A protection circuit for a power device and a driving method thereof, and a power supply device

Abstract

The embodiment of the present disclosure discloses a protection circuit of a power device and a driving method thereof, and a power supply device. The protection circuit of the power device includes: an energy storage element, a first protection circuit, and a second protection circuit; the energy storage element is configured to absorb and store the instantaneous peak voltage generated when the power device changes from on to off to store energy, and release the stored instantaneous energy; the first protection circuit is configured to be turned on when the power device changes from on to off, and the peak voltage charges the energy storage element through the first protection circuit; the second protection circuit is configured to be turned on when the set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit. It can achieve good peak voltage absorption effect, low high-frequency loss and small impact current.

Description

Technical Field

[0001] The present disclosure relates to but is not limited to the field of power electronics technology, and in particular to a protection circuit of a power device and a driving method thereof, and a power supply device. Background Art

[0002] Among various power electronic devices, MOSFET and IGBT are two commonly used semiconductor power devices, which are used as high-speed switching switches in inverter, rectifier, chopper and other circuits. Due to their advantages of fast switching speed, small on-state voltage drop, large carrying current, high withstand voltage, and fast response speed, MOSFET and IGBT are widely used in modern industrial automation, automotive electronics, medical treatment, communications and other fields. At present, MOSFET and IGBT play an important role in automotive components such as motor controllers, on-board chargers, DCDC, and charging piles.

[0003] Due to the presence of stray inductance and load inductance in the power circuit loop, when the power device quickly switches from the on state to the off state, the current decreases from a large current to zero current in a very short time. A high spike voltage will be generated at both ends of the power device at the moment of shutdown. If the spike voltage exceeds the withstand voltage of the power device, the power device will be broken down and damaged. Summary of the invention

[0004] The embodiment of the present disclosure provides a protection circuit for a power device, comprising: an energy storage element, a first protection circuit and a second protection circuit;

[0005] The energy storage element is configured to absorb and store the instantaneous peak voltage generated when the power device changes from on to off to store energy, and release the stored instantaneous energy;

[0006] The first protection circuit is configured to be turned on when the power device changes from being on to being off, and the peak voltage charges the energy storage element through the first protection circuit;

[0007] The second protection circuit is configured to be turned on when a set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit.

[0008] An embodiment of the present disclosure further provides a power supply device, including a power device and a protection circuit of the power device described in any embodiment.

[0009] The embodiment of the present disclosure further provides a driving method of a protection circuit of a power device, which is configured to drive the protection circuit of the power device described in any embodiment, and the method includes:

[0010] The energy storage element absorbs and stores the instantaneous peak voltage generated when the power device changes from on to off to store energy; and releases the stored instantaneous energy;

[0011] The first protection circuit is turned on when the power device changes from on to off, and the peak voltage charges the energy storage element through the first protection circuit;

[0012] The second protection circuit is turned on when a set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit.

[0013] The protection circuit of a power device and its driving method and power supply device provided by at least one embodiment of the present disclosure have the following beneficial effects compared with the prior art:

[0014] When the power device is turned off, the energy storage element and the first protection circuit can be combined, and the peak voltage can charge the energy storage element through the first protection circuit to protect the power device from transient overvoltage. When the energy storage element is discharged, the energy storage element can be combined with the second protection circuit for discharge protection. The energy storage element can release the stored instantaneous energy through the second protection circuit, which can reduce the impact of the peak voltage released by the energy storage element on the power device.

[0015] Other features and advantages of the present disclosure will be described in the following description, and partly become apparent from the description, or be understood by implementing the present disclosure. Other advantages of the present disclosure can be realized and obtained by the schemes described in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation on the technical solution of the present disclosure.

[0017] Figure 1 A structural block diagram of a protection circuit for a power device provided in an embodiment of the present disclosure;

[0018] Figure 2 A circuit schematic diagram of a protection circuit for a power device provided in an exemplary embodiment of the present disclosure;

[0019] Figure 3 A schematic diagram of a charging circuit of a first capacitor C provided in an exemplary embodiment of the present disclosure;

[0020] Figure 4 A schematic diagram of a discharge circuit of a first capacitor C provided in an exemplary embodiment of the present disclosure;

[0021] Figure 5 A schematic diagram of a discharge circuit of a first capacitor C provided in another exemplary embodiment of the present disclosure;

[0022] Figure 6A circuit schematic diagram of a protection circuit for a power device provided in an exemplary embodiment of the present disclosure;

[0023] Figure 7 A timing diagram of a control circuit provided for an exemplary embodiment of the present disclosure;

[0024] Figure 8 A circuit schematic diagram of a protection circuit for a power device provided in accordance with another exemplary embodiment of the present disclosure;

[0025] Fig. 9 A timing diagram of a control circuit provided for an exemplary embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] The present disclosure describes multiple embodiments, but the description is exemplary rather than restrictive, and it is apparent to those skilled in the art that there may be more embodiments and implementations within the scope of the embodiments described in the present disclosure. Although many possible feature combinations are shown in the drawings and discussed in the specific embodiments, many other combinations of the disclosed features are possible. Unless specifically limited, any feature or element of any embodiment may be used in combination with any other feature or element in any other embodiment, or may replace any other feature or element in any other embodiment.

[0027] The present disclosure includes and contemplates combinations of features and elements known to those of ordinary skill in the art. The embodiments, features, and elements disclosed in the present disclosure may also be combined with any conventional features or elements to form a unique invention scheme defined by the claims. Any features or elements of any embodiment may also be combined with features or elements from other invention schemes to form another unique invention scheme defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present disclosure may be implemented individually or in any appropriate combination. Therefore, except for the limitations made according to the attached claims and their equivalents, the embodiments are not subject to other limitations. In addition, various modifications and changes may be made within the scope of protection of the attached claims.

[0028] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not rely on the specific order of the steps described herein, the method or process should not be limited to the steps in the specific order described. As will be appreciated by those of ordinary skill in the art, other orders of steps are also possible. Therefore, the specific order of the steps set forth in the specification should not be interpreted as a limitation to the claims. In addition, the claims for the method and / or process should not be limited to the steps performed in the order written, and those skilled in the art can easily understand that these orders can be changed and still remain within the spirit and scope of the disclosed embodiments.

[0029] Figure 1 A structural block diagram of a protection circuit for a power device provided in an embodiment of the present disclosure, such as Figure 1 As shown, the protection circuit of the power device may include: an energy storage element 11, a first protection circuit 12 and a second protection circuit 13. The protection circuit of the power device may be called a buffer circuit, the first protection circuit is a charging protection circuit of the energy storage element, and the second protection circuit is a discharging protection circuit of the energy storage element.

[0030] The energy storage element is configured to absorb and store the instantaneous peak voltage generated when the power device 14 changes from on to off to store energy, and release the stored instantaneous energy;

[0031] A first protection circuit is configured to be turned on when the power device changes from being on to being off, and the peak voltage charges the energy storage element through the first protection circuit;

[0032] The second protection circuit is configured to be turned on when a set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit.

[0033] When a power device is disconnected from a large current, a transient spike voltage will be generated at both ends of the power device due to the effect of stray inductance and load inductance in the loop. The embodiment of the present disclosure can absorb the transient spike voltage generated at the moment of power device shutdown and release the transient energy stored thereby by providing an energy storage element, a first protection circuit and a second protection circuit at both ends of the power device.

[0034] When the power device is turned off, the energy storage element and the first protection circuit can be combined, and the peak voltage charges the energy storage element through the first protection circuit, which plays a role in transient overvoltage protection for the power device. The first protection circuit can be a unidirectional conductive circuit with a voltage drop less than a set voltage drop value. When the power device is turned off, the first protection circuit is turned on, and the peak voltage generated at both ends of the power device charges the energy storage element through the first protection circuit. Since the voltage drop of the first protection circuit is small, the energy storage element can quickly absorb the peak voltage, and the effect of absorbing the peak voltage is better.

[0035] When the energy storage element is discharging, the energy storage element can be combined with the second protection circuit for discharge protection. The energy storage element releases the instantaneous energy stored last time through the second protection circuit. Due to the protection of the second protection circuit, the impact of the instantaneous energy released by the energy storage element on the power device can be mitigated, avoiding the problem of power device being broken down and damaged when the instantaneous energy released by the energy storage element exceeds the withstand voltage of the power device.

[0036] Figure 2 A circuit schematic diagram of a protection circuit for a power device provided in an exemplary embodiment of the present disclosure is shown in FIG. Figure 2 As shown, the energy storage element may include a first capacitor C, which may be referred to as an absorption capacitor, wherein a first end of the first capacitor is electrically connected to a first pole of the power device, a second end of the first capacitor is electrically connected to a first protection circuit and a second protection circuit, and the first protection circuit and the second protection circuit are electrically connected to a second pole of the power device. The first capacitor may absorb and store an instantaneous spike voltage generated when the power device changes from on to off, and the stored spike voltage may be released by the first capacitor.

[0037] In an exemplary embodiment of the present disclosure, Figure 2 As shown, the first protection circuit may include a first diode D1, an anode of the first diode is electrically connected to the second end of the first capacitor, and a cathode of the first diode is electrically connected to the second electrode of the power device.

[0038] When the power device Q is turned off, an instantaneous peak voltage will be generated at both ends of D and S of the power device Q. A circuit structure of a first capacitor combined with a unidirectional diode can be used, and the peak voltage charges the first capacitor C through the first diode D1, and the surge current absorption effect is good.

[0039] Figure 3 A schematic diagram of a charging circuit of a first capacitor C provided in an exemplary embodiment of the present disclosure is shown in FIG. Figure 3 As shown, at the moment of large current disconnection of the power device Q, due to the effect of stray inductance and load inductance in the loop, an instantaneous spike voltage will be generated at both ends of D and S of the power device Q, and the spike voltage will charge the first capacitor C through the first diode D1. Since the forward voltage drop of the first diode D1 is very small, the first capacitor C quickly absorbs the instantaneous surge current generated by the spike voltage. Based on the principle that the voltage of the first capacitor C cannot suddenly change, the voltage at both ends of the power device Q connected in parallel with the first capacitor C will not suddenly change, which can provide transient overvoltage protection for the power device Q. Among them, Figure 3 The arrow in the middle points to the charging circuit of the first capacitor C.

[0040] In an exemplary embodiment of the present disclosure, Figure 2As shown, the second protection circuit may include a current limiting resistor R and a switch Q1, the first end of the current limiting resistor is electrically connected to the second end of the first capacitor, the second end of the current limiting resistor is electrically connected to the first end of the switch, the second end of the switch is electrically connected to the second pole of the power device, and the control end of the switch serves as the control end of the second protection circuit.

[0041] When the first capacitor is discharged, an RC circuit combined with an electronic switch circuit structure can be used. Under the premise of fully absorbing the peak surge current, the loss generated when the first capacitor is discharged can be reduced to a minimum, and lower losses and higher efficiency can be achieved in high-frequency switching circuits.

[0042] Figure 4 A schematic diagram of a discharge circuit of a first capacitor C provided in an exemplary embodiment of the present disclosure is shown in FIG. Figure 4 As shown, the first capacitor C can be discharged through the power device Q, and the working process can be: in the next conduction cycle of the power device Q, the switch Q1 and the power device Q are turned on at the same time, and the first capacitor C forms a discharge loop through the power device Q, the switch Q1 and the current limiting resistor R. Due to the existence of the current limiting resistor R, the impact of the discharge current on the power device Q is relatively small. Among them, Figure 4 The arrow in the middle points to the discharge loop of the first capacitor C.

[0043] Figure 5 A schematic diagram of a discharge circuit of a first capacitor C provided in another exemplary embodiment of the present disclosure is shown in FIG. Figure 5 As shown, in some scenarios (such as a synchronous rectification circuit of an on-board DCDC), the external connection circuit of the power device Q has a discharge loop of the first capacitor C. Figure 6 As shown, in addition to discharging through the power device Q, the first capacitor C can also be discharged through other external circuits. Figure 5 The arrow in the middle points to the discharge loop of the first capacitor C.

[0044] In an exemplary embodiment of the present disclosure, the switch Q1 may include: a metal oxide semiconductor field effect transistor (Metal Oxide Semiconductor, referred to as MOS tube) or an insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, referred to as IGBT tube).

[0045] The control electrode of the MOS tube or the IGBT tube serves as the control end of the switch, the first electrode of the MOS tube or the IGBT tube serves as the first end of the switch, and the second electrode of the MOS tube or the IGBT tube serves as the second end of the switch.

[0046] The switch can adopt P-MOS tube, N-MOS tube or IGBT tube, which makes the circuit simple and the structure reliable.

[0047] In an exemplary embodiment of the present disclosure, Figure 2 As shown, the protection circuit of the power device also includes a control circuit, and the control circuit is electrically connected to the first power supply terminal, the second power supply terminal, the second protection circuit and the power device;

[0048] The control circuit is configured to output a first setting level signal or an inverted level signal of the first setting level to the power device under the control of the first power supply terminal, and to output a second setting level signal or an inverted level signal of the second setting level to the second protection circuit under the control of the second power supply terminal;

[0049] The second protection circuit being turned on when a set condition is met may include: the second protection circuit being turned on when a control terminal receives a second set level signal.

[0050] The control circuit can be connected to the power device Q to control the on or off of the power device Q. The control circuit can be connected to the control terminal of the second protection circuit to control the on or off of the switch Q1 in the second protection circuit and the on time of the switch Q1.

[0051] Through calibration, the turn-on time point and turn-on duration of the switch Q1 can be controlled by software in the optimal state, and the discharge depth of the first capacitor C can be controlled. Under the premise of fully absorbing the peak voltage surge current, the loss generated on the current limiting resistor when the first capacitor is discharged can be reduced to a minimum, especially in high-frequency switching circuits, with lower losses and higher efficiency.

[0052] In an exemplary embodiment of the present disclosure, the control circuit may include: a control chip, a first driving circuit and a second driving circuit;

[0053] A control chip configured to output a first control signal to the first driving circuit and output a second control signal to the second driving circuit;

[0054] The first driving circuit is configured to be connected to the first power supply terminal when the first control signal is valid and output a first set level signal to the power device; when the first control signal is invalid, output an inverted level signal of the first set level to the power device;

[0055] The second driving circuit is configured to be connected to the second power supply terminal when the second control signal is valid, and output a second set level signal to the control terminal of the second protection circuit; when the second control signal is invalid, output an inverted level signal of the second set level signal to the control terminal of the second protection circuit.

[0056] The power device Q can be controlled by the control chip and the first drive circuit, and the switch Q1 in the second protection circuit can be controlled by the control chip and the second drive circuit.

[0057] Figure 6 A circuit schematic diagram of a protection circuit for a power device provided in an exemplary embodiment of the present disclosure is shown in FIG. Figure 6 As shown, the second power supply terminal can be a second set level signal, and the second driving circuit can include: a second driving chip (such as Figure 6 The driver chip in 2).

[0058] The power supply terminal of the second driving chip is electrically connected to the second power supply terminal, the input terminal of the second driving chip is electrically connected to the control chip, and the output terminal of the second driving chip is electrically connected to the control terminal of the second protection circuit.

[0059] In an exemplary embodiment of the present disclosure, the first power supply terminal may be a first set level signal, and the first driving circuit may include: a first driving chip (such as Figure 6 The power supply terminal of the first driver chip is electrically connected to the first power supply terminal, the input terminal of the first driver chip is electrically connected to the control circuit, and the output terminal of the first driver chip is electrically connected to the power device.

[0060] In an exemplary embodiment of the present disclosure, the first power terminal VCC1 continuously provides a high level signal, and the second power terminal VCC2 continuously provides a low level signal.

[0061] In the disclosed embodiment, the control circuit may include a control chip (such as a microprocessor chip), a driver chip 1 and a driver chip 2, the driver chip 1 is connected to an external positive power supply +VCC, the driver chip 2 is connected to an external negative power supply -VCC, and the switch Q1 uses a P-MOS tube.

[0062] In an exemplary embodiment of the present disclosure, Figure 6 As shown, the control circuit may further include a first resistor R1 and a second resistor R2. One end of the first resistor R1 is electrically connected to the output end of the driver chip 2, the other end of the first resistor R1 is electrically connected to one end of the second resistor R2, and the other end of the second resistor R2 is electrically connected to the control electrode of the switch Q1. Figure 7 A timing diagram of a control circuit provided for an exemplary embodiment of the present disclosure is shown in FIG. Figure 7 As shown in the figure, when the power device Q is disconnected, the surge current generated by the peak voltage is discharged through the first capacitor C and the first diode D1. At this time, the first capacitor C is in a charged state. When the first control signal CS1 is a high-level signal and the second control signal CS2 is a low-level signal, the driver chip 1 is connected to an external positive power supply, and the power device Q is turned on. The driver chip 2 is connected to an external negative power supply, and the voltage output to point A by the driver chip 2 is a negative voltage. The switch Q1 is turned on, and the first capacitor C is turned on. Figure 4 The discharge is carried out along the arrow path shown. Figure 7 The horizontal axis t represents time, and the unit can be microseconds (us) or milliseconds (ms).

[0063] Figure 8 A circuit schematic diagram of a protection circuit for a power device provided by another exemplary embodiment of the present disclosure is shown in FIG. Figure 8 As shown, the second power supply terminal can be an inverted level signal of the second set level signal, and the second driving circuit can include: a second driving chip (such as Figure 8 The power supply terminal of the second driver chip is electrically connected to the second power supply terminal, the input terminal of the second driver chip is electrically connected to the control chip, the output terminal of the second driver chip is electrically connected to the input terminal of the level inversion circuit, and the output terminal of the level inversion circuit is electrically connected to the control terminal of the second protection circuit.

[0064] In an exemplary embodiment of the present disclosure, the first power supply terminal may be a first set level signal, and the first driving circuit may include: a first driving chip (such as Figure 8 The power supply terminal of the first driver chip is electrically connected to the first power supply terminal, the input terminal of the first driver chip is electrically connected to the control circuit, and the output terminal of the first driver chip is electrically connected to the power device.

[0065] In an exemplary embodiment of the present disclosure, the first power supply terminal VCC1 continuously provides a high level signal, and the second power supply terminal VCC2 continuously provides a high level signal.

[0066] In the embodiment of the present disclosure, the inverted level signal of the second setting level signal output by the second driving chip may be inverted by the level inversion circuit to output the second setting level signal.

[0067] In an exemplary embodiment of the present disclosure, Figure 8 As shown, the level inversion circuit may include: a second capacitor C1 and a second diode D2.

[0068] The first end of the second capacitor serves as the input end of the level inverting circuit, the second end of the second capacitor is electrically connected to the anode of the second diode, and the connection end of the two serves as the output end of the level inverting circuit.

[0069] In the disclosed embodiment, the control circuit may include a control chip (such as a microprocessor chip), a driver chip 1, a driver chip 2 and a level inversion circuit, the driver chip 1 is connected to an external positive power supply +VCC, the driver chip 2 is connected to an external positive power supply +VCC, and the switch Q1 uses a P-MOS tube.

[0070] In an exemplary embodiment of the present disclosure, Figure 8As shown, the control circuit may further include a first resistor R1, a second resistor R2 and a third resistor R3, and the second capacitor C1 and the third resistor R3 are connected in parallel. One end of the first resistor R1 is electrically connected to the common end of the second capacitor C and the second diode D2, the other end of the first resistor R1 is electrically connected to one end of the second resistor R2, the other end of the second resistor R2 is electrically connected to the cathode of the second diode D2 and to the ground SGND, and the common end of the first resistor R1 and the second resistor R2 is electrically connected to the control electrode of the switch Q1.

[0071] Fig. 9 A timing diagram of a control circuit provided for an exemplary embodiment of the present disclosure is shown in FIG. Fig. 9 As shown in the figure, when the power device Q is disconnected, the surge current generated by the peak voltage is discharged through the first capacitor C and the first diode D1. At this time, the first capacitor C is in a charging state. When the first control signal CS1 is a high-level signal and the second control signal CS2 is a low-level signal, the driver chip 1 is connected to the external positive power supply, and the power device Q is turned on. The driver chip 2 is connected to the external positive power supply. Due to the existence of the first capacitor C1 and the first diode D2, the voltage output to point A is clamped to a negative voltage. The switch Q1 is turned on, and the first capacitor C is turned on. Figure 4 The discharge is carried out along the arrow path shown. Fig. 9 The horizontal axis t represents time, and the unit can be microseconds (us) or milliseconds (ms).

[0072] The protection circuit of the power device provided in the embodiment of the present disclosure includes a first capacitor C, a current limiting resistor R, a first diode D1, an electronic switch Q1, a protected power device Q and a control circuit, etc., and has the advantages of good peak voltage absorption effect, low high-frequency loss and small impact current. It can solve the problems of large impact current, poor peak voltage absorption effect, large high-frequency loss or the inability to take all three into account in the energy storage element.

[0073] In an exemplary embodiment of the present disclosure, the first driving circuit may be a positive power supply, and the second driving circuit may be a positive power supply or a negative power supply. The circuit is simple and the structure is reliable.

[0074] The embodiment of the present disclosure also provides a power supply device, including a power device and a protection circuit of the power device. The protection circuit of the power device is the protection circuit of the power device provided by any of the above embodiments, and the implementation principle and implementation effect are similar, which will not be repeated here.

[0075] In an exemplary embodiment of the present disclosure, the power supply device may include at least one of the following: an on-board power supply, an on-board charger, a motor controller, a direct current converter (DCDC), and a charging pile.

[0076] The embodiment of the present disclosure further provides a driving method of a protection circuit of a power device, which is configured to drive the protection circuit of the power device, and the method includes:

[0077] The energy storage element absorbs and stores the instantaneous peak voltage generated when the power device changes from on to off to store energy; and releases the stored instantaneous energy;

[0078] The first protection circuit is turned on when the power device changes from on to off, and the peak voltage charges the energy storage element through the first protection circuit;

[0079] The second protection circuit is turned on when the set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit.

[0080] The protection circuit of the power device is the protection circuit of the power device provided by any of the aforementioned embodiments, and the implementation principle and implementation effect are similar, which will not be repeated here.

[0081] It will be appreciated by those skilled in the art that all or some of the steps, systems, and functional modules / units in the methods disclosed above may be implemented as software, firmware, hardware, and appropriate combinations thereof. In hardware implementations, the division between the functional modules / units mentioned in the above description does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed by several physical components in cooperation. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or implemented as hardware, or implemented as an integrated circuit, such as an application-specific integrated circuit. Such software may be distributed on a computer-readable medium, which may include a computer storage medium (or non-transitory medium) and a communication medium (or temporary medium). As known to those skilled in the art, the term computer storage medium includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to store the desired information and can be accessed by a computer. In addition, it is well known to those of ordinary skill in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave or other transport mechanism, and may include any information delivery media.

Claims

1. A protection circuit for a power device, characterized in that: include: An energy storage element, a first protection circuit and a second protection circuit; The energy storage element is configured to absorb and store the instantaneous peak voltage generated when the power device changes from on to off to store energy, and release the stored instantaneous energy; The first protection circuit is configured to be turned on when the power device changes from being on to being off, and the peak voltage charges the energy storage element through the first protection circuit; The second protection circuit is configured to be turned on when a set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit; The energy storage element comprises a first capacitor, a first end of the first capacitor is electrically connected to a first pole of the power device, a second end of the first capacitor is electrically connected to the first protection circuit and the second protection circuit, and the first protection circuit and the second protection circuit are electrically connected to a second pole of the power device; The protection circuit of the power device further comprises a control circuit, wherein the control circuit is electrically connected to the first power supply terminal, the second power supply terminal, the second protection circuit and the power device; The control circuit is configured to output a first setting level signal or an inverted level signal of the first setting level to the power device under the control of the first power supply terminal, and to output a second setting level signal or an inverted level signal of the second setting level to the second protection circuit under the control of the second power supply terminal; The second protection circuit being turned on when a set condition is met includes: the second protection circuit being turned on when a control end receives the second set level signal.

2. The protection circuit according to claim 1, characterized in that: The first protection circuit includes a first diode, an anode of the first diode is electrically connected to the second end of the first capacitor, and a cathode of the first diode is electrically connected to the second electrode of the power device.

3. The protection circuit according to claim 1, characterized in that: The second protection circuit includes a current limiting resistor and a switch, the first end of the current limiting resistor is electrically connected to the second end of the first capacitor, the second end of the current limiting resistor is electrically connected to the first end of the switch, the second end of the switch is electrically connected to the second pole of the power device, and the control end of the switch serves as the control end of the second protection circuit.

4. The protection circuit according to claim 3, characterized in that: The switch comprises: a metal oxide semiconductor field effect transistor MOS tube, or an insulated gate bipolar transistor IGBT tube; The control electrode of the MOS tube or the IGBT tube serves as the control end of the switch, the first electrode of the MOS tube or the IGBT tube serves as the first end of the switch, and the second electrode of the MOS tube or the IGBT tube serves as the second end of the switch.

5. The protection circuit according to claim 1, characterized in that: The control circuit comprises: a control chip, a first drive circuit and a second drive circuit; The control chip is configured to output a first control signal to the first driving circuit and output a second control signal to the second driving circuit; The first driving circuit is configured to connect to the first power supply terminal when the first control signal is valid and output a first set level signal to the power device; when the first control signal is invalid, output an inverted level signal of the first set level to the power device; The second driving circuit is configured to be connected to the second power supply terminal when the second control signal is valid, and output a second set level signal to the control terminal of the second protection circuit; when the second control signal is invalid, output an inverted level signal of the second set level signal to the control terminal of the second protection circuit.

6. The protection circuit according to claim 5, characterized in that: The second power supply terminal is a second set level signal, and the second driving circuit includes: a second driving chip; The power supply terminal of the second driving chip is electrically connected to the second power supply terminal, the input terminal of the second driving chip is electrically connected to the control chip, and the output terminal of the second driving chip is electrically connected to the control terminal of the second protection circuit.

7. The protection circuit according to claim 5, characterized in that: The second power supply terminal is an inverted level signal of a second set level signal, and the second driving circuit includes: a second driving chip and a level inverting circuit; The power supply terminal of the second driving chip is electrically connected to the second power supply terminal, the input terminal of the second driving chip is electrically connected to the control chip, the output terminal of the second driving chip is electrically connected to the input terminal of the level inversion circuit, and the output terminal of the level inversion circuit is electrically connected to the control terminal of the second protection circuit.

8. The protection circuit according to claim 7, characterized in that: The level inversion circuit comprises: a second capacitor and a second diode; The first end of the second capacitor serves as the input end of the level inverting circuit, the second end of the second capacitor is electrically connected to the anode of the second diode, and the connection end of the two serves as the output end of the level inverting circuit.

9. The protection circuit according to claim 5, characterized in that: The first power supply terminal is a first set level signal, and the first driving circuit includes: a first driving chip; The power supply terminal of the first driving chip is electrically connected to the first power supply terminal, the input terminal of the first driving chip is electrically connected to the control circuit, and the output terminal of the first driving chip is electrically connected to the power device.

10. The protection circuit according to claim 5, characterized in that: The first driving circuit is a positive power supply, and the second driving circuit is a positive power supply or a negative power supply.

11. A power supply device, characterized in that: The invention comprises a power device and a protection circuit for the power device according to any one of claims 1 to 10.

12. The power supply device according to claim 11, characterized in that: The power supply device includes at least one of the following: an on-board power supply, an on-board charger, a motor controller, a direct current converter DCDC and a charging pile.

13. A method for driving a protection circuit of a power device, characterized in that: A protection circuit configured to drive a power device according to any one of claims 1 to 10, the method comprising: The energy storage element absorbs and stores the instantaneous peak voltage generated when the power device changes from on to off to store energy; and releases the stored instantaneous energy; The first protection circuit is turned on when the power device changes from on to off, and the peak voltage charges the energy storage element through the first protection circuit; The second protection circuit is turned on when a set condition is met, and the energy storage element releases the stored instantaneous energy through the second protection circuit.

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