Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
  • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
  • G01R31/327—Testing of circuit interrupters, switches or circuit-breakers

Definitions

• Example embodiments of the present disclosure generally relate to a technology of temperature sensing and more particularly, to an electric device for sensing temperatures of hotspots of a switchgear, a circuit breaker and a switchgear.
• Electric apparatuses such as switchgears of middle voltage (MV)
• MV middle voltage
• the switchgears may generate significant heat during operation, causing a significantly increased temperature in the switchgear.
• the increased temperature may cause potential severe damages.
• various locations that may accumulate heat and/or be affected by heat need to be monitored in the switchgear. These locations are generally called hotspots.
• wireless temperature sensors are applied and mounted near hotspots to take care of the MV switchgear.
• the wireless circuit comprising a temperature sensor has limited lifetime, failure possibility or upgrade requirement for various reasons, and replacement for the wireless circuit needs to be considered.
• replacement of the wireless circuit for example at a bus bar joint, is conducted in case that the bus bar is de-energized for a whole panel, which may extend power outage area, and may cost economy lost.
• an improved approach for monitoring temperatures of hotspots in a switchgear is desired.
• Example embodiments of the present disclosure propose a solution of electric device for sensing a temperature of a hotspot in a switchgear.
• an electric device comprising 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 indicates 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 configured to wirelessly transmit a first wireless signal with power supplied from the energy harvester.
• the first wireless signal is associated with the first temperature signal.
• the circuit breaker comprises a first assembly for a first phase.
• the first assembly for a first phase comprises a first arm, a first energy harvester, a first interface terminal and a first wireless circuit.
• the first energy harvester is provided on a lateral surface of the first arm, and 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 indicates a first temperature sensed by a first temperature sensor in the switchgear.
• the first wireless circuit is provided on the lateral surface of the first arm.
• the first wireless circuit is coupled to the first energy harvester and the first interface terminal, and configured to wirelessly transmit a first wireless signal with power supplied from the first energy harvester.
• the first wireless signal being associated with the first temperature signal.
• a switchgear comprising the circuit breaker of the second aspect.
• a method for manufacturing an electric device comprises 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 indicating 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 configured to wirelessly transmit a first wireless signal with power supplied from the energy harvester.
• the first wireless signal is associated with the first temperature signal.
• the solution according to embodiments of the present disclosure is to achieve temperature monitoring of hotspots in a switchgear and replacement of sensors without de-energization for the switchgear.
• Fig. 1 illustrates a block diagram of an example environment of implementing some example embodiments of the present disclosure
• Fig. 2 illustrates a block diagram implementing an electric device in accordance with some example embodiments of the present disclosure
• Fig. 3 illustrates a block diagram illustrating a part of a circuit breaker connecting a part of a switchgear in accordance with some example embodiments of the present disclosure
• Fig. 4 illustrates a flowchart of a method for manufacturing an electric device in accordance with some example embodiments of the present disclosure.
• the term “comprises” or “includes” and its variants are to be read as open terms that mean “includes, but is not limited to. ”
• the term “or” is to be read as “and/or” unless the context clearly indicates otherwise.
• the term “based on” is to be read as “based at least in part on. ”
• the term “being operable to” is to mean a function, an action, a motion or a state can be achieved by an operation induced by a user or an external mechanism.
• the term “one embodiment” and “an embodiment” are to be read as “at least one embodiment. ”
• the term “another embodiment” is to be read as “at least one other embodiment. ”
• it may sense temperatures of hotspots in a switchgear without de-energization for the switchgear.
• a durable temperature sensor or temperature sensing probe which may serve for a long life time without replacement, may be provided in the switchgear.
• Other circuitries that may need replacement from time to time, may be provided in an electric device, such as a circuit breaker. The electric device may be disassembled or detached from the switchgear without de-energization for the switchgear.
• Fig. 1 illustrates a block diagram of an example environment 100 of implementing some example embodiments of the present disclosure.
• the example environment 100 may comprise a switchgear 20 and an electric device 10.
• the electric device 10 may be a circuit breaker.
• the electric device 10 is described with reference to a circuit breaker hereinafter, this is only for the purpose of illustration without suggesting any limitation as to the scope of the disclosure.
• Other electric devices, such as disconnectors, capable of being disassembled or detached from the switchgear without de-energization for the switchgear may be applied as well.
• the electric device 10 may comprise three phase units or assemblies 30, 50 and 70 for three phases.
• One of the three assemblies 30, 50 and 70 corresponds to one of the three phases, and the three assemblies 30, 50 and 70 may have substantially the same or similar configurations and operate in a same or similar manner.
• the electric device 10 may comprise one or more phase unit or assembly for an electric system comprising one or more phase.
• the electric device 10 may comprise one, two or four phase unit or assembly, and the electric system may be a one-phase, two-phases or four-phases electric system.
• the switchgear 20 comprises a first bus bar or cable 21 and a second bus bar or cable 22 in an embodiment.
• a first temperature sensor 24 is attached to a surface of the first bus bar 21.
• the first temperature sensor 24 is provided on an inner surface of a tube 23 near or adjacent to the first bus bar 21, such that the first temperature sensor 24 may accurately sense a temperature of a first hotspot.
• the first hotspot may be located at the connection between the first bus bar 21 and the tube 23.
• Temperature sensors herein may comprise one of a thermal resistor, a thermal integrated circuit chip, or a thermal coupler. Other durable temperature sensors that may serve for a long life time in the switchgear may be applied as well.
• a second temperature sensor 26 is attached to a surface of the second bus bar or cable 22.
• the second temperature sensor 26 is provided on an inner surface of a tube 27 near or adjacent to the second bus bar 22, such that the second temperature sensor 26 may accurately sense a temperature of a second hotspot.
• the second hotspot may be located at the connection between the second bus bar 22 and the tube 27.
• Temperature distribution in the switchgear 20 may be variable from place to place. Thus, accuracy for temperature sensing is important for timely detection of failure of hotspot. By providing temperature sensors at or near the hotspots, it may timely and accurately detect overheat or failure of the hotspots.
• the tubes 23 and 27 are copper tubes of equal potential, respectively. Other tubes or structures of equal potential may also be applied.
• a first wire connection 25, for example a copper wire couples the first temperature sensor 24 to the electric device 10 via an interface, which will be described below specifically.
• a second wire connection 28, for example a copper wire couples the second temperature sensor 26 to the electric device 10 via another interface.
• copper wires are illustrated, this is only for illustration without suggesting any limitation to scopes of the present disclosure.
• Other conductive wires or connection devices may be applied as well. It should be understood that six connection wires and interfaces should be provided for the scenario of three phases.
• the electric device 10 can be pulled out of the switchgear 20, in case it needs to be repaired or replaced. Since the electric device 10 is a circuit breaker in an embodiment, it operates when there is a failure, such as a short-circuit, in the switchgear 20. During normal operation of the switchgear 20, the electric device 10 can be freely detached from or pulled out of the switchgear 20. Thus, if the temperature sensing circuitry inside the electric device 10 has some problem and may needs to be repaired or replaced, the electric device 10 can be separated from the switchgear 20, without de-energization of the switchgear 20. In case the circuitry is fixed or replaced, the electric device 10 may assembled into the switchgear 20. By doing so, the hotspots of the switchgear 20 can be continuously monitored without powering off the switchgear 20. In another embodiment, the electric device 10 is a disconnector for electrical isolation.
• Fig. 2 illustrates a block diagram implementing an electric device 30 in accordance with some example embodiments of the present disclosure.
• the electric device 30 is an assembly for one of the three phases in an embodiment.
• the electric device 30 comprises an energy harvester 32, a wireless circuit 34 and a second sensor 36.
• the second sensor 36 may be omitted.
• the energy harvester 32 is configured to harvest energy of a switchgear 20.
• the energy harvester 32 is a current transformer configured to transform energy of an ac magnetic field inside the switchgear 20 into electrical power.
• Other devices may be applied to harvest energy inside the switchgear 20 as well. For example, a thermoelectric generator or an electric field harvester may be applied to convert heat into electricity.
• the energy harvester 32 provides the transformed electrical power to the wireless circuit 34, such that the wireless circuit 34 may operate with the power from the energy harvester 32.
• the wireless circuit 34 may comprise a power management circuit, a controller such as a micro controlling unit (MCU) , a radio frequency circuit configured to wirelessly transmit signals indicating the temperatures.
• the power management circuit or the MCU may process the temperature signal sensed by temperature sensors, such that the temperature signals may be converted into wireless signals suitable for wireless transmitting.
• the electric device 30 may comprise a first interface terminal 13 configured to interface with a second interface 11 of the switchgear 20.
• the first interface terminal 13 is electrically coupled to the wireless circuit 34, such that the wireless circuit 34 may receive the temperature signal sensed by the first sensor 24 in the switchgear 20 via the first and second interface terminals 11 and 13.
• the first and second interface terminals 11 and 13 are automatically connected. While in case that the electric device 30 is pulled out of or disassembled from the switchgear 20, the first and second interface terminals 11 and 13 are automatically disconnected.
• the first and second interface terminals 11 and 13 may be one of a plug, a contact finger, or a pogopin.
• the energy harvester 32 and the wireless circuit 34 may require maintenance or replacement from time to time.
• the temperature sensing circuit may be replaced or repaired as needed, since it is provided in the detachable electric circuit 30.
• the switchgear 20 may operate normally without powering off or de-energization.
• first sensor 24 and the corresponding interface terminals 11 and 13 are illustrated in Fig. 2, it is only for the purpose of illustration without suggesting any limitation to the scopes of the present disclosure.
• another temperature sensor for example the temperature sensor 26, and the corresponding interfaces and connection wires for sensing another hotspot in the switchgear, if the electric device 30 is a circuit breaker in an embodiment.
• the electric device 30 further comprise a second temperature sensor 36.
• the second temperature sensor 36 may be one of a thermal resistor, a thermal integrated circuit chip, or a thermal coupler, and may be provided at a location in the electric device 30 in an embodiment.
• the second temperature sensor 36 may be provided adjacent to the wireless circuit 34 at a lateral surface of arm 41.
• the second temperature sensor 36 generates a second temperature signal indicating a second temperature of the location near a movable contact of the circuit breaker.
• Fig. 3 illustrates a block diagram illustrating a part of a circuit breaker connecting a part of a switchgear in accordance with some example embodiments of the present disclosure.
• the circuit breaker may comprise three circuit breaking assemblies for the three phases. For each phase, there are two arms to engage with the two terminals of a phase line, such that the circuit breaking assembly may be coupled between the two terminals of the phase line.
• only one arm 41 of the circuit breaking assembly of the circuit breaker is shown in Fig. 3. It could be understood that the other arm of the circuit breaking assembly may have a similar corresponding configuration, and the other two phases may have similar configuration.
• the switchgear may comprise various hotspots, such as the hotspot between the first bus bar 21 and the tube 23 and the hotspot 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.
• the first temperature sensor 24 is provided on an inner surface of a tube 23 near or adjacent to the first bus bar t 21, such that the first temperature sensor 24 may accurately sense a temperature of the first hotspot.
• Temperature sensors herein may comprise one of a thermal resistor, a thermal integrated circuit chip, or a thermal coupler. Other durable temperature sensors that may serve for a long life time may be applied.
• the first temperature sensor 24 is connected to the second interface terminal 11 via a conductive wire 25.
• the conductive wire 25 is provided inside a tube of equal potential.
• the tube is a copper tube, and the conductive wire 25 is copper wire.
• the second interface terminal 11 or the first interface terminal 13 comprises one of a plug, a contact finger, or a pogopin.
• the arm 41 is fixed to the tube 23 when the circuit breaker is in place.
• the arm 41 is fixed to the tube 23 when at least a part of the circuit breaker is inserted into the switchgear 20 to a propose position.
• the first interface terminal 13 is automatically connected with the second interface terminal 11 in this case.
• the first interface terminal 13 is electrically coupled to the wireless circuit 34 with a conductive wire 43.
• the current transformer 42 surrounds the arm 41 at the lateral surface of the arm 41, and is electrically coupled to the wireless circuit 34.
• the wireless circuit 34 is also electrically coupled to the second temperature sensor 36, which can be omitted in some embodiments.
• the wireless circuit 34 and the second temperature sensor 36 may be provided at the lateral surface of the arm 41. Although they are illustrated to be provided on the lateral surface of the arm 41, this is only for the purpose of illustration without suggesting any limitation as to the scope of the disclosure. They may be provided at other places, such as the inner surface of the arm 41.
• the arm 41 is illustrated in Fig. 3 for a first circuit breaking assembly for a first phase, it is understood that the circuit breaking assembly may have another arm with a same configuration comprising a wireless circuit, an energy harvester, an interface terminal and an optional second sensor.
• the components and their relationship of the other half of the first circuit breaking assembly are the same as the half of the first circuit breaking assembly as shown in Fig. 3.
• the circuit breaker may have a second circuit breaking assembly for a second phase, and a third circuit breaking assembly for a third phase.
• the second and third circuit breaking assemblies may have configurations same as the first circuit breaking assembly.
• the components and their relationship are the same as those in the first circuit breaking assembly.
• Fig. 4 illustrates a flowchart of a method 400 for manufacturing an electric device in accordance with some example embodiments of the present disclosure.
• the electric device may be the electric device 10 or 30 of Figs. 1-3 in an embodiment.
• the features described with reference to Figs. 1-3 may apply to the method 400 of Fig. 3.
• an energy harvester configured to harvest energy of a switchgear.
• a 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 indicating a first temperature sensed by a first temperature sensor in the switchgear.
• a wireless circuit is coupled to the energy harvester and the first interface terminal and configured to wirelessly transmit a first wireless signal with power supplied from the energy harvester.
• the first wireless signal is associated with the first temperature signal.
• an electric device comprising an energy harvester configured to harvest energy of a switchgear; a first interface terminal 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 indicating a first temperature sensed by a first temperature sensor in the switchgear; and a wireless circuit coupled to the energy harvester and the first interface terminal and configured to wirelessly transmit a first wireless signal with power supplied from the energy harvester, the first wireless signal being associated with the first temperature signal.
• Item 2 The electric device of Item 1, further comprising a second temperature sensor configured to generate a second temperature signal indicating a second temperature of a location in the electric device; wherein the wireless circuit is coupled to the second temperature sensor to wirelessly transmit a second wireless signal, the second wireless signal being associated with the second temperature signal.
• Item 3 The electric device of Item 1 or 2, further comprising an arm of a circuit breaker, wherein the energy harvester comprises a current transformer at a lateral surface of the arm, the current transformer configured to transform energy of electrical field inside the switchgear into the power supplied to the energy harvester.
• Item 4 The electric device of any of Items 1-3, wherein the wireless circuit is provided adjacent to the current transformer at the lateral surface of the arm.
• Item 5 The electric device of any of Items 1-4, further comprising a second temperature sensor adjacent to the wireless circuit at the lateral surface of arm, the second temperature sensor configured to generate a second temperature signal indicating a second temperature of a location near a movable contact of the circuit breaker.
• Item 6 The electric device of any of Items 1-5, further comprising the first temperature sensor adapted to be provided at or near a bus bar in the switchgear and coupled to the second interface terminal through a connection wire in a tube of equal potential in the switchgear.
• Item 7 The electric device of any of Items 1-6, wherein the first interface terminal comprises one of a plug, a contact finger, or a pogopin; and the first temperature sensor comprises one of a thermal resistor, a thermal integrated circuit chip, or a thermal coupler.
• circuit breaker comprising a first assembly for a first phase.
• the first assembly comprising a first arm; a first energy harvester on a lateral surface of the first arm, the first energy harvester configured to harvest energy of a switchgear; a first interface terminal 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 indicating a first temperature sensed by a first temperature sensor in the switchgear; and a first wireless circuit on the lateral 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 with power supplied from the first energy harvester, the first wireless signal being associated with the first temperature signal.
• Item 9 The circuit breaker of Item 8, wherein the first assembly further comprises a second arm; a second energy harvester on a lateral surface of the second arm, the second energy harvester configured to harvest energy of the switchgear; a third interface terminal configured to interface with a fourth interface terminal of the switchgear to receive a third temperature signal from the fourth interface terminal, the third temperature signal indicating a third temperature sensed by a third temperature sensor in the switchgear; and a second wireless circuit on the lateral 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 with power supplied from the second energy harvester, the third wireless signal being associated with the third temperature signal.
• Item 10 The circuit breaker of any of Items 8-9, further comprising: a second assembly for a second phase comprising a fifth interface terminal configured to interface with a sixth interface terminal of the switchgear to receive a fifth temperature signal from the sixth interface terminal, the fifth temperature signal indicating a fifth temperature sensed by a fifth temperature sensor in the switchgear; and a seventh interface terminal configured to interface with an eighth interface terminal of the switchgear to receive a seventh temperature signal form the eighth interface terminal, the seventh temperature signal indicating a seventh temperature sensed by a seventh temperature sensor in the switchgear; 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 ninth temperature signal indicating a ninth temperature sensed by a ninth temperature sensor in the switchgear; and an eleventh interface terminal configured to interface with an twelfth interface terminal of the switchgear to receive an eleventh temperature signal from the twelfth interface terminal, the eleventh temperature signal indicating an eleventh temperature sensed by an eleventh temperature sensor in the switchgear.
• 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 lateral surface of the first arm, the second temperature sensor configured to generate a second temperature signal indicating a second temperature of a location near a movable contact of the circuit breaker.
• Item 12 The circuit breaker of any of Items 8-11, further comprising the first temperature sensor adapted to be provided at or near a bus bar in the switchgear and coupled to the second interface terminal through a connection wire in a tube of equal potential in the switchgear.
• 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 pogopin; and the first temperature sensor comprises one of a thermal resistor, a thermal integrated circuit chip, or a thermal coupler.
• Item 14 It is provided a switchgear comprising a circuit breaker of any of Items 8-13.
• the method comprises providing an energy harvester configured to harvest energy of a switchgear; providing a first interface terminal 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 indicating a first temperature sensed by a first temperature sensor in the switchgear; 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 supplied from the energy harvester, the first wireless signal being associated with the first temperature signal.

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• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Gas-Insulated Switchgears (AREA)
• Breakers (AREA)

Applications Claiming Priority (1)

Publications (1)

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• 2020
  • 2020-11-19 EP EP20961923.8A patent/EP4248228A1/de active Pending
  • 2020-11-19 WO PCT/CN2020/130034 patent/WO2022104632A1/en active Application Filing
  • 2020-11-19 CN CN202080106789.2A patent/CN116601507A/zh active Pending

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