Apparatus and method for protecting solid state circuit breaker

Abstract

In accordance with an embodiment of the present disclosure, an apparatus and method for protecting a solid state circuit breaker are provided. The device comprises a temperature detection unit which is configured to detect the shell temperature of each transient voltage suppressor tube in one or more transient voltage suppressor tubes; and a control unit configured to: receive the housing temperature of the one or more transient voltage suppressor tubes from the temperature detection unit; for each transient voltage suppressor tube of the one or more transient voltage suppressor tubes, the first switching device and the second switching device are switched from the on state to the off state based on the shell temperature before the first switching device and the second switching device are switched from the on state to the off state. Predicting the junction temperature of each transient voltage suppressor tube in the one or more transient voltage suppressor tubes after the first switching device and the second switching device are switched from the on state to the off state; and generating a first alarm signal in response to the fact that the junction temperature of at least one transient voltage suppressor tube in the one or more transient voltage suppressor tubes exceeds a preset temperature threshold value.

Description

Technical Field

[0001] The exemplary embodiments of the present disclosure generally relate to the field of electrical equipment, and particularly to devices and methods for protecting solid-state circuit breakers, solid-state circuit breakers, and computer-readable storage media. Background Art

[0002] A circuit breaker is a switching device responsible for opening and closing the current in a normal circuit state and capable of closing and carrying the current in an abnormal circuit state within a specified time. A solid-state circuit breaker is the future development trend of terminal power distribution equipment, which realizes the on-off control of the main circuit through contactless switching devices. In a solid-state circuit breaker, a transient voltage suppression diode (TVS) is the most direct and effective means to protect the solid-state switching device from being broken down by the voltage generated by the line inductance. With the continuous increase of the current rating of the solid-state circuit breaker and the line inductance in the actual application scenario, the induced voltage generated by the line inductance borne by the solid-state circuit breaker is getting larger and larger, which poses a great challenge to the lifespan of protection devices such as transient voltage suppression diodes. In addition, overcurrent phenomena such as lightning strikes also occur in the actual application scenario, which also pose challenges to the lifespan and stability of transient voltage suppression diodes. Summary of the Invention

[0003] The embodiments of the present disclosure provide devices and methods for protecting solid-state circuit breakers, solid-state circuit breakers, and computer-readable storage media to at least partially address the above and other potential problems existing in the prior art.

[0004] In a first aspect of the present disclosure, a device for protecting a solid-state circuit breaker is provided. The solid-state circuit breaker includes a first switching device, a second switching device, and a first transient voltage suppression unit. The first switching device and the second switching device are connected in series, and both the first switching device and the second switching device are connected in parallel with the first transient voltage suppression unit. The first transient voltage suppression unit includes one or more transient voltage suppression diodes. The device includes: a temperature detection unit configured to detect the housing temperature of each of the one or more transient voltage suppression diodes; and a control unit configured to: receive the housing temperature of the one or more transient voltage suppression diodes from the temperature detection unit; for each of the one or more transient voltage suppression diodes, predict the junction temperature of each of the one or more transient voltage suppression diodes after the first switching device and the second switching device switch from the conducting state to the off state based on the housing temperature before the first switching device and the second switching device switch from the conducting state to the off state; and generate a first alarm signal in response to the junction temperature of at least one of the one or more transient voltage suppression diodes exceeding a predetermined temperature threshold.

[0005] In a second aspect of the present disclosure, a method for protecting a solid-state circuit breaker is provided. The solid-state circuit breaker includes a first switching device, a second switching device, and a first transient voltage suppression unit. The first switching device and the second switching device are connected in series, and both the first switching device and the second switching device are connected in parallel with the first transient voltage suppression unit. The first transient voltage suppression unit includes one or more transient voltage suppression diodes. The method includes: receiving, from a temperature detection unit, the case temperature of the one or more transient voltage suppression diodes, the temperature detection unit being configured to detect the case temperature of each of the one or more transient voltage suppression diodes; for each of the one or more transient voltage suppression diodes, predicting, based on the case temperature before the first switching device and the second switching device switch from an on state to an off state, the junction temperature of each of the one or more transient voltage suppression diodes after the first switching device and the second switching device switch from the on state to the off state; and generating a first alarm signal in response to the junction temperature of at least one of the one or more transient voltage suppression diodes exceeding a predetermined temperature threshold.

[0006] In a third aspect of the present disclosure, a solid-state circuit breaker is provided, including the device according to the first aspect of the present disclosure.

[0007] In a fourth aspect of the present disclosure, a computer-readable storage medium is provided, having stored thereon a computer program that can be executed by a processor to implement the method according to the second aspect of the present disclosure.

[0008] According to an embodiment of the present disclosure, the operating state of the transient voltage suppression diode in the solid-state circuit breaker can be diagnosed. In the case where it is necessary to turn off the switching device, the junction temperature of the transient voltage suppression diode after the switching device is turned off can be predicted in advance based on the surface temperature of the transient voltage suppression diode, and an alarm is given when the junction temperature exceeds a predetermined temperature threshold. In this way, potential safety hazards of the transient voltage suppression diode can be detected in a timely manner, ensuring the safe and reliable operation of the solid-state circuit breaker.

[0009] It should be understood that the content described in this part is not intended to limit the key features or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] With reference to the accompanying drawings and the following detailed description, the above and other features, advantages, and aspects of the embodiments of the present disclosure will become more apparent. In the drawings, the same or similar reference numerals denote the same or similar elements, where:

[0011] Figure 1 The circuit schematic diagram of the solid-state circuit breaker according to some embodiments of the present disclosure is shown;

[0012] Figure 2 An example arrangement of the temperature sensor on the transient voltage suppression diode according to some embodiments of the present disclosure is shown;

[0013] Figures 3A to 3D The rated parameters of the transient voltage suppression diode according to some embodiments of the present disclosure are shown;

[0014] Figure 4 The flowchart of the process for protecting the solid-state circuit breaker according to some embodiments of the present disclosure is shown; and

[0015] Figure 5 The block diagram of the device capable of implementing multiple embodiments of the present disclosure is shown. Detailed Description of Specific Embodiments

[0016] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. On the contrary, these embodiments are provided to more thoroughly and completely understand the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not used to limit the protection scope of the present disclosure.

[0017] In the description of the embodiments of the present disclosure, the term "including" and its like should be understood as an open inclusion, that is, "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The term "some embodiments" should be understood as "at least some embodiments". There may also be other explicit and implicit definitions below. The terms "first", "second", etc. may refer to different or the same objects. There may also be other explicit and implicit definitions below.

[0018] As described above, with the continuous increase of the current rating of the solid-state circuit breaker and the line inductance in the actual application scenario, the induced voltage generated by the line inductance on the solid-state circuit breaker is getting larger and larger, which poses a great challenge to the life of protection devices such as transient voltage suppressors. In addition, overcurrent phenomena such as lightning strikes may also occur in the actual application scenario, which also poses challenges to the life and stability of the transient voltage suppressor. Embodiments of the present disclosure provide a solution for protecting a solid-state circuit breaker, which can diagnose the working state of the transient voltage suppressor in the solid-state circuit breaker; in the case where it is necessary to turn off the switching device, the junction temperature of the transient voltage suppressor after the switching device is turned off can be predicted in advance according to the surface temperature of the transient voltage suppressor, and an alarm is given when the junction temperature exceeds a predetermined temperature threshold. The principle of the present disclosure will be described below in conjunction with Figures 1 to 5 the principle of the present disclosure will be described.

[0019] Figure 1 The circuit schematic diagram of the solid-state circuit breaker of some embodiments of the present disclosure is shown. Figure 1 The principle of the present disclosure is described by taking the solid-state circuit breaker provided only in the single-phase circuit of the main circuit as an example. It should be understood that in the embodiments of the present disclosure, a solid-state circuit breaker may be provided for each phase circuit respectively, or a solid-state circuit breaker may be provided in a part of the multi-phase circuit, and these implementations all fall within the scope of the present disclosure.

[0020] Figure 1 An L-phase line and an N-phase line are shown. The L-phase line is connected to the positive pole of the power supply PW, and the N-phase line is connected to the negative pole of the power supply PW and connected to the ground GND. A disconnect switch CB1 is provided in the L-phase line, and a disconnect switch CB1 is provided in the N-phase line.

[0021] As Figure 1 shown, the solid-state circuit breaker described herein includes an input terminal IN and an output terminal OUT. The input terminal IN is connected to the disconnect switch CB1, and the output terminal OUT is used to provide an output voltage Vout to the subsequent circuit.

[0022] As Figure 1As shown, the solid-state circuit breaker further includes a first switching device Q1 and a second switching device Q2 connected in series between the input terminal IN and the output terminal OUT. The first switching device Q1 and the second switching device Q2 are respectively formed with freewheeling diodes. The first switching device Q1 and the second switching device Q2 are main circuit solid-state switches for controlling the on / off state of the main circuit. The first switching device Q1 and the second switching device Q2 can include various conventional or future-available types. In one embodiment, the first switching device Q1 and the second switching device Q2 can include metal-oxide-semiconductor field-effect transistors (MOSFETs), such as SiC MOSFETs. In another embodiment, the first switching device Q1 and the second switching device Q2 can include insulated-gate bipolar transistors (IGBTs).

[0023] As Figure 1 shown, the solid-state circuit breaker further includes a first transient voltage suppression unit 11, and the first transient voltage suppression unit 11 is connected in parallel with both the first switching device Q1 and the second switching device Q2. The first transient voltage suppression unit 11 can include one or more transient voltage suppression diodes 110. When the first switching device Q1 and the second switching device Q2 switch from the on state to the off state, the line inductance can generate an induced voltage. When the induced voltage reaches a certain voltage level, the transient voltage suppression diodes 110 in the first transient voltage suppression unit 11 can be broken down, so that the first transient voltage suppression unit 11 conducts, to prevent the first switching device Q1 and the second switching device Q2 from being broken down. When the transient voltage suppression diodes 110 in the first transient voltage suppression unit 11 conduct, a high current will be generated in the transient voltage suppression diodes 110. Under the action of the high voltage and the high current, the temperature of the transient voltage suppression diodes 110 in the first transient voltage suppression unit 11 will rise instantaneously.

[0024] In one embodiment, as Figure 1 shown, the first transient voltage suppression unit 11 includes two transient voltage suppression diodes 110, namely TVS1 and TVS2. It should be understood that depending on the voltage level of the induced voltage generated by the line inductance when the first switching device Q1 and the second switching device Q2 are disconnected, the first transient voltage suppression unit 11 can include more or fewer transient voltage suppression diodes 110. For example, when the voltage of the induced voltage generated by the line inductance when the first switching device Q1 and the second switching device Q2 are disconnected is low, the first transient voltage suppression unit 11 can include only a single transient voltage suppression diode 110. When the voltage of the induced voltage generated by the line inductance when the first switching device Q1 and the second switching device Q2 are disconnected is high, the first transient voltage suppression unit 11 can include three or more transient voltage suppression diodes 110.

[0025] As Figure 1As shown, the solid-state circuit breaker described in this document includes a device for protecting the solid-state circuit breaker. This device can diagnose the operating state of the transient voltage suppressor 110 in the solid-state circuit breaker, timely detect potential safety hazards that may exist in the transient voltage suppressor 110, and ensure the safe and reliable operation of the solid-state circuit breaker. For ease of description, the device for protecting the solid-state circuit breaker described in this document may also be referred to as a protection device.

[0026] In some embodiments, as Figure 1 shown, the protection device includes a temperature detection unit 12 and a control unit 10. The temperature detection unit 12 is used to detect the case temperature of each transient voltage suppressor 110 in the first transient voltage suppression unit 11. The control unit 10 is used to diagnose the operating state of each transient voltage suppressor 110 based on the case temperature detected by the temperature detection unit 12.

[0027] In some embodiments, as Figure 1 shown, the temperature detection unit 12 includes one or more temperature sensors 121, which are respectively used to detect the case temperature of the corresponding transient voltage suppressor 110. For example, when the first transient voltage suppression unit 11 includes two transient voltage suppressors 110, the temperature detection unit 12 may include two temperature sensors 121, each detecting the case temperature of the corresponding transient voltage suppressor 110. When the first transient voltage suppression unit 11 includes more or fewer transient voltage suppressors 110, the temperature detection unit 12 may include more or fewer temperature sensors 121, respectively used to detect the case temperature of the corresponding transient voltage suppressor 110.

[0028] Figure 2 shows an example arrangement of the temperature sensor 121 on the transient voltage suppressor 110 according to some embodiments of the present disclosure. As Figure 2 shown, the temperature sensor 121 is fixed on the surface of the case of the corresponding transient voltage suppressor 110 for detecting the case temperature of the corresponding transient voltage suppressor 110. In some embodiments, the temperature sensor 121 may be fixed on the surface of the case of the corresponding transient voltage suppressor 110 by means of plastic potting. In some embodiments, the temperature sensor 121 may be fastened to the surface of the case of the corresponding transient voltage suppressor 110 by a metal foil. In some embodiments, the temperature sensor 121 may be fixed on the surface of the case of the corresponding transient voltage suppressor 110 by a dot of heat-resistant glue. In some embodiments, the temperature sensor 121 may be fixed on the surface of the case of the corresponding transient voltage suppressor 110 by a combination of multiple of the above fixing methods. It should be understood that in other embodiments, the temperature sensor 121 may also be fixed on the surface of the case of the corresponding transient voltage suppressor 110 by any other suitable means, and these implementations all fall within the scope of the present disclosure.

[0029] As Figure 1 shown, the temperature detection unit 12 is electrically connected to the control unit 10. The temperature detection unit 12 can be connected to the control unit 10 by wired or wireless means, and the embodiments of the present disclosure do not limit this.

[0030] The control unit 10 can receive the case temperature of each transient voltage suppression diode 110 from the temperature detection unit 12. Subsequently, for each transient voltage suppression diode 110, the control unit 10 can predict the junction temperature of each transient voltage suppression diode 110 after the first switching device Q1 and the second switching device Q2 switch from the on state to the off state based on the case temperature before the first switching device Q1 and the second switching device Q2 switch from the on state to the off state. The control unit 10 can diagnose the operating state of each transient voltage suppression diode 110 according to the predicted junction temperature of each transient voltage suppression diode 110. The control unit 10 can generate a first alarm signal in response to the junction temperature of at least one transient voltage suppression diode 110 among one or more transient voltage suppression diodes 110 exceeding a predetermined temperature threshold. The first alarm signal can remind the operator in any suitable manner. For example, the first alarm signal can remind the operator through at least one of sound and flash. In the embodiments of the present disclosure, the predetermined temperature threshold can be preset and stored in the control unit 10 according to design requirements.

[0031] In some embodiments, the control unit 10 can record the case temperature rise of each transient voltage suppression diode 110 in the first transient voltage suppression unit 11 each time the first switching device Q1 and the second switching device Q2 are normally turned off according to the actual installation situation. For each transient voltage suppression diode 110, the control unit 10 can calculate the average value of multiple temperature rise records respectively as the reference case temperature rise of each transient voltage suppression diode 110 when the first switching device Q1 and the second switching device Q2 are turned off once. Based on the obtained reference case temperature rise, the control unit 10 can automatically determine the change in the junction temperature of each transient voltage suppression diode 110 caused by the turn-off process before the first switching device Q1 and the second switching device Q2 are turned off each time. In the case where the determined junction temperature exceeds the predetermined temperature threshold, an alarm can be automatically given before the first switching device Q1 and the second switching device Q2 are turned off to prompt the operator that there may be a safety hazard in the transient voltage suppression diode 110.

[0032] In some embodiments, the junction temperature of each transient voltage suppression diode 110 can be determined by the following formula:

[0033] Tj = Tcase + delta_Tcase * K + Terr,

[0034] Where Tj represents the junction temperature of each transient voltage suppressor 110 predicted before the first switching device Q1 and the second switching device Q2 switch from the on state to the off state, Tcase represents the case temperature of each transient voltage suppressor 110 before the first switching device Q1 and the second switching device Q2 switch from the on state to the off state, delta_Tcase represents the average value of the case temperature rise of each transient voltage suppressor 110 under the condition of multiple normal turn-offs of the first switching device Q1 and the second switching device Q2 (i.e., the reference case temperature rise described above), K represents the conversion coefficient, and Terr is the predetermined temperature conversion error. Terr can be set according to the design requirements, for example, it is 10 °C.

[0035] It should be noted that the numbers, numerical values, etc. mentioned above and elsewhere in the present disclosure are exemplary and are not intended to limit the scope of the present disclosure in any way. Any other appropriate numbers and numerical values are possible.

[0036] In some embodiments, the control unit 10 may also record the number of times of instantaneous case temperature rise, and in response to the number of times of instantaneous case temperature rise reaching a predetermined number, generate a second alarm signal. The number of times of instantaneous case temperature rise represents the number of times the transient voltage suppressor 110 in the first transient voltage suppression unit 11 withstands surges, that is, the number of times the first switching device Q1 and the second switching device Q2 are turned off. The thickness of the PN junction (semiconductor-metal sheet) inside the transient voltage suppressor 110 in the first transient voltage suppression unit 11 is inversely proportional to the number of avalanche breakdowns. The thickness of the PN junction inside the transient voltage suppressor 110 becomes thinner each time a breakdown occurs. Therefore, the predetermined number can be preset and stored in the control unit 10. When the number of times of instantaneous case temperature rise is lower than the predetermined number, it indicates that the transient voltage suppressor 110 in the first transient voltage suppression unit 11 can operate reliably. When the number of times of instantaneous case temperature rise reaches the predetermined number, it indicates that there may be a safety risk in the transient voltage suppressor 110 in the first transient voltage suppression unit 11, so the control unit 10 can generate a second alarm signal to prompt the operator. In this way, the control unit 10 can ensure that the number of life times of the transient voltage suppressor 110 in the first transient voltage suppression unit 11 is within the specification requirements by recording the number of times of instantaneous case temperature rise of the transient voltage suppressor 110 in the first transient voltage suppression unit 11. The second alarm signal can be used to remind the operator in any appropriate way. For example, the second alarm signal can remind the operator through at least one of sound and flash. In the embodiments of the present disclosure, the predetermined number can be set according to the product design requirements, for example, it is 10,000 times, 30,000 times, 100,000 times, or other values.

[0037] In some implementations, such as Figure 1As shown, the protection device further includes a current detection unit 15, an input voltage detection unit 13, and an output voltage detection unit 14 connected to the control unit 10. The current detection unit 15 is configured to detect the current of the first transient voltage suppression unit 11. The input voltage detection unit 13 is configured to detect the input voltage of the first transient voltage suppression unit 11. The output voltage detection unit 14 is configured to detect the output voltage of the first transient voltage suppression unit 11. The control unit 10 can determine the voltage across the first transient voltage suppression unit 11 based on the input voltage and the output voltage, and determine whether the first transient voltage suppression unit 11 is operating in a normal state based on the current of the first transient voltage suppression unit 11 and the voltage across it. In response to the first transient voltage suppression unit 11 not operating in a normal state, the control unit 10 can generate a third alarm signal. The third alarm signal can be used to alert the operator in any suitable manner. For example, the third alarm signal can alert the operator through at least one of sound and flashing.

[0038] In some embodiments, the safety operating area curve, temperature derating curve, maximum single-pulse power, maximum clamping voltage, etc. of each transient voltage suppression diode 110 in the first transient voltage suppression unit 11 can be stored in the control unit 10 in advance. Figures 3A to 3D Some rated parameters of the transient voltage suppression diode according to some embodiments of the present disclosure are shown. As Figure 3A shown, the rated voltage of the transient voltage suppression diode 110 changes with the junction temperature. When the junction temperature exceeds 50 °C, the rated voltage of the transient voltage suppression diode 110 will gradually decrease. As Figure 3B shown, curve 301 shows the voltage change of the transient voltage suppression diode 110 in the first transient voltage suppression unit 11 when experiencing a surge, and curve 302 shows the current change of the transient voltage suppression diode 110 when experiencing a surge. As Figure 3C shown, the maximum single-pulse power of the transient voltage suppression diode 110 changes with the pulse width. As Figure 3D shown, the breakdown voltage of the transient voltage suppression diode 110 changes with the junction temperature.

[0039] In some embodiments, the control unit 10 may determine whether the first transient voltage suppression unit 11 operates in a normal state in the following manner. The control unit 10 may determine whether each transient voltage suppression diode 110 in the first transient voltage suppression unit 11 touches at least one of the safe operating area curve, the temperature derating curve, the maximum single-pulse power, and the maximum clamping voltage. In response to the first transient voltage suppression unit 11 not touching at least one of the safe operating area curve, the temperature derating curve, the maximum single-pulse power, and the maximum clamping voltage, the control unit 10 may determine that the first transient voltage suppression unit 11 operates in a normal state. In response to the first transient voltage suppression unit 11 touching at least one of the safe operating area curve, the temperature derating curve, the maximum single-pulse power, and the maximum clamping voltage, the control unit 10 may determine that the first transient voltage suppression unit 11 has operated in an extreme state, that is, not in a normal state. In the case where the first transient voltage suppression unit 11 has operated in an extreme state, the control unit 10 may generate a third alarm signal to indicate a potential risk.

[0040] The transient voltage suppression diodes 110 in the first transient voltage suppression unit 11 cannot withstand overvoltage for a long time. For example, the longest time for the transient voltage suppression diodes 110 to withstand overvoltage may be 10 ms or shorter. Therefore, after an overvoltage appears in the solid-state circuit breaker, the mechanical switch must be tripped quickly within 10 ms to protect the subsequent transient voltage suppression diodes 110 and switching devices Q1 and Q2 from being damaged. For this purpose, in some embodiments, the protection device further includes a fuse 17 and a second transient voltage suppression unit 16, as Figure 1 shown.

[0041] As Figure 1 shown, the fuse 17 and the second transient voltage suppression unit 16 are connected in series with the electromagnetic coil L2 for tripping the mechanical switch. The fuse 17 is used to protect the second transient voltage suppression unit 16 from being blown by overcurrent for a long time. The second transient voltage suppression unit 16 may include one or more transient voltage suppression diodes 110. When the voltage across the second transient voltage suppression unit 16 exceeds a first predetermined voltage threshold, the transient voltage suppression diodes 110 in the second transient voltage suppression unit 16 may conduct. When the voltage across the second transient voltage suppression unit 16 exceeds a second predetermined voltage threshold (for example, an overvoltage occurs), the transient voltage suppression diodes 110 in the second transient voltage suppression unit 16 may conduct and cause the electromagnetic coil L2 to trip the mechanical switch. The second predetermined voltage threshold is higher than the first predetermined voltage threshold.

[0042] In the case where the system voltage exceeds the breakdown voltage of the second transient voltage suppression unit 16 (i.e., the first predetermined voltage threshold, such as 860V), the second transient voltage suppression unit 16 will be gradually turned on, causing the current flowing through the second transient voltage suppression unit 16 to continuously increase. The electromagnetic coil L2 has a fixed resistance value R (such as 8.6 ohm) and is used to limit the maximum current flowing through the second transient voltage suppression unit 16, such as 100A. In the event of an overvoltage (exceeding the second predetermined voltage threshold), the current flowing through the second transient voltage suppression unit 16 will flow through the electromagnetic coil L2. When the current is large enough to exceed the trip current threshold of the electromagnetic coil L2, the electromagnetic coil L2 will drive the mechanical switch to trip. The entire trip process of the mechanical switch is not affected by the control unit 110 and other circuits. Theoretically, the maximum trip time only depends on the size of the electromagnetic coil L2 and the mechanical delay. Therefore, the entire trip time can be significantly reduced, such as within 10 ms.

[0043] The following refers to Figure 4 to describe the flowchart of process 400 for protecting the solid-state circuit breaker. Process 400 can be executed by the protection device described above, such as being executed by the control unit 10 in the protection device.

[0044] In block 410, the control unit 10 receives the case temperature of one or more transient voltage suppression diodes 110 from the temperature detection unit 12. The temperature detection unit 12 can adopt the configuration described above for detecting the case temperature of each transient voltage suppression diode 110.

[0045] In block 420, for each transient voltage suppression diode 110, the control unit 10 predicts the junction temperature of each transient voltage suppression diode 110 after the first switching device Q1 and the second switching device Q2 switch from the on state to the off state, based on the case temperature before the first switching device Q1 and the second switching device Q2 switch from the on state to the off state. The control unit 10 can predict the junction temperature in the manner described above.

[0046] In block 430, in response to the junction temperature of at least one of the one or more transient voltage suppression diodes 110 exceeding a predetermined temperature threshold, the control unit 10 generates a first alarm signal.

[0047] In some embodiments, the junction temperature of one or more transient voltage suppression diodes 110 is determined by the following formula:

[0048] Tj = Tcase + delta_Tcase * K + Terr,

[0049] Where Tj represents the junction temperature of each transient voltage suppressor 110 predicted before the first switching device Q1 and the second switching device Q2 switch from the on state to the off state, Tcase represents the case temperature of each transient voltage suppressor 110 before the first switching device Q1 and the second switching device Q2 switch from the on state to the off state, delta_Tcase represents the average value of the temperature rise of the case temperature of each transient voltage suppressor 110 in the case of multiple normal turn-offs of the first switching device Q1 and the second switching device Q2, K represents the conversion coefficient, and Terr is the predetermined temperature conversion error.

[0050] In some embodiments, process 400 further includes: recording the number of times of instantaneous temperature rise of the case temperature; and generating a second alarm signal in response to the number of times of instantaneous temperature rise reaching a predetermined number.

[0051] In some embodiments, process 400 further includes: receiving the current of the first transient voltage suppression unit 11 from the current detection unit 15; receiving the input voltage of the first transient voltage suppression unit 11 from the input voltage detection unit 13; receiving the output voltage of the first transient voltage suppression unit 11 from the output voltage detection unit 14; determining the voltage across the first transient voltage suppression unit 11 based on the input voltage and the output voltage; determining whether the first transient voltage suppression unit 11 operates in a normal state based on the current of the first transient voltage suppression unit 11 and the voltage across it; and generating a third alarm signal in response to the first transient voltage suppression unit 11 not operating in a normal state.

[0052] In some embodiments, determining whether the first transient voltage suppression unit 11 operates in a normal state based on the current of the first transient voltage suppression unit 11 and the voltage across it includes: determining whether the first transient voltage suppression unit 11 touches at least one of the safe operating area curve, the temperature derating curve, the maximum single-pulse power, and the maximum clamping voltage; determining that the first transient voltage suppression unit 11 operates in a normal state in response to the first transient voltage suppression unit 11 not touching at least one of the safe operating area curve, the temperature derating curve, the maximum single-pulse power, and the maximum clamping voltage; and determining that the first transient voltage suppression unit 11 does not operate in a normal state in response to the first transient voltage suppression unit 11 touching at least one of the safe operating area curve, the temperature derating curve, the maximum single-pulse power, and the maximum clamping voltage.

[0053] Figure 5 A block diagram of an electronic device 500 is shown in which one or more embodiments of the present disclosure may be implemented. It should be understood that Figure 5 The illustrated electronic device 500 is merely exemplary and should not constitute any limitation to the functions and scopes of the embodiments described herein. Figure 5The illustrated electronic device 500 can be used to implement Figure 1 at least a portion of the protection device or control unit 10 of

[0054] As Figure 5 shown, the electronic device 500 is in the form of a general-purpose electronic device. The components of the electronic device 500 may include, but are not limited to, one or more processors or processing units 510, a memory 520, a storage device 530, one or more communication units 540, one or more input devices 550, and one or more output devices 560. The processing unit 510 may be an actual or virtual processor and is capable of performing various processes according to programs stored in the memory 520. In a multi-processor system, multiple processing units execute computer-executable instructions in parallel to improve the parallel processing ability of the electronic device 500.

[0055] The electronic device 500 generally includes multiple computer storage media. Such media can be any accessible media that can be obtained by the electronic device 500, including but not limited to volatile and non-volatile media, removable and non-removable media. The memory 520 may be a volatile memory (such as registers, caches, random access memory (RAM)), a non-volatile memory (such as read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory), or some combination thereof. The storage device 530 may be a removable or non-removable medium and may include a machine-readable medium, such as a flash drive, a magnetic disk, or any other medium that can be used to store information and / or data (such as training data for training) and can be accessed within the electronic device 500.

[0056] The electronic device 500 may further include additional removable / non-removable, volatile / non-volatile storage media. Although not shown in Figure 5 it, a disk drive for reading from or writing to a removable, non-volatile magnetic disk (such as a "floppy disk") and an optical disk drive for reading from or writing to a removable, non-volatile optical disk may be provided. In these cases, each drive may be connected to a bus (not shown) by one or more data media interfaces. The memory 520 may include a computer program product 525 having one or more program modules that are configured to perform the various methods or actions of the various embodiments of the present disclosure.

[0057] The communication unit 540 enables communication with other electronic devices via a communication medium. Additionally, the functions of the components of the electronic device 500 can be implemented by a single computing cluster or multiple computer machines that are capable of communicating via a communication connection. Thus, the electronic device 500 can operate in a networked environment using a logical connection to one or more other servers, network personal computers (PCs), or another network node.

[0058] The input device 550 can be one or more input devices such as a mouse, keyboard, trackball, etc. The output device 560 can be one or more output devices such as a display, speaker, printer, etc. The electronic device 500 can also communicate with one or more external devices (not shown) as needed via the communication unit 540, external devices such as storage devices, display devices, etc., communicate with one or more devices that enable a user to interact with the electronic device 500, or communicate with any device that enables the electronic device 500 to communicate with one or more other electronic devices (e.g., network card, modem, etc.). Such communication can be performed via an input / output (I / O) interface (not shown).

[0059] According to an exemplary implementation of the present disclosure, a device for protecting a solid-state circuit breaker is provided. The device includes at least one processing unit and at least one memory. The at least one memory is coupled to the at least one processing unit and stores instructions for execution by the at least one processing unit, and the instructions, when executed by the at least one processing unit, cause the device to perform the methods described above.

[0060] According to an exemplary implementation of the present disclosure, a computer-readable storage medium is provided, on which computer-executable instructions are stored, where the computer-executable instructions are executed by a processor to implement the methods described above. According to an exemplary implementation of the present disclosure, a computer program product is also provided, the computer program product being tangibly stored on a non-transitory computer-readable medium and including computer-executable instructions, and the computer-executable instructions being executed by a processor to implement the methods described above.

[0061] Aspects of the present disclosure are described herein with reference to the flowcharts and / or block diagrams of methods, apparatuses, devices, and computer program products according to the present disclosure. It should be understood that each block of the flowcharts and / or block diagrams, and combinations of blocks in the flowcharts and / or block diagrams, can be implemented by computer-readable program instructions.

[0062] These computer-readable program instructions can be provided to a processing unit of a general-purpose computer, special-purpose computer, or other programmable data processing apparatus to produce a machine such that, when the instructions are executed by the processing unit of the computer or other programmable data processing apparatus, an apparatus is created that implements the functions / acts specified in one or more boxes of the flowchart and / or block diagram. These computer-readable program instructions can also be stored in a computer-readable storage medium that causes a computer, programmable data processing apparatus, and / or other devices to function in a particular manner, such that the computer-readable medium storing the instructions comprises a manufacture including instructions that implement various aspects of the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0063] The computer-readable program instructions may be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable data processing apparatus, or other devices to produce a computer-implemented process such that the instructions executed on the computer, other programmable data processing apparatus, or other devices implement the functions / acts specified in one or more boxes of the flowchart and / or block diagram.

[0064] The flowcharts and block diagrams in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to various implementations of the present disclosure. In this regard, each box in the flowchart or block diagram may represent a module, segment, or portion of instructions, which comprises one or more executable instructions for implementing the specified logical function. In some alternative implementations, the functions noted in the boxes may occur out of the order noted in the figures. For example, two consecutive boxes may in fact be executed substantially in parallel, or they may sometimes be executed in the reverse order, depending on the functionality involved. It should also be noted that each box of the block diagrams and / or flowcharts, and combinations of boxes in the block diagrams and / or flowcharts, can be implemented by special-purpose hardware-based systems that perform the specified functions or acts, or combinations of special-purpose hardware and computer instructions.

[0065] The various implementations of the present disclosure have been described above. The foregoing description is exemplary, not exhaustive, and is not limited to the disclosed implementations. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described implementations. The choice of terms used herein is intended to best explain the principles of the implementations, the practical application, or improvements made to the technology in the marketplace, or to enable other ordinary skill in the art to understand the disclosed implementations.

Claims

1. A device for protecting a solid-state circuit breaker, the solid-state circuit breaker comprising a first switching device (Q1), a second switching device (Q2), and a first transient voltage suppression unit (11), the first switching device (Q1) being serially connected to the second switching device (Q2), both the first switching device (Q1) and the second switching device (Q2) being connected in parallel to the first transient voltage suppression unit (11), the first transient voltage suppression unit (11) comprising one or more transient voltage suppression diodes (110), the device comprising: a temperature detection unit (12) configured to detect the case temperature of each of the one or more transient voltage suppression diodes (110); and a control unit (10) configured to: receive the case temperature of the one or more transient voltage suppression diodes (110) from the temperature detection unit (12); for each of the one or more transient voltage suppression diodes (110), predict the junction temperature of each of the one or more transient voltage suppression diodes (110) after the first switching device (Q1) and the second switching device (Q2) switch from an on state to an off state, based on the case temperature before the first switching device (Q1) and the second switching device (Q2) switch from the on state to the off state; and generate a first alarm signal in response to the junction temperature of at least one of the one or more transient voltage suppression diodes (110) exceeding a predetermined temperature threshold.

2. The device according to claim 1, wherein the temperature detection unit (12) comprises one or more temperature sensors (121), the one or more temperature sensors (121) being fixed to the surface of the case of the corresponding one of the one or more transient voltage suppression diodes (110) by at least one of plastic potting, metal foil, and dot heat-resistant glue.

3. The device according to claim 1, wherein the junction temperature of the one or more transient voltage suppression diodes (110) is determined by the following formula: Tj = Tcase + delta_Tcase * K + Terr, Where Tj represents the junction temperature of each transient voltage suppressor (110) predicted before the first switching device (Q1) and the second switching device (Q2) switch from the on state to the off state, Tcase represents the case temperature of each transient voltage suppressor (110) among the one or more transient voltage suppressors (110) before the first switching device (Q1) and the second switching device (Q2) switch from the on state to the off state, delta_Tcase represents the average value of the temperature rise of the case temperature of each transient voltage suppressor (110) among the one or more transient voltage suppressors (110) in the case of multiple normal turn-offs of the first switching device (Q1) and the second switching device (Q2), K represents a conversion coefficient, and Terr is a predetermined temperature conversion error.

4. The apparatus according to claim 1, wherein the control unit (10) is further configured to: Record the number of times of instantaneous temperature rise of the case temperature; and Generate a second alarm signal in response to the number of times of instantaneous temperature rise reaching a predetermined number.

5. The apparatus according to claim 1, further comprising: A current detection unit (15), connected to the control unit (10) and configured to detect the current of the first transient voltage suppression unit (11); An input voltage detection unit (13), connected to the control unit (10) and configured to detect the input voltage of the first transient voltage suppression unit (11); and An output voltage detection unit (14), connected to the control unit (10) and configured to detect the output voltage of the first transient voltage suppression unit (11), and Wherein the control unit (10) is further configured to: Determine the voltage across the first transient voltage suppression unit (11) based on the input voltage and the output voltage; and Determine whether the first transient voltage suppression unit (11) operates in a normal state based on the current of the first transient voltage suppression unit (11) and the voltage across it; And Generate a third alarm signal in response to the first transient voltage suppression unit (11) not operating in a normal state.

6. The apparatus according to claim 5, wherein determining whether the first transient voltage suppression unit (11) operates in a normal state based on the current of the first transient voltage suppression unit (11) and the voltage across it includes: Determine whether the first transient voltage suppression unit (11) touches at least one of a safe operating area curve, a temperature derating curve, a maximum single-pulse power, and a maximum clamping voltage; Determine that the first transient voltage suppression unit (11) operates in a normal state in response to the first transient voltage suppression unit (11) not touching at least one of a safe operating area curve, a temperature derating curve, a maximum single-pulse power, and a maximum clamping voltage; And In response to the first transient voltage suppression unit (11) touching at least one of the safe operating area curve, temperature derating curve, maximum single-pulse power, and maximum clamping voltage, it is determined that the first transient voltage suppression unit (11) is not operating in a normal state.

7. The apparatus according to claim 1, further comprising: A fuse (17) and a second transient voltage suppression unit (16), serially connected to an electromagnetic coil (L2) for tripping a mechanical switch, the second transient voltage suppression unit (16) being configured to conduct when the voltage across its two ends exceeds a first predetermined voltage threshold, and to conduct and cause the electromagnetic coil (L2) to trip the mechanical switch when the voltage across its two ends exceeds a second predetermined voltage threshold.

8. A method for protecting a solid-state circuit breaker, the solid-state circuit breaker including a first switching device (Q1), a second switching device (Q2), and a first transient voltage suppression unit (11), the first switching device (Q1) being serially connected to the second switching device (Q2), both the first switching device (Q1) and the second switching device (Q2) being connected in parallel to the first transient voltage suppression unit (11), the first transient voltage suppression unit (11) including one or more transient voltage suppression tubes (110), the method comprising: Receiving, from a temperature detection unit (12), the case temperature of the one or more transient voltage suppression tubes (110), the temperature detection unit (12) being configured to detect the case temperature of each of the one or more transient voltage suppression tubes (110); For each of the one or more transient voltage suppression tubes (110), predicting the junction temperature of each of the one or more transient voltage suppression tubes (110) after the first switching device (Q1) and the second switching device (Q2) switch from an on state to an off state, based on the case temperature before the first switching device (Q1) and the second switching device (Q2) switch from the on state to the off state; And Generating a first alarm signal in response to the junction temperature of at least one of the one or more transient voltage suppression tubes (110) exceeding a predetermined temperature threshold.

9. The method according to claim 8, wherein the junction temperature of the one or more transient voltage suppression tubes (110) is determined by the following formula: Tj = Tcase + delta_Tcase * K + Terr, Where Tj represents the junction temperature of each transient voltage suppressor (110) predicted before the first switching device (Q1) and the second switching device (Q2) switch from the on state to the off state, Tcase represents the case temperature of each transient voltage suppressor (110) in the one or more transient voltage suppressors (110) before the first switching device (Q1) and the second switching device (Q2) switch from the on state to the off state, delta_Tcase represents the average value of the temperature rise of the case temperature of each transient voltage suppressor (110) in the one or more transient voltage suppressors (110) in the case of multiple normal turn-offs of the first switching device (Q1) and the second switching device (Q2), K represents a conversion coefficient, and Terr is a predetermined temperature conversion error.

10. The method according to claim 8, further comprising: recording the number of times of instantaneous temperature rise of the case temperature; and generating a second alarm signal in response to the number of times of the instantaneous temperature rise reaching a predetermined number of times.

11. The method according to claim 8, further comprising: receiving the current of the first transient voltage suppression unit (11) from the current detection unit (15); receiving the input voltage of the first transient voltage suppression unit (11) from the input voltage detection unit (13); receiving the output voltage of the first transient voltage suppression unit (11) from the output voltage detection unit (14); determining the voltage across the first transient voltage suppression unit (11) based on the input voltage and the output voltage; determining whether the first transient voltage suppression unit (11) operates in a normal state based on the current of the first transient voltage suppression unit (11) and the voltage across it; and generating a third alarm signal in response to the first transient voltage suppression unit (11) not operating in a normal state.

12. The method according to claim 11, wherein determining whether the first transient voltage suppression unit (11) operates in a normal state based on the current of the first transient voltage suppression unit (11) and the voltage across it includes: determining whether the first transient voltage suppression unit (11) touches at least one of a safe operating area curve, a temperature derating curve, a maximum single pulse power, and a maximum clamping voltage; determining that the first transient voltage suppression unit (11) operates in a normal state in response to the first transient voltage suppression unit (11) not touching at least one of a safe operating area curve, a temperature derating curve, a maximum single pulse power, and a maximum clamping voltage; and determining that the first transient voltage suppression unit (11) does not operate in a normal state in response to the first transient voltage suppression unit (11) touching at least one of a safe operating area curve, a temperature derating curve, a maximum single pulse power, and a maximum clamping voltage.

13. A solid-state circuit breaker, comprising the device according to any one of claims 1 to 7.

14. A computer-readable storage medium having stored thereon a computer program, which can be executed by a processor to implement the method according to any one of claims 8 to 12.

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