that can be achieved through an operation caused by a user or external agency. The terms "one embodiment" and "an embodiment" shall be understood to refer to at least one embodiment. The term "another embodiment" shall be understood to refer to at least one embodiment.

[0018] Unless otherwise specified or limited, the terms "mount," "connected," "supported," and "coupled" and variations thereof broadly include direct and indirect mounting, connecting, supporting, and coupling. Further, "connected" and "coupled" are not restricted to physical or mechanical connections or couplings. In the description below, like or similar parts or elements are designated by like reference numerals or characters throughout the description. Other explicit and implicit definitions can be included below.

[0019] As mentioned above, conventional methods for monitoring hot spot temperatures in MV switchgear often require that the switchgear or at least a portion of the switchgear (e.g., a busbar) needs to be de-energized or shut down in case the sensing device in the switchgear needs to be replaced. This can expand the de-energized area and correspondingly lose cost economy.

[0020] In some embodiments, an improved solution for temperature sensing is presented. By separating the circuitry for temperature sensing at different locations, there is no need to de-energize the switchgear. For example, a durable temperature sensor or temperature sensing probe can be provided in the switchgear, which can be used for a long service life without replacement. Other circuitry that can sometimes need to be replaced can be provided in an electrical device such as a circuit breaker. The electrical device can be separated or detached from the switchgear without de-energizing the switchgear.

[0021] Figure 1A block diagram of an example environment 100 implementing some example embodiments of the present disclosure is shown. The example environment 100 can include a switchgear 20 and an electrical device 10. In one embodiment, the electrical device 10 can be a circuit breaker. Although the electrical device 10 is described below with reference to a circuit breaker, this is for illustrative purposes only and does not imply any limitation on the scope of the present disclosure. Other electrical devices capable of being detached or disassembled from the switchgear without de-energizing the switchgear, such as circuit breakers, can also be applied.

[0022] In some embodiments, the electrical device 10 can include three phase units or assemblies 30, 50, and 70 for three phases. One of the three assemblies 30, 50, and 70 corresponds to one phase of the three phases, and the three assemblies 30, 50, and 70 can have substantially the same or similar configurations and operate in the same or similar manner. Alternatively, the electrical device 10 can include one or more phase units or assemblies for an electrical system including one or more phases. In one embodiment, the electrical device 10 can include one, two, or four phase units or assemblies, and the electrical system can be a single-phase, two-phase, or four-phase electrical system.

[0023] In one embodiment, the switchgear 20 includes a first busbar or cable 21 and a second busbar or cable 22. A first temperature sensor 24 is attached to a surface of the first busbar or cable 21. Alternatively, the first temperature sensor 24 is disposed on an inner surface of a tube 23 close to or adjacent to the first busbar 21, such that the first temperature sensor 24 can accurately sense the temperature of the first hot spot. In one embodiment, the first hot spot can be located at a connection between the first busbar 21 and the tube 23. The temperature sensor here can include one of a thermistor, a thermal integrated circuit chip, or a thermal coupler. Other durable temperature sensors that can be used for long term in the switchgear can also be applied.

[0024] Likewise, a second temperature sensor 26 is attached to a surface of the second busbar or cable 22. Alternatively, the second temperature sensor 26 is disposed on an inner surface of a tube 27 close to or adjacent to the second busbar 22, such that the second temperature sensor 26 can accurately sense the temperature of the second hot spot. In one embodiment, the second hot spot can be located at a connection between the second busbar 22 and the tube 27. The temperature distribution in the switchgear 20 can be variable from one place to another. Therefore, the accuracy of temperature sensing is important for timely detection of hot spot failure. By providing a temperature sensor at or near the hot spot, the overheating or failure of the hot spot can be timely and accurately detected.

[0025] In one embodiment, the tubes 23 and 27 are copper tubes that are at the same potential. Other tubes or structures at the same potential can also be applied. The first wire connection 25 (e.g., copper wire) couples the first temperature sensor 24 to the electrical device 10 via a terminal, which will be described in detail below. Likewise, the second wire connection 28 (e.g., copper wire) couples the second temperature sensor 26 to the electrical device 10 via another terminal. Although copper wires are shown, this is for illustration only and does not imply any limitation on the scope of the disclosure. Other wire or connection means can also be applied. It should be appreciated that six connections and terminals should be provided for a three-phase situation.

[0026] In the event that the electrical device 10 needs to be repaired or replaced, the electrical device 10 can be pulled out of the switchgear 20. Since the electrical device 10 is a circuit breaker in one embodiment, the electrical device 10 trips when there is a fault (e.g., short circuit) in the switchgear 20. During normal operation of the switchgear 20, the electrical device 10 is free to be separated or pulled out of the switchgear 20. Thus, if there is some problem with the temperature sensing circuitry within the electrical device 10 and it can need to be repaired or replaced, the electrical device 10 can be separated from the switchgear 20 without de-energizing the switchgear 20. In the event that the circuitry is repaired or replaced, the electrical device 10 can be assembled into the switchgear 20. By doing so, hot spots of the switchgear 20 can be continuously monitored without taking the switchgear 20 off-line. In another embodiment, the electrical device 10 is a disconnector for electrical isolation.

[0027] Figure 2 A block diagram of an electrical device 30 implementing some example embodiments according to the disclosure is shown. In one embodiment, the electrical device 30 is an assembly for one phase of a three-phase. The electrical device 30 includes an energy harvester 32, a wireless circuit 34, and a second sensor 36. In some embodiments, the second sensor 36 can be omitted.

[0028] The energy harvester 32 is configured to harvest energy of the switchgear 20. In one embodiment, the energy harvester 32 is a current transformer configured to convert energy of an alternating magnetic field within the switchgear 20 to electrical power. Other means to collect energy within the switchgear 20 can also be applied. For example, a thermoelectric generator or an electric field harvester can be applied.

[0029] The energy harvester 32 provides converted electrical power to the wireless circuit 34 so that the wireless circuit 34 can operate using power from the energy harvester 32. In one embodiment, the wireless circuit 34 can include a power management circuit, a controller such as a micro control unit (MCU), a radio frequency circuit configured to wirelessly transmit a signal indicative of temperature. The power management circuit or the MCU can process the temperature signal sensed by the temperature sensor so that the temperature signal can be converted into a wireless signal suitable for wireless transmission.

[0030] The electrical device 30 can include a first interface terminal 13 configured to interface with the second interface 11 of the switch device 20. The first interface terminal 13 is electrically coupled to the wireless circuit 34 so that the wireless circuit 34 can receive the temperature signal sensed by the first sensor 24 in the switch device 20 via the first interface terminal 11 and the second interface terminal 13. In one embodiment, the first interface terminal 11 and the second interface terminal 13 are connected in the case where the electrical device 30 is plugged or assembled to the switch device 20. The first interface terminal 11 and the second interface terminal 13 are disconnected in the case where the electrical device 30 is pulled out or detached from the switch device 20. In one embodiment, the first interface terminal 11 and the second interface terminal 13 can be one of a plug, a contact finger, or a pogo pin.

[0031] The energy harvester 32 and the wireless circuit 34 can sometimes need maintenance or replacement. By separating the energy harvester 32 and the wireless circuit 34 from the durable first sensor 24 disposed in the switch device 20, the temperature sensing circuit can be replaced or repaired as needed as it is disposed in the detachable circuit 30. In the case where the electrical device 30 is removed from the switch device 20, the switch device 20 can operate normally without power outage or downtime.

[0032] Although only the first sensor 24 and the corresponding interface terminals 11 and 13 are shown in Figure 2 for illustrative purposes only and do not imply any limitation on the scope of the present disclosure. For example, it can be appreciated that in an embodiment, if the electrical device 30 is a circuit breaker, there is another temperature sensor, e.g., the temperature sensor 26, and corresponding interfaces and connection wires for sensing another hot spot in the switch device.

[0033] In one embodiment, the electrical device 30 further comprises a second temperature sensor 36. In one embodiment, the second temperature sensor 36 can be one of a thermistor, a thermal integrated circuit chip, or a thermal coupler, and can be disposed at a location in the electrical device 30. In the case that the electrical device 30 is a circuit breaker, the second temperature sensor 36 can be disposed adjacent to the wireless circuit 34 on a side surface of the arm 41. The second temperature sensor 36 generates a second temperature signal indicative of a second temperature of a location proximate to the movable contact of the circuit breaker.

[0034] Figure 3 A block diagram of a portion of a circuit breaker connecting a portion of a switchgear is shown in accordance with some example embodiments of the present disclosure. The circuit breaker can comprise three circuit breaking assemblies for three phases. For each phase, there are two arms that engage with two terminals of a phase line, such that the circuit breaking assembly can be coupled between the two terminals of the phase line. For brevity, Figure 3 Only one arm 41 of the circuit breaking assembly of the circuit breaker is shown in FIG. 1. It can be appreciated that the other arm of the circuit breaking assembly can have a similar corresponding configuration, and the other two phases can have similar configurations.

[0035] The switchgear can comprise various hot spots, such as a hot spot between the first bus bar 21 and the tube 23 and a hot spot between the second bus bar 22 and the tube 27. The first temperature sensor 24 is attached to a surface of the first bus bar 21. Alternatively, the first temperature sensor 24 is disposed on an inner surface of the tube 23, close to or adjacent to the first bus bar 21, such that the first temperature sensor 24 can accurately sense the temperature of the first hot spot. The temperature sensor here can comprise one of a thermistor, a thermal integrated circuit chip, or a thermal coupler. Other durable temperature sensors that can be used for long service life can be applied.

[0036] The first temperature sensor 24 is connected to the second interface terminal 11 by a wire 25. The wire 25 is disposed within the equipotential tube. In one embodiment, the tube is a copper tube, and the wire 25 is a copper wire. Alternatively, other masking assemblies of different shapes and materials are possible for the tube 23, and other materials for the wire 25 are also possible. In one embodiment, the second interface terminal 11 or the first interface terminal 13 comprises one of a plug, a contact finger, or a pogo pin.

[0037] The arm 41 is fixed to the tube 23 when the circuit breaker is in place. For example, the arm 41 is fixed to the tube 23 when at least a portion of the circuit breaker is inserted into the switchgear 20 to a suggested position. Further, in this case, the first interface terminal 13 is automatically connected with the second interface terminal 11. The first interface terminal 13 is electrically coupled to the wireless circuit 34 by a wire 43.

[0038] The current transformer 42 surrounds the arm 41 at a side surface of the arm 41 and is electrically coupled to the wireless circuit 34. The wireless circuit 34 is also electrically coupled to a second temperature sensor 36, which can be omitted in some embodiments. The wireless circuit 34 and the second temperature sensor 36 can be disposed at the side surface of the arm 41. Although they are shown as being disposed on the side surface of the arm 41, this is for illustrative purposes only and does not imply any limitation on the scope of the present disclosure. They can be disposed at other locations, such as the inner surface of the arm 41.

[0039] Although the arm 41 is shown in Figure 3 as a first circuit breaking assembly for a first phase, it should be understood that the circuit breaking assembly can have another arm with the same configuration, including a wireless circuit, an energy harvester, interface terminals, and an optional second sensor, etc. Thus, it can be understood that the components of the other half of the first circuit breaking assembly and their relationships are the same as the half of the first circuit breaking assembly shown in Figure 3 .

[0040] Further, it should be understood that the circuit breaker can have a second circuit breaking assembly for a second phase and a third circuit breaking assembly for a third phase. In one embodiment, the second circuit breaking assembly and the third circuit breaking assembly can have the same configuration as the first circuit breaking assembly. Thus, it can be understood that the components and the relationships between the components are the same as in the first circuit breaking assembly.

[0041] Figure 4 A flowchart of a method 400 for manufacturing an electrical device according to some example embodiments of the present disclosure is shown. In one embodiment, the electrical device can be the electrical device 10 or 30 of Figures 1-3 . Thus, the features described with reference to Figure 1 -FIG. can be applied to the method 400. Figure 3

[0042] In 402, an energy harvester is provided. The energy harvester is configured to harvest energy of a switching device. In 404, a first interface terminal is provided. The first interface terminal is configured to interface with a second interface terminal of the switching device to receive a first temperature signal from the second interface terminal, the first temperature signal being indicative of a first temperature sensed by a first temperature sensor in the switching device.

[0043] In 406, a wireless circuit is provided. The wireless circuit is coupled to the energy harvester and the first interface terminal and is configured to wirelessly transmit a first wireless signal with power provided from the energy harvester. The first wireless signal is associated with the first temperature signal. In the following, some example implementations of the subject matter herein will be listed.

[0044] ​Item 1. An electrical device is provided, the electrical device comprising an energy harvester configured to harvest energy of a switching device; a first interface terminal configured to interface with a second interface terminal of the switching device to receive a first temperature signal from the second interface terminal, the first temperature signal indicative of a first temperature sensed by a first temperature sensor in the switching device; and a wireless circuit coupled to the energy harvester and the first interface terminal and configured to wirelessly transmit a first wireless signal associated with the first temperature signal using power provided from the energy harvester.

[0045] Item 2. The electrical device of item 1, further comprising a second temperature sensor configured to generate a second temperature signal indicative of a second temperature of a location in the electrical device; wherein the wireless circuit is coupled to the second temperature sensor to wirelessly transmit a second wireless signal associated with the second temperature signal.

[0046] Item 3. The electrical device of item 1 or 2, further comprising an arm of a circuit breaker, wherein the energy harvester comprises a current transformer at a side surface of the arm, the current transformer configured to convert energy of an electric field inside the switching device to power provided to the energy harvester.

[0047] Item 4. The electrical device of any of items 1-3, wherein the wireless circuit is disposed at the side surface of the arm adjacent to the current transformer.

[0048] Item 5. The electrical device of any of items 1-4, further comprising a second temperature sensor adjacent to the wireless circuit at the side surface of the wall, the second temperature sensor configured to generate a second temperature signal indicative of a second temperature of a location proximate to a movable contact of the circuit breaker.

[0049] Item 6. The electrical device of any of items 1-5, further comprising a first temperature sensor adapted to be disposed at or proximate to a bus bar in the switching device and coupled to the second interface terminal by a connection wire in an equipotential tube in the switching device.

[0050] Item 7. The electrical device of any of items 1-6, wherein the first interface terminal comprises one of a plug, a contact finger, or a pogo pin; and the first temperature sensor comprises one of a thermistor, a thermal integrated circuit chip, or a thermal coupler.

[0051] Item 8. A circuit breaker is provided, comprising a first assembly for a first phase. The first assembly includes a first arm; a first energy harvester on a side surface of the first arm, the first energy harvester configured to harvest energy of a switching device; a first interface terminal configured to interface with a second interface terminal of the switching device to receive a first temperature signal from the second interface terminal, the first temperature signal indicative of a first temperature sensed by a first temperature sensor in the switching device; and a first wireless circuit on the side surface of the first arm, the first wireless circuit coupled to the first energy harvester and the first interface terminal, and configured to wirelessly transmit a first wireless signal using power provided from the first energy harvester, the first wireless signal associated with the first temperature signal.

[0052] Item 9. The circuit breaker of item 8, wherein the first assembly further includes a second arm; a second energy harvester on a side surface of the second arm, the second energy harvester configured to harvest energy of the switching device; a third interface terminal configured to interface with a fourth interface terminal of the switching device to receive a third temperature signal from the fourth interface terminal, the third temperature signal indicative of a third temperature sensed by a third temperature sensor in the switching device; and a second wireless circuit on the side surface of the second arm, the second wireless circuit coupled to the second energy harvester and the third interface terminal, and configured to wirelessly transmit a third wireless signal using power provided from the second energy harvester, the third wireless signal associated with the third temperature signal.

[0053] Item 10. The circuit breaker of any of items 8-9, further comprising: a second assembly for a second phase, the second assembly including a fifth interface terminal configured to interface with a sixth interface terminal of the switching device to receive a fifth temperature signal from the sixth interface terminal, the fifth temperature signal indicative of a fifth temperature sensed by a fifth temperature sensor in the switching device; and a seventh interface terminal configured to interface with an eighth interface terminal of the switching device to receive a seventh temperature signal from the eighth interface terminal, the seventh temperature signal indicative of a seventh temperature sensed by a seventh temperature sensor in the switching device; and a third assembly for a third phase, the third assembly including: a ninth interface terminal configured to interface with a tenth interface terminal of the switching device to receive a ninth temperature signal from the tenth interface terminal, the ninth temperature signal indicative of a ninth temperature sensed by a ninth temperature sensor in the switching device; and an eleventh interface terminal configured to interface with a twelfth interface terminal of the switching device to receive an eleventh temperature signal from the twelfth interface terminal, the eleventh temperature signal indicative of an eleventh temperature sensed by an eleventh temperature sensor in the switching device.

[0054] Item 11. The circuit breaker of any of items 8-10, wherein the first assembly for the first phase further comprises a second temperature sensor adjacent to the first wireless circuit at the side surface of the first arm, the second temperature sensor configured to generate a second temperature signal indicative of a second temperature of a location proximate to the movable contact of the circuit breaker.

[0055] Item 12. The circuit breaker of any of items 8-11, further comprising a first temperature sensor adapted to be disposed at or proximate to a bus in the switching device and coupled to the second interface terminal by a connecting wire in an equipotential tube in the switching device.

[0056] Item 13. The circuit breaker of any of items 8-12, wherein the first interface terminal comprises one of a plug, a contact finger, or a pogo pin; and the first temperature sensor comprises one of a thermistor, a thermal integrated circuit chip, or a thermal coupler.

[0057] Item 14. A switching device is provided comprising the circuit breaker of any of items 8-13.

[0058] Item 15. A method for manufacturing an electronic device is provided. The method comprises providing an energy harvester configured to harvest energy of a switching device; providing a first interface terminal configured to interface with a second interface terminal of the switching device to receive a first temperature signal from the second interface terminal, the first temperature signal indicative of a first temperature sensed by a first temperature sensor in the switching device; and providing a wireless circuit coupled to the energy harvester and the first interface terminal and configured to wirelessly transmit a first wireless signal with power provided from the energy harvester, the first wireless signal associated with the first temperature signal.

[0059] Moreover, while operations may be described as being performed in a certain order, this should not be understood as requiring that particular order, or that all operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing can be advantageous. Likewise, while a number of specific implementation details have been included for the purpose of providing a thorough description of certain embodiments, these should not be construed as limiting the scope of the disclosure, but rather as merely providing an example of individual implementations. Certain features that are described in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub-combination. Although the foregoing has been described in some detail for purposes of clarity, it is understood that certain changes and modifications will be apparent to those skilled in the art and can be made without departing from the principles and scope of the disclosure, which is to be limited only by the scope of the appended claims.

[0060] Although the subject matter has been described in language specific to structural features and / or methodological acts, it is to be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

1. An electrical device (30) adapted to be removably coupled to a switchgear (20) and comprising: an energy harvester (32) configured to harvest energy of the switchgear (20); a first interface terminal (13) configured to interface with a second interface terminal (11) of the switchgear (20) to receive a first temperature signal from the second interface terminal, the switchgear (20) including a first temperature sensor (24), the first temperature signal indicative of a first temperature sensed by the first temperature sensor (24) in the switchgear (20); and a wireless circuit (34) coupled to the energy harvester (32) and the first interface terminal (13) and configured to wirelessly transmit a first wireless signal associated with the first temperature signal using power provided from the energy harvester (32).

2. The electrical device (30) of claim 1, further comprising a second temperature sensor (36) configured to generate a second temperature signal indicative of a second temperature of a location in the electrical device; wherein the wireless circuit (34) is coupled to the second temperature sensor (36) to wirelessly transmit a second wireless signal associated with the second temperature signal.

3. The electrical device (30) of claim 1, further comprising an arm (41) of a circuit breaker, wherein the energy harvester (32) includes a current transformer (42) at a side surface of the arm (41), the current transformer (42) configured to convert energy of an electromagnetic field inside the switchgear (20) to the power provided to the energy harvester (32).

4. The electrical device (30) of claim 3, wherein the wireless circuit (34) is disposed adjacent to the current transformer (42) at the side surface of the arm (41).

5. The electrical device (30) of claim 4, further comprising a second temperature sensor (36) adjacent to the wireless circuit (34) at the side surface of the arm (41), the second temperature sensor (36) configured to generate a second temperature signal indicative of a second temperature of a location proximate to a movable contact of the circuit breaker.

6. The electrical device (30) of claim 1, wherein the first temperature sensor is adapted to be disposed at or proximate to a bus in the switchgear (20) and coupled to the second interface terminal (11) by a connecting wire in an equipotential tube in the switchgear (20).

7. The electrical device (30) of claim 1, wherein the first interface terminal (13) comprises one of a plug, a contact finger, or a pogo pin; and the first temperature sensor comprises one of a thermistor, a thermal integrated circuit chip, or a thermal coupler.

8. A circuit breaker adapted to be removably coupled to a switchgear (20) and comprising: ​ A first assembly for a first phase, comprising: a first arm; a first energy harvester (32) on a side surface of the first arm, the first energy harvester (32) configured to harvest energy of the switch device (20); a first interface terminal (13) configured to interface with a second interface terminal (11) of the switch device (20) to receive a first temperature signal from the second interface terminal (11), the switch device (20) comprising a first temperature sensor (24), the first temperature signal indicative of a first temperature sensed by the first temperature sensor (24) in the switch device (20); and a first wireless circuit (34) on the side surface of the first arm, the first wireless circuit (34) coupled to the first energy harvester (32) and the first interface terminal (13) and configured to wirelessly transmit a first wireless signal associated with the first temperature signal using power provided from the first energy harvester (32).

9. The circuit breaker of claim 8, wherein the first assembly further comprises: a second arm; a second energy harvester on a side surface of the second arm, the second energy harvester configured to harvest energy of the switch device (20); a third interface terminal configured to interface with a fourth interface terminal of the switch device (20) to receive a third temperature signal from the fourth interface terminal, the switch device (20) comprising a third temperature sensor, the third temperature signal indicative of a third temperature sensed by the third temperature sensor in the switch device (20); and a second wireless circuit on the side surface of the second arm, the second wireless circuit coupled to the second energy harvester and the third interface terminal and configured to wirelessly transmit a third wireless signal associated with the third temperature signal using power provided from the second energy harvester (32).

10. The circuit breaker of claim 9, further comprising: a second assembly for a second phase, comprising a fifth interface terminal configured to interface with a sixth interface terminal of the switch device to receive a fifth temperature signal from the sixth interface terminal, the switch device (20) comprising a fifth temperature sensor, the fifth temperature signal indicative of a fifth temperature sensed by the fifth temperature sensor in the switch device (20); and a seventh interface terminal configured to interface with an eighth interface terminal of the switch device to receive a seventh temperature signal from the eighth interface terminal, the switch device (20) comprising a seventh temperature sensor, the seventh temperature signal indicative of a seventh temperature sensed by the seventh temperature sensor in the switch device (20); and a third assembly for a third phase, comprising: ​ ​ ​ a ninth interface terminal configured to interface with a tenth interface terminal of the switchgear to receive a ninth temperature signal from the tenth interface terminal, the switchgear (20) comprising a ninth temperature sensor, the ninth temperature signal being indicative of a ninth temperature sensed by the ninth temperature sensor in the switchgear (20); and an eleventh interface terminal configured to interface with a twelfth interface terminal of the switchgear to receive an eleventh temperature signal from the twelfth interface terminal, the switchgear (20) comprising an eleventh temperature sensor, the eleventh temperature signal being indicative of an eleventh temperature sensed by the eleventh temperature sensor in the switchgear (20).

11. The circuit breaker of claim 8, wherein the first assembly for the first phase further comprises a second temperature sensor adjacent to the first wireless circuit (34) at a side surface of the first arm (41), the second temperature sensor (36) being configured to generate a second temperature signal indicative of a second temperature of a location proximate to a movable contact of the circuit breaker.

12. The circuit breaker of claim 8, wherein the first temperature sensor is adapted to be disposed at or near a bus in the switchgear (20) and coupled to the second interface terminal (11) by a connecting wire in an equipotential tube in the switchgear (20).

13. The circuit breaker of claim 8, wherein the first interface terminal (13) comprises one of a plug, a contact finger, or a pogo pin; and the first temperature sensor comprises one of a thermistor, a thermal integrated circuit chip, or a thermal coupler.

14. An electrical system comprising: a switchgear (20), and the circuit breaker of any one of claims 8-13.

15. A method for manufacturing an electrical device adapted to be removably coupled to a switchgear (20), the method comprising: providing an energy harvester (32) configured to harvest energy of the switchgear (20); providing a first interface terminal (13) configured to interface with a second interface terminal (11) of the switchgear (20) to receive a first temperature signal from the second interface terminal, the switchgear (20) comprising a first temperature sensor (24), the first temperature signal being indicative of a first temperature sensed by the first temperature sensor (24) in the switchgear (20); and providing a wireless circuit (34) coupled to the energy harvester (32) and the first interface terminal (13) and configured to wirelessly transmit a first wireless signal utilizing power provided from the energy harvester (32), the first wireless signal being associated with the first temperature signal.

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