A shutoff device and power conversion equipment

Abstract

The present invention discloses a shutdown device and power conversion equipment, which relate to the field of electronic device shutdown control. The shutdown device includes a soft shutdown module, a desaturation detection module and a delay module. When the target controllable switch is in the desaturation working state, the soft shutdown module is first turned on to use the on-voltage when it is turned on to make the target controllable switch perform a soft shutdown. The delay module sends a first prompt signal to the drive module after a first preset time delay to make the drive module output a negative pressure signal, thereby making the target controllable switch perform a negative pressure shutdown. After receiving the wave-sealing prompt signal, the control module controls the drive module to stop signal output after a second preset time delay to make the target controllable switch perform a wave-sealing shutdown. This solution reduces the voltage stress of the target controllable switch, realizes the reliable shutdown of the target controllable switch under high noise and high current conditions, and is conducive to replacing the busbar copper bar with other low-cost materials to reduce costs.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic device shutdown control, and in particular to a shutdown device and power conversion equipment. Background Art

[0002] IGBT (Insulated Gate Bipolar Transistor) is a power semiconductor switching device with advantages such as low driving power and low saturation voltage, and is widely used in various power conversion devices. Taking power converter as an example, please refer to Figure 1 , Figure 1 The figure is a schematic structural diagram of a power converter in the prior art. Figure 1 The motor is represented by the reference symbol M, and the six IGBTs used for power conversion are represented by the reference symbols TV1, TV2, TV3, TV4, TV5 and TV6 respectively. The positive and negative busbars include miscellaneous inductance. Figure 1 In this paper, the inductance is represented by inductance Lr1 and inductance Lr2. To reduce costs, some manufacturers replace the busbar copper busbar with other low-cost materials, resulting in a large amount of inductance in the busbar. The presence of inductance has a significant impact on the reliable shutdown of the IGBT. Specifically, the greater the inductance, the higher the voltage spike during IGBT shutdown, and the lower the IGBT's shutdown reliability. Similarly, excessive output current and overcurrent of the IGBT will also affect the IGBT's shutdown reliability. Therefore, it is necessary to design a solution that can achieve reliable IGBT shutdown under high inductance and high current conditions.

[0003] Currently, the industry mostly adopts a hard shutdown method for the above-mentioned working conditions, that is, directly using a hardware clamping method, which often leads to overvoltage damage to the IGBT. In a small number of cases, active clamping solutions are used for shutdown, that is, an active clamping circuit is designed to feed back the IGBT's Vce voltage (the voltage between the IGBT's collector and emitter) to the IGBT's gate, thereby reducing the voltage spike at the moment of high current shutdown. However, the TVS tube used in the active clamping circuit has a large discreteness, making it impossible to accurately control the clamping voltage point. In addition, the active clamping circuit will remain in an operating state near the clamping voltage point, resulting in large losses in the TVS tube, and in severe cases, even damage to the TVS tube. The overall reliability of the solution is not high.

[0004] Therefore, how to provide a solution for reliably shutting down the IGBT under high noise and high current conditions to solve the above technical problems is a problem that technicians in this field currently need to solve. Summary of the Invention

[0005] The purpose of the present invention is to provide a shutdown device and a power conversion device. By setting a three-step shutdown mode, the voltage stress of the target controllable switch is reduced, and the target controllable switch can be reliably shut down under high-noise and high-current working conditions. In addition, in practical applications, it is beneficial to replace the busbar copper bar with other low-cost materials, thereby reducing costs.

[0006] In order to solve the above technical problems, the present invention provides a shutdown device applied to a switch driving device, wherein the shutdown device includes a soft shutdown module, a desaturation detection module and a delay module;

[0007] The soft shutdown module is respectively connected to the first switch module in the switch driving device, the driving module in the switch driving device, the desaturation detection module and the ground terminal, and the first switch module is also connected to the target controllable switch; the driving module is also connected to the control module, the desaturation detection module and the delay module in the switch driving device, and the desaturation detection module is also connected to the first power supply, the delay module and the target controllable switch;

[0008] The desaturation detection module is configured to send a first conduction signal to the delay module when the target controllable switch is in a desaturation working state, and send a second conduction signal to the soft shutdown module to turn on the soft shutdown module, so that the target controllable switch is soft-shutdown based on the turn-on voltage of the soft shutdown module; and stop sending the second conduction signal and send a stop signal to the delay module when the target controllable switch is in a non-desaturation working state;

[0009] The delay module is configured to, upon receiving the first on-state signal, send a first prompt signal to the driving module after a delay of a first preset time, so that the driving module outputs a negative pressure signal after receiving the first prompt signal, so that the target controllable switch performs a negative pressure shutdown based on the negative pressure signal; and prohibit outputting the first prompt signal upon receiving the stop signal;

[0010] The control module is configured to, after receiving the wave encapsulation prompt signal sent by the driving module based on the first prompt signal, send a wave encapsulation signal to the driving module after a second preset time delay to cause the driving module to stop signal output and cause the target controllable switch to be turned off by wave encapsulation.

[0011] Preferably, the delay module includes a first controllable switch, a first resistor and a first capacitor;

[0012] One end of the first resistor is connected to the first power supply and the desaturation detection module, and the other end of the first resistor is connected to the first end of the first controllable switch and one end of the first capacitor respectively, and the common end of the connections is connected to the protection end of the driving module;

[0013] The second end of the first controllable switch is connected to the other end of the first capacitor, and the common end of the connections is grounded. The control end of the first controllable switch is connected to the desaturation detection module.

[0014] The first controllable switch is used to turn on when receiving the stop signal; and turn off when receiving the first turn-on signal, so that the first capacitor starts charging, and then feeds back a first prompt signal to the driving module when the terminal voltage of the first capacitor reaches a preset voltage threshold.

[0015] Preferably, the desaturation detection module includes a second switch module, a second resistor, a second capacitor, a first voltage stabilizing diode and a second controllable switch;

[0016] The control end of the second switch module is connected to the output end of the driving module, the first end of the second switch module is respectively connected to one end of the second capacitor and the first end of the second controllable switch, and the common end of the connections is grounded, the second end of the second switch module is respectively connected to one end of the second resistor, one end of the first resistor, the second end of the second controllable switch, the soft shutdown module, and the control end of the first controllable switch, the third end of the second switch module is respectively connected to the other end of the second resistor, the other end of the second capacitor, the cathode of the first Zener diode, and the target controllable switch; the anode of the first Zener diode is connected to the control end of the second controllable switch;

[0017] The second switch module is configured to be turned off when the driving module outputs a driving signal for controlling the target controllable switch to be turned on, and to be turned on when the driving module outputs the negative pressure signal;

[0018] The first voltage regulator diode is used to turn on the second controllable switch when the target controllable switch is in a desaturated working state, thereby sending a first turn-on signal to the delay module and a second turn-on signal to the soft shutdown module, and turn off the second controllable switch when the target controllable switch is in a non-desaturated working state.

[0019] Preferably, the second switch module includes a third controllable switch and a fourth controllable switch;

[0020] The control end of the third controllable switch serves as the control end of the second switch module, the first end of the third controllable switch is connected to the control end of the fourth controllable switch, and the common end of the connections serves as the second end of the second switch module, the second end of the third controllable switch is connected to the first end of the fourth controllable switch, and the common end of the connections serves as the first end of the second switch module, and the second end of the fourth controllable switch serves as the third end of the second switch module;

[0021] The third controllable switch is configured to be turned on when the driving module outputs the driving signal, and turned off when the driving module outputs the negative pressure signal;

[0022] The fourth controllable switch is configured to be turned off when the third controllable switch is turned on, and to be turned on when the third controllable switch is turned off.

[0023] Preferably, the desaturation detection module includes a third switch module, a third resistor, a fourth resistor, a third capacitor, a comparison module, a second voltage stabilizing diode and a fifth controllable switch;

[0024] The control end of the third switch module is connected to the output end of the driving module. The first end of the third switch module is respectively connected to one end of the third capacitor, the anode of the second voltage stabilizing diode, and the first end of the fifth controllable switch, and the common end of the connections is grounded. The second end of the third switch module is respectively connected to one end of the third resistor, one end of the fourth resistor, the output end of the comparison module, the control end of the first controllable switch, one end of the first resistor, and the control end of the fifth controllable switch. The third end of the third switch module is respectively connected to the other end of the third capacitor, the first input end of the comparison module, the other end of the third resistor, and the target controllable switch.

[0025] The other end of the fourth resistor is connected to the cathode of the second voltage stabilizing diode and the second input end of the comparison module respectively; the second end of the fifth controllable switch is connected to the soft shutdown module;

[0026] The third switch module is configured to be turned off when the driving module outputs a driving signal for controlling the target controllable switch to be turned on, and to be turned on when the driving module outputs the negative pressure signal; the comparison module is configured to send a first turn-on signal to the delay module when the target controllable switch is in a desaturation working state, and turn on the fifth controllable switch to send a second turn-on signal to the soft shutdown module; and send a stop signal to the delay module and turn off the fifth controllable switch when the target controllable switch is in a non-desaturation working state.

[0027] Preferably, the soft shut-off device is also connected to the control module;

[0028] The control module is further configured to, when determining that the output current of the target controllable switch does not overcurrent and is in a non-de-saturation working state, send a first shutdown signal to the soft shutdown module to shut down the soft shutdown module; when determining that the output current overcurrent occurs and is in a non-de-saturation working state, send a third turn-on signal to the soft shutdown module to turn on the soft shutdown module, and maintain outputting a drive signal for controlling the conduction of the target controllable switch within a third preset time length to turn on the first switch module, so that the target controllable switch is soft-shut down based on the turn-on voltage of the soft shutdown module; and, when the third preset time length is reached, send a wave-blocking signal to the drive module to stop the signal output and turn off the first switch module, so that the target controllable switch is wave-blocked and shut down.

[0029] Preferably, the soft shutdown module includes a controllable switch module, a sixth controllable switch and a third voltage stabilizing diode;

[0030] The control end of the controllable switch module is connected to the control module, the first end of the controllable switch module is connected to the control end of the sixth controllable switch and the desaturation detection module, the second end of the controllable switch module is connected to the first end of the sixth controllable switch, and the common end of the connections is connected to the ground end;

[0031] The second end of the sixth controllable switch is connected to the anode of the third voltage stabilizing diode, and the cathode of the third voltage stabilizing diode is connected to the first switch module and the driving module respectively;

[0032] The controllable switch module is configured to be turned off upon receiving the first turn-off signal and turned on upon receiving the third turn-on signal;

[0033] The sixth controllable switch is configured to be turned on when the controllable switch module is turned on and / or receives the second turn-on signal, so as to turn on the third voltage regulator diode; and to be turned off when the controllable switch module is turned off and does not receive the second turn-on signal, so as to turn off the third voltage regulator diode.

[0034] Preferably, the controllable switch module includes an optical coupler and a seventh controllable switch;

[0035] The anode of the light-emitting diode of the optocoupler serves as the control terminal of the controllable switch module, and the cathode of the light-emitting diode is grounded; the emitter of the phototransistor of the optocoupler is connected to the control terminal of the seventh controllable switch, and the collector of the phototransistor is connected to the second power supply;

[0036] The first end of the seventh controllable switch serves as the first end of the controllable switch module, and the second end of the seventh controllable switch serves as the second end of the first controllable switch module;

[0037] The light emitting diode is configured to be turned on upon receiving the third turn-on signal, so as to turn on the phototransistor and thereby turn on the seventh controllable switch; and to be turned off upon receiving the first turn-off signal, so as to turn off the phototransistor and thereby turn off the seventh controllable switch.

[0038] Preferably, the shutdown device further includes a hardware overcurrent detection module;

[0039] The hardware overcurrent detection module is connected to the current acquisition module, the soft shutdown module and the control module respectively, and is used to control the soft shutdown module to turn on when detecting that the output current of the target controllable switch acquired by the current acquisition module is overcurrent and is in a non-desaturation working state, and send a third prompt signal indicating an overcurrent fault to the control module, so that the control module sends the enclosing signal to the driving module after delaying the third preset time after receiving the third prompt signal.

[0040] In order to solve the above technical problems, the present invention further provides a power conversion device, comprising a power conversion circuit and a switch driving device, and also comprising the shutdown device as described above;

[0041] The power conversion circuit includes a plurality of target controllable switches, and each of the target controllable switches is connected to the switch driving device and the shutoff device.

[0042] The present application provides a shutdown device and a power conversion device, wherein the shutdown device includes a soft shutdown module, a desaturation detection module and a delay module. When a target controllable switch is in a desaturation working state, the soft shutdown module is first turned on to use the on-voltage when it is turned on to make the target controllable switch softly shut down. The delay module sends a first prompt signal to the drive module after a first preset time delay, so that the drive module outputs a negative pressure signal, thereby causing the target controllable switch to perform a negative pressure shutdown. After receiving the wave blocking prompt signal, the control module controls the drive module to stop signal output after a second preset time delay to cause the target controllable switch to perform a wave blocking shutdown. By setting the above-mentioned three-step shutdown mode, this scheme reduces the voltage stress of the target controllable switch and realizes reliable shutdown of the target controllable switch under large inductance and large current conditions. In practical applications, it is beneficial to replace the busbar copper bar with other low-cost materials, thereby reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the prior art and the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0044] Figure 1 It is a structural diagram of a power converter in the prior art;

[0045] Figure 2 A schematic structural diagram of a shut-off device provided by the present invention;

[0046] Figure 3 A schematic structural diagram of a power converter provided by the present invention;

[0047] Figure 4 This is a schematic structural diagram of another shut-off device provided by the present invention. DETAILED DESCRIPTION

[0048] The core of the present invention is to provide a shutdown device and a power conversion device. By setting a three-step shutdown mode, the voltage stress of the target controllable switch is reduced, and the target controllable switch can be reliably shut down under high-noise and high-current working conditions. In practical applications, it is beneficial to replace the busbar copper bar with other low-cost materials, thereby reducing costs.

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0050] Please refer to Figure 1 and Figure 2 , Figure 1 It is a structural diagram of a power converter in the prior art. Figure 2 A schematic structural diagram of a shut-off device provided by the present invention;

[0051] In this embodiment, considering that the power conversion device includes multiple controllable switches, such as IGBTs, in actual applications, the busbar's inductance and output current overcurrent will cause the IGBT to operate under high inductance and high current conditions, seriously affecting its shutdown reliability. In the prior art, IGBT shutdown is achieved by either using direct hardware blocking or methods such as active clamping. These solutions are not highly reliable and cannot reliably achieve IGBT shutdown under these conditions. In some cases, the use of a shutdown chip designed specifically for these conditions is costly. To address the above technical issues, the present application provides a shutdown device that helps reduce the voltage stress of the target controllable switch under these conditions, minimizes damage to the target controllable switch, and is more conducive to practical application.

[0052] The shutdown device is applied to a switch driving device, and comprises a soft shutdown module 1, a desaturation detection module 4 and a delay module 5;

[0053] The soft shutdown module 1 is respectively connected to the first switch module 3 in the switch drive device, the drive module 2 in the switch drive device, the desaturation detection module 4, and the ground terminal. The first switch module 3 is also connected to the target controllable switch. The drive module 2 is also connected to the control module, the desaturation detection module 4, and the delay module 5 in the switch drive device. The desaturation detection module 4 is also connected to the first power supply, the delay module 5, and the target controllable switch.

[0054] The desaturation detection module 4 is configured to send a first conduction signal to the delay module 5 when the target controllable switch is in the desaturation working state, and send a second conduction signal to the soft shutdown module 1 to turn on the soft shutdown module 1, so that the target controllable switch is soft-shutdown based on the turn-on voltage of the soft shutdown module 1; and stop sending the second conduction signal and send a stop signal to the delay module 5 when the target controllable switch is in the non-desaturation working state;

[0055] The delay module 5 is configured to, upon receiving the first on-signal, send a first prompt signal to the driving module 2 after a delay of a first preset time, so that the driving module 2 outputs a negative pressure signal after receiving the first prompt signal, so that the target controllable switch performs a negative pressure shut-off based on the negative pressure signal; and prohibit outputting the first prompt signal upon receiving the stop signal;

[0056] The control module is used to send a wave-enclosing signal to the driving module 2 after receiving the wave-enclosing prompt signal sent by the driving module 2 based on the first prompt signal, after a delay of a second preset time, so that the driving module 2 stops signal output and the target controllable switch is closed by wave-enclosing.

[0057] Specifically, the target controllable switch can be an IGBT or a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), which is not particularly limited here. The switch driving device is a device originally used to normally drive the target controllable switch to be turned on and off. It can be understood that the switch driving device includes a control module, a driving module 2 and a first switch module 3. The control module includes but is not limited to an MCU (Microcontroller Unit); when the driving module 2 receives a driving signal sent by the control module at its own driving input end, it outputs a control signal for turning on the target controllable switch through its own output end, and the first switch module 3 is controlled to turn on, and then the target controllable switch module 11 is turned on; when the driving module 2 receives a wave-sealing signal sent by the control module at its own driving input end, its own output end will stop outputting the signal, and the first switch module 3 will be turned off, so that the target controllable switch is turned off by wave-sealing.

[0058] It should be noted that, considering that the target controllable switch is a power electronic device with a certain pressure-bearing capacity, when it is not desaturated and not overcurrent, it only needs to follow the above-mentioned normal control on and off logic to achieve normal on and off control of the target controllable switch without damaging the target controllable switch. Therefore, when the control module determines that the output current of the target controllable switch is not overcurrent, it controls the soft shutdown module 1 to shut down, and then only relies on the above-mentioned normal on and off logic to achieve control of the target controllable switch, so as to reduce switching loss, simplify control logic, and ensure shutdown control efficiency.

[0059] For more details, please refer to Figure 2 , Figure 2 In the example, the target controllable switch is an IGBT and the reference numeral of the IGBT is TV7. The IGBT may include a body diode. In fact, the IGBT may be Figure 1 Any one of the IGBTs in the power converter (i.e. any one of the IGBTs marked as TV1 to TV6 in the figure). As for the connection method of each part mentioned in this application, see Figure 2 The above text shows that the first power supply can be a +15V DC power supply.

[0060] From the perspective of circuit principle, when the target controllable switch is in the desaturation working state, its output current reaches the desaturation working current. Taking the target controllable switch as IGBT as an example, its Vce voltage (i.e. the voltage between its collector and emitter) will increase. On the one hand, the desaturation detection module 4 controls the soft shutdown module 1 to turn on. At this time, the driving module 2 itself normally outputs the +15V driving control signal, but due to the conduction of the soft shutdown module 1, the target controllable switch will be soft-turned off based on the turn-on voltage of the soft shutdown module 1; on the other hand, the desaturation detection module 4 sends a first turn-on signal to the delay module 5, the delay module 5 starts working, and sends a first prompt signal to the driving module 2 after delaying the first preset time length; it can be understood that within the first preset time length, the target controllable switch is soft-turned off. Shutdown; after receiving the first prompt signal, the driving module 2 outputs a negative pressure signal to turn on the first switch module 3, and the negative pressure signal includes but is not limited to an electrical signal of -10V, then the target controllable switch will be shut down by a negative pressure of -10V electrical signal; on the other hand, the driving module 2 also feeds back a wave-sealing prompt signal to the control module, so that after receiving the wave-sealing prompt signal, the control module sends a wave-sealing signal to the driving module 2 after a delay of a second preset time length so that the driving module 2 stops the signal output and turns off the first switch module 3, so that the target controllable switch performs wave-sealing shutdown; the specific value of the second preset time length is not particularly limited here, and finally a reliable and safe execution scheme of soft shutdown-negative pressure shutdown-wave-sealing shutdown of the target controllable switch in the desaturated state is realized.

[0061] It should also be noted that when the target controllable switch is in a non-desaturation working state, the desaturation detection module 4 stops sending the second conduction signal, that is, at this time the desaturation detection module 4 does not participate in the control of the conduction and shutdown of the soft shutdown module 1, and the conduction and shutdown of the soft shutdown module 1 are completely controlled by the control action of the control module and the hardware overcurrent detection module 6 (see the details in the following embodiment, which will not be repeated here), and at this time the desaturation detection module 4 also sends a stop signal to the delay module 5 to prohibit the delay module 5 from outputting the first prompt signal to the protection end of the driving module 2, that is, it will not trigger the fault feedback end of the driving module 2 to output the wave sealing prompt signal.

[0062] For further explanation as a setting example, please refer to Figure 2Taking into account the requirements of device application safety and voltage clamping in actual applications, the gate of the IGBT can be connected to the cathode of the fourth voltage zener diode Z2, one end of the fourth capacitor C7, one end of the fifth resistor R8, and one end of the sixth resistor R7. The other end of the fifth resistor R8 is connected to the emitter of the IGBT, the anode of the fourth voltage zener diode Z2, and the other end of the fourth capacitor C7, and the common end of the connections is grounded. The other end of the sixth resistor R7 is connected to the second end of the first switch module 3. The first switch module 3 includes an NPN transistor Q4 and a PNP transistor Q3, the collector of the NPN transistor Q4 is connected to the output end of the +15V power supply, the base of the NPN transistor Q4 is connected to the base of the PNP transistor Q3, and the common end of the connections is connected to the soft shutdown module 1, the driving module 2 and the desaturation detection module 4, the emitter of the NPN transistor Q4 is connected to the emitter of the PNP transistor Q3, and the common end of the connections is connected to the target controllable switch, and the collector of the PNP transistor Q3 is connected to the -10V power supply. The driving module 2 may include the following: Figure 2 Regarding the driver chip PC2 and its peripheral circuits described in the specification, it should be noted that the ANODE end of the driver chip PC2 is connected to the control module as the driving input end of the driver module 2 to receive the wave blocking signal and the normal conduction and shutdown control signal, and the VOUT end of the driver chip PC2 is connected to the soft shutdown module 1, the desaturation detection module 4, the delay module 5 and the first switch module 3 as the output end of the driver module 2, and considering the safety requirements of device operation, a seventh resistor R2 can also be set between the VOUT end of the driver chip PC2 and the first end of the first switch module 3; the DESAT end of the driver chip PC2 is connected to the delay module 5 as the protection end of the driver module 2 to receive the first prompt signal; the FAULT end of the driver chip PC2 is connected to the control module as the fault feedback end of the driver module 2 to send the wave blocking prompt signal.

[0063] In addition, the desaturation detection module 4 can be specifically connected to the collector of the IGBT, and considering the requirements of device application safety and current reverse protection in actual applications, an eleventh resistor R17 and a second diode D2 can be set between the desaturation detection module 4 and the collector of the IGBT. Figure 2 As stated.

[0064] In summary, the present application provides a shutdown device, which reduces the voltage stress of the target controllable switch through the above-mentioned three-step shutdown control scheme, avoids damage to the target controllable switch as much as possible, and realizes reliable shutdown of the target controllable switch under large inductance and large current conditions. In practical applications, it is beneficial to replace the busbar copper bus with other low-cost materials, which helps to reduce costs.

[0065] Based on the above embodiment:

[0066] As a preferred embodiment, the delay module 5 includes a first controllable switch Q8, a first resistor R14 and a first capacitor C6;

[0067] One end of the first resistor R14 is connected to the first power supply and the desaturation detection module 4, and the other end of the first resistor R14 is connected to the first end of the first controllable switch Q8 and one end of the first capacitor C6 respectively, and the common end of the connected ends is connected to the protection end of the driving module 2;

[0068] The second end of the first controllable switch Q8 is connected to the other end of the first capacitor C6 and the common end of the connections is grounded. The control end of the first controllable switch Q8 is connected to the desaturation detection module 4.

[0069] The first controllable switch Q8 is used to turn on when receiving a stop signal; and turn off when receiving a first turn-on signal, so that the first capacitor C6 starts to charge, and then feeds back a first prompt signal to the driving module 2 when the terminal voltage of the first capacitor C6 reaches a preset voltage threshold.

[0070] In this embodiment, the circuit configuration of the delay module 5 is given. The specific connection method is described in the above text and Figure 2 In addition, the first controllable switch Q8 includes but is not limited to Figure 2 The NPN transistor shown has a base as the control end of the first controllable switch Q8, an emitter as the second end of the first controllable switch Q8, and a collector as the first end of the first controllable switch Q8.

[0071] In addition, considering the safety requirements of the device in practical applications, the delay module 5 may further include a twelfth resistor R16, which is connected in parallel with the first capacitor C6. Figure 2 shown.

[0072] As a preferred embodiment, the desaturation detection module 4 includes a second switch module 41, a second resistor R11, a second capacitor C3, a first voltage stabilizing diode Z3 and a second controllable switch Q7;

[0073] The control end of the second switch module 41 is connected to the output end of the driving module 2. The first end of the second switch module 41 is respectively connected to one end of the second capacitor C3 and the first end of the second controllable switch Q7, and the common end of the connections is grounded. The second end of the second switch module 41 is respectively connected to one end of the second resistor R11, one end of the first resistor R14, the second end of the second controllable switch Q7, the soft shutdown module 1, and the control end of the first controllable switch Q8. The third end of the second switch module 41 is respectively connected to the other end of the second resistor R11, the other end of the second capacitor C3, the cathode of the first Zener diode Z3, and the target controllable switch; the anode of the first Zener diode Z3 is connected to the control end of the second controllable switch Q7.

[0074] The second switch module 41 is configured to be turned off when the driving module 2 outputs a driving signal for controlling the target controllable switch to be turned on, and to be turned on when the driving module 2 outputs a negative pressure signal;

[0075] The first voltage stabilizing diode Z3 is used to turn on the second controllable switch Q7 when the target controllable switch is in the desaturation working state, and then send a first turn-on signal to the delay module 5 and a second turn-on signal to the soft shutdown module 1, and turn off when the target controllable switch is in the non-desaturation working state to turn off the second controllable switch Q7.

[0076] In this embodiment, the circuit structure of the desaturation detection module 4 is provided. The specific connection method is described in the above text and Figure 2 It is also necessary to note that please refer to Figure 2 The second controllable switch Q7 includes but is not limited to Figure 2 The NPN transistor shown has a base as the control end of the second controllable switch Q7, an emitter as the first end of the second controllable switch Q7, and a collector as the second end of the second controllable switch Q7.

[0077] In addition, considering the safety requirements of device applications in actual applications, the desaturation detection module 4 may further include a thirteenth resistor R13, one end of the thirteenth resistor R13 is respectively connected to the second end of the second controllable switch Q7, the soft shutdown module 1 and the delay module 5, and the other end of the thirteenth resistor R13 is respectively connected to the second end of the second switch module 41, one end of the second resistor R11 and the delay module 5. For details, please refer to Figure 2 shown.

[0078] As a preferred embodiment, the second switch module 41 includes a third controllable switch Q5 and a fourth controllable switch Q6;

[0079] The control end of the third controllable switch Q5 serves as the control end of the second switch module 41. The first end of the third controllable switch Q5 is connected to the control end of the fourth controllable switch Q6, and their common end serves as the second end of the second switch module 41. The second end of the third controllable switch Q5 is connected to the first end of the fourth controllable switch Q6, and their common end serves as the first end of the second switch module 41. The second end of the fourth controllable switch Q6 serves as the third end of the second switch module 41.

[0080] The third controllable switch Q5 is configured to be turned on when the driving module 2 outputs a driving signal, and turned off when the driving module 2 outputs a negative pressure signal;

[0081] The fourth controllable switch Q6 is configured to be turned off when the third controllable switch Q5 is turned on, and to be turned on when the third controllable switch Q5 is turned off.

[0082] In this embodiment, the circuit structure of the second switch module 41 is given. The specific connection method is shown in the above text diagram and Figure 2 It should also be noted that the third controllable switch Q5 includes but is not limited to the following: Figure 2 The MOS transistor shown in FIG. 1 is a MOS transistor, the gate of the MOS transistor serves as the control terminal of the third controllable switch Q5, the source of the MOS transistor serves as the second terminal of the third controllable switch Q5, and the drain of the MOS transistor serves as the first terminal of the third controllable switch Q5; the fourth controllable switch Q6 includes but is not limited to the following Figure 2 The NPN transistor shown has a base as the control end of the fourth controllable switch Q6, an emitter as the first end of the fourth controllable switch Q6, and a collector as the second end of the fourth controllable switch Q6.

[0083] In addition, the second switch module 41 may further include a fourteenth resistor R3 and a fifteenth resistor R9, one end of the fourteenth resistor R3 serves as the first end of the second switch module 41, and the other end of the fourteenth resistor R3 is connected to the control end of the third controllable switch Q5; one end of the fifteenth resistor R9 is connected to the first end of the third controllable switch Q5 and the control end of the fourth controllable switch Q6, and the other end of the fifteenth resistor R9 serves as the second end of the second switch module 41.

[0084] As a preferred embodiment, the soft shut-off device is further connected to the control module;

[0085] The control module is also used to send a first shutdown signal to the soft shutdown module 1 to shut down the soft shutdown module 1 when it is determined that the output current of the target controllable switch is not overcurrent and is in a non-desaturation working state; send a third conduction signal to the soft shutdown module 1 to turn on the soft shutdown module 1 when it is determined that the output current is overcurrent and is in a non-desaturation working state, and maintain the output of the drive signal for controlling the conduction of the target controllable switch within a third preset time length to turn on the first switch module 3, so that the target controllable switch is soft-shut down based on the conduction voltage of the soft shutdown module 1; and send a wave-sealing signal to the drive module 2 when the third preset time length is reached to stop the signal output of the drive module 2 and turn off the first switch module 3, so that the target controllable switch is wave-sealed and shut down.

[0086] In this embodiment, processing logic for when an overcurrent occurs and when an overcurrent does not occur when the output current of the target controllable switch is in a non-de-saturation working state is further provided. It is understandable that when it is determined that the output current of the target controllable switch is overcurrent, if the normal turn-on and turn-off logic described in the above embodiment is still executed, the target controllable switch will be damaged due to the excessive voltage stress it faces. Therefore, it is designed that in this case, the control module controls the soft-off module 1 to turn on. Since the control module is outputting a drive signal for controlling the turn-on of the target controllable switch at this time, the drive signal is kept output within a third preset time period, so that the target controllable switch is soft-off based on the turn-on voltage of the soft-off module 1 within the third preset time period. It should be noted that the soft shutdown here can be understood as controlling the target controllable switch to turn off slowly, that is, reducing the turn-off speed of the target controllable switch to avoid generating overvoltage; and when the third preset time period is reached, a blocking signal is sent to the driver module 2 to stop the driver module 2 from outputting the signal and turn off the first switch module 3, so that the target controllable switch is blocked. The setting of the third preset time period avoids the influence of direct blocking shutdown on soft shutdown and ensures that there is sufficient time for soft shutdown to be executed.

[0087] It should be noted that the third preset time length includes but is not limited to 500 nanoseconds, and can be set according to actual needs and is not particularly limited here.

[0088] As a preferred embodiment, the soft shutdown module 1 includes a controllable switch module 11, a sixth controllable switch Q2 and a third voltage stabilizing diode Z1;

[0089] The control end of the controllable switch module 11 is connected to the control module, the first end of the controllable switch module 11 is connected to the control end of the sixth controllable switch Q2 and the desaturation detection module 4, the second end of the controllable switch module 11 is connected to the first end of the sixth controllable switch Q2, and the common end of the connections is connected to the ground end;

[0090] The second end of the sixth controllable switch Q2 is connected to the anode of the third voltage stabilizing diode Z1, and the cathode of the third voltage stabilizing diode Z1 is connected to the first switch module 3 and the driving module 2 respectively;

[0091] The controllable switch module 11 is configured to be turned off upon receiving a first turn-off signal and turned on upon receiving a third turn-on signal;

[0092] The sixth controllable switch Q2 is configured to be turned on when the controllable switch module 11 is turned on and / or receives the second turn-on signal, so as to turn on the third voltage regulator diode Z1; and to be turned off when the controllable switch module 11 is turned off and does not receive the second turn-on signal, so as to turn off the third voltage regulator diode Z1.

[0093] In this embodiment, the circuit structure of the soft shutdown module 1 is provided as described above. Figure 2 It should be noted that the sixth controllable switch Q2 includes but is not limited to the following: Figure 2 The PNP transistor shown in FIG. 1 has a base serving as the control end of the sixth controllable switch Q2, an emitter serving as the second end of the sixth controllable switch Q2, and a collector serving as the first end of the sixth controllable switch Q2. Furthermore, considering the requirements of device application safety and current reverse protection in practical applications, the soft shutdown module 1 may further include an eighth resistor R6 and a first diode D1. One end of the eighth resistor R6 is connected to the first end of the controllable switch module 11, and the other end of the eighth resistor R6 is connected to the base of the PNP transistor. The cathode of the first diode D1 is connected to the cathode of the third voltage regulator diode Z1, and the anode of the first diode D1 is connected to the first switch module 3, etc.

[0094] As a preferred embodiment, the controllable switch module 11 includes an optical coupler PC1 and a seventh controllable switch Q1;

[0095] The anode of the light-emitting diode of the optical coupler PC1 serves as the control terminal of the controllable switch module 11, and the cathode of the light-emitting diode is grounded; the emitter of the phototransistor of the optical coupler PC1 is connected to the control terminal of the seventh controllable switch Q1, and the collector of the phototransistor is connected to the second power supply;

[0096] The first end of the seventh controllable switch Q1 serves as the first end of the controllable switch module 11, and the second end of the seventh controllable switch Q1 serves as the second end of the first controllable switch module Q8;

[0097] The light emitting diode is configured to be turned on upon receiving the third on-signal to turn on the phototransistor and thereby turn on the seventh controllable switch Q1; and turned off upon receiving the first off-signal to turn off the phototransistor and thereby turn off the seventh controllable switch Q1.

[0098] In this embodiment, the controllable switch module 11 may include an optical coupler PC1 and a seventh controllable switch Q1. The specific circuit connection method is described in the above text. Figure 2 It should be noted that, in addition to the circuit designed by the optocoupler PC1 described above, the controllable switch module 11 here can also be a transformer isolation circuit, a bootstrap circuit, a digital isolator, etc., which is not particularly limited here.

[0099] It should also be noted that if Figure 2 As shown, the second power supply may be a +15V DC power supply; the seventh controllable switch Q1 includes but is not limited to a MOS transistor, the gate of the MOS transistor serving as the control terminal of the seventh controllable switch Q1, the source of the MOS transistor serving as the first terminal of the seventh controllable switch Q1, and the drain of the MOS transistor serving as the second terminal of the seventh controllable switch Q1; the controllable switch module 11 may further include a ninth resistor R4, a tenth resistor R5, and a fifth capacitor C2, one end of the ninth resistor R4 being connected to the emitter of the phototransistor, the other end of the ninth resistor R4 being connected to the gate of the MOS transistor, one end of the fifth capacitor C2, and one end of the tenth resistor R5, respectively; the source of the MOS transistor, the other end of the tenth resistor R5, and the other end of the fifth capacitor C2 being connected, and the common end of the connections being grounded.

[0100] As a further explanation of the principles of the above embodiment:

[0101] When the control module normally controls the target controllable switch (i.e., the IGBT labeled TV7 in the figure) to turn on, a drive signal is output to the ANODE terminal of the driver chip PC2, and the VOUT terminal of the driver chip PC2 keeps outputting a high voltage of +15V, the NPN transistor Q4 is turned on, the PNP transistor Q3 is turned off, and the target controllable switch is turned on;

[0102] When it is determined that the output current of the target controllable switch is not overcurrent and is in a non-desaturated working state, the control module outputs a low level to the anode of the light-emitting diode of the optocoupler PC1, the phototransistor of the optocoupler PC1 is turned off, the MOS tube is turned off, and the sixth controllable switch Q2 and the third voltage regulator diode Z1 are both turned off (that is, the soft shutdown module 1 is controlled to be turned off);

[0103] When it is determined that the output current of the target controllable switch is overcurrent and is in a non-de-saturation working state, the control module outputs a high level to the anode of the light-emitting diode, the phototransistor is turned on, the MOS tube is turned on, the sixth controllable switch Q2 is turned on, and the third voltage regulator diode Z1 is turned on (that is, the control soft shutdown module 1 is turned on). At this time, the VOUT terminal of the driver chip PC2 maintains the output of the +15V high voltage, but due to the conduction of the sixth controllable switch Q2 and the third voltage regulator diode Z1, the base of the NPN transistor Q4 and the base of the PNP transistor Q3 will be connected to the COM terminal (that is, the ground terminal) through the first diode D1, the third voltage regulator diode Z1 and the sixth controllable switch Q2. When the voltage at the base of the NPN transistor Q4 and the PNP transistor Q3 is regulated by the breakdown voltage of the third Zener diode Z1, the base voltages of the NPN transistor Q4 and the PNP transistor Q3 will also determine the gate drive voltage of the target controllable switch. In this way, by changing the breakdown voltage of the third Zener diode Z1, the target controllable switch can be soft-turned off with different voltages. After the third preset time is reached, the control module sends a blocking signal to the ANODE terminal of the driver chip PC2, the VOUT terminal of the driver chip PC2 stops outputting signals, the NPN transistor Q4 and the PNP transistor Q3 are both turned off, and the target controllable switch is immediately turned off.

[0104] More specifically, a further explanation of the circuit structure principle given in the above embodiment is given:

[0105] When the target controllable switch is in a non-desaturation operating state and not experiencing overcurrent, the Vce voltage of the IGBT when it is turned on is approximately 2V. The breakdown voltage of the first Zener diode Z3 is 9.1V. The Vout pin of the driver chip PC2 outputs a high level of +15V, turning on the IGBT. Simultaneously, this high level output of +15V turns on the third controllable switch Q5 via the fourteenth resistor R3. After the third controllable switch Q5 is turned on, the fourth controllable switch Q6 is turned off. The +15V voltage output by the first power supply charges the second capacitor C3 via the second resistor R11. However, since the Vce voltage of the IGBT is approximately 2V when it is turned on, the terminal voltage of the second capacitor C3 is clamped to 2V + the forward voltage drop of the second diode D2. This voltage is much lower than the breakdown voltage of the first Zener diode Z3, turning off the second controllable switch Q7. This ensures that the desaturation detection module 4 does not affect the on / off control of the soft shutdown module 1 when the target controllable switch is in a non-desaturation operating state.

[0106] When the second controllable switch Q7 is turned off, the first controllable switch Q8 is turned on, thereby discharging the terminal voltage of the first capacitor C6 to 0V. The protection terminal of the driver chip PC2 does not receive the first prompt signal, and the IGBT can achieve normal conduction control. Similarly, when the target controllable switch is controlled to be turned off, the Vout pin of the driver chip PC2 outputs a low level of -10V (or directly blocks the wave), the third controllable switch Q5 is turned off, and the fourth controllable switch Q6 is turned on, then the voltage across the second capacitor C3 is discharged to 0V, the second controllable switch Q7 remains off, and the first controllable switch Q8 is turned on, thereby still discharging the terminal voltage of the first capacitor C6 to 0V, the protection terminal of the driver chip PC2 does not receive the first prompt signal, and the IGBT can achieve normal shutdown control. It can be seen that the addition of the desaturation detection module 4 and the delay module 5 does not affect the normal conduction and shutdown control logic when the target controllable switch is in a non-desaturation working state and is not overcurrent.

[0107] Furthermore, when the output current of the IGBT reaches the desaturation operating current and is in the desaturation operating state, the Vout pin of the driver chip PC2 maintains the output of +15V high level, the third controllable switch Q5 is turned on, the fourth controllable switch Q6 is turned off, and the +15V voltage output by the first power supply is charged to the second capacitor C3 through the second resistor R11. Since the Vce voltage of the IGBT increases in the desaturation operating state, it will not clamp the voltage across the second capacitor C3. When the voltage across the second capacitor C3 is greater than the breakdown voltage of the first Zener diode Z3, the first Zener diode Z3 is broken down, and the second controllable switch Q5 is turned on. When switch Q7 is turned on, the sixth controllable switch Q2 is turned on, and the bases of the NPN transistor Q4 and the PNP transistor Q3 in the first switch module 3 are connected to the COM terminal (i.e., the ground terminal) through the first diode D1, the third zener diode Z1, and the sixth controllable switch Q2. The base voltages of the NPN transistor Q4 and the PNP transistor Q3 depend on the breakdown voltage of the third zener diode Z1. Thus, by changing the breakdown voltage of the third zener diode Z1, the target controllable switch can be softly turned off with different voltages, thereby achieving the first step of turning off the IGBT during desaturation, i.e., soft shutdown.

[0108] After the second controllable switch Q7 is turned on, the first controllable switch Q8 is turned off, and the +15V voltage output by the first power supply charges the first capacitor C6 through the first resistor R14. When the terminal voltage across the first capacitor C6 reaches the preset voltage threshold, a first prompt signal is fed back to the protection terminal of the driver module 2. Specifically, the driver chip PC2 has a DESAT protection mechanism. The DESAT protection mechanism is triggered when the DESAT terminal receives an electrical signal greater than 6.5V, and then feeds back a wave blocking prompt signal to the control module through its FAULT terminal. Here, when the terminal voltage across the first capacitor C6 is higher than 6.5V (i.e., the preset voltage threshold), the driver module 2 is triggered. The DESAT protection mechanism of driver chip PC2 causes the Vout pin of driver chip PC2 to output a negative voltage signal, i.e., -10V. The base voltage of NPN transistor Q4 and PNP transistor Q3 changes from a voltage value related to the conduction voltage of third Zener diode Z1 to -10V. The IGBT will be turned off at -10V, achieving the second negative voltage shutdown step. It can be understood that the first preset duration described in the above embodiment is essentially the duration for the terminal voltage of first capacitor C6 to reach the preset voltage threshold as it continues to charge, that is, the duration for the +15V voltage to charge first capacitor C6 through first resistor R14 and reach 6.5V. Finally, after receiving the wave blocking prompt signal, the control module sends the wave blocking signal after a second preset duration to immediately and completely shut down the target controllable switch.

[0109] As a preferred embodiment, the shutdown device further includes a hardware overcurrent detection module 6;

[0110] The hardware overcurrent detection module 6 is connected to the current acquisition module, the soft shutdown module 1 and the control module respectively, and is used to control the soft shutdown module 1 to turn on when detecting that the output current of the target controllable switch acquired by the current acquisition module is overcurrent and is in a non-desaturation working state, and send a third prompt signal indicating an overcurrent fault to the control module, so that the control module sends a wave sealing signal to the driving module 2 after a delay of a third preset time after receiving the third prompt signal.

[0111] In this embodiment, in order to achieve reliable and rapid triggering of the soft shutdown module 1 when the output current of the target controllable switch is overcurrent, a dual triggering logic of hardware soft shutdown logic and software soft shutdown logic is designed. Specifically, the shutdown device may also include a hardware overcurrent detection module 6, which includes but is not limited to the hardware overcurrent detection circuit inherent in the power converter, and is not specifically limited here; the current acquisition module is a module for real-time acquisition of the output current of the IGBT. In actual application, for ease of operation, taking a three-phase power converter as an example, please refer to Figure 3 Whether the output current of IGBT is overcurrent can be further understood as Figure 3 Is there any overcurrent on any of the three-phase input terminals of the motor M? Figure 3 The current acquisition point of the current acquisition module is further represented by the reference symbol A, and the current acquisition module can collect the current value at the detection point A as a subsequent output current determination benchmark (limited by the focus of the picture display, Figure 3 Only the position diagram of the collection detection point A of the current collection module is emphasized. As for the connection diagram of the current collection module, the control module and the hardware overcurrent detection module 64, it can be implemented according to the above description).

[0112] From the perspective of software soft shutdown logic, the control module is also connected to the current acquisition module to receive the output current sent by the current acquisition module. When it is determined that the output current is greater than the preset current threshold, it is determined that the output current is overcurrent, and then a series of soft shutdown logics such as controlling the soft shutdown module 1 to turn on are executed. These will not be elaborated here, and there is no special limitation on the specific value of the preset current threshold.

[0113] From the perspective of hardware soft-shutdown logic, the output end of the hardware overcurrent detection module 6 is connected to the soft-shutdown module 1 and can directly detect whether the output current is overcurrent. If so, the hardware overcurrent detection module 6 directly controls the soft-shutdown module 1 to conduct and feeds back the third prompt signal to the control module. After receiving the third prompt signal, the control module sends a wave-sealing signal to the driver module 2 after a third preset delay, so that the driver module 2 stops signal output and turns off the first switch module 3, so that the target controllable switch performs a wave-sealing shutdown. Relying on the above-mentioned dual trigger logic, the execution of the soft-shutdown solution in this application is guaranteed reliably and timely.

[0114] As a preferred embodiment, the desaturation detection module 4 includes a third switch module 42, a third resistor R18, a fourth resistor R19, a third capacitor C8, a comparison module U1, a second voltage stabilizing diode Z4 and a fifth controllable switch Q9;

[0115] The control end of the third switch module 42 is connected to the output end of the driving module 2. The first end of the third switch module 42 is respectively connected to one end of the third capacitor C8, the anode of the second voltage-stabilizing diode Z4, and the first end of the fifth controllable switch Q9, and the common end of the connections is grounded. The second end of the third switch module 42 is respectively connected to one end of the third resistor R18, one end of the fourth resistor R19, the output end of the comparison module U1, the control end of the first controllable switch Q8, one end of the first resistor R14, and the control end of the fifth controllable switch Q9. The third end of the third switch module 42 is respectively connected to the other end of the third capacitor C8, the first input end of the comparison module U1, the other end of the third resistor R18, and the target controllable switch.

[0116] The other end of the fourth resistor R19 is connected to the cathode of the second voltage stabilizing diode Z4 and the second input end of the comparison module U1 respectively; the second end of the fifth controllable switch Q9 is connected to the soft shutdown module 1;

[0117] The third switch module 42 is configured to be turned off when the driving module 2 outputs a driving signal for controlling the target controllable switch to be turned on, and to be turned on when the driving module 2 outputs a negative pressure signal; the comparison module U1 is configured to send a first turn-on signal to the delay module 5 when the target controllable switch is in a desaturated operating state, and turn on the fifth controllable switch Q9 to send a second turn-on signal to the soft shutdown module 1; and send a stop signal to the delay module 5 when the target controllable switch is in a non-desaturated operating state, and turn off the fifth controllable switch Q9.

[0118] Please refer to Figure 4 , Figure 4 This is a schematic diagram of the structure of another shutdown device provided by the present invention. In this embodiment, the circuit structure of the desaturation detection module 4 is given, and the specific connection method is shown in the above text diagram and Figure 4 In addition, the third switch module 42 includes but is not limited to the same circuit structure as the second switch module 41; the fifth controllable switch Q9 includes but is not limited to the following: Figure 4 The PNP transistor shown in FIG. 1 is a PNP transistor, the base of which serves as the control terminal of the fifth controllable switch Q9, the emitter of which serves as the second terminal of the fifth controllable switch Q9, and the collector of which serves as the first terminal of the fifth controllable switch Q9; the comparison module U1 includes but is not limited to the following: Figure 4 The comparator shown may also be an operational amplifier circuit in other forms.

[0119] In addition, considering the device application safety requirements in actual applications, the desaturation detection module 4 may further include a sixth capacitor C9, a sixteenth resistor R20, and a third diode D3, such as Figure 4 As shown, the sixth capacitor C9 is arranged in parallel with the second voltage zener diode Z4, one end of the sixteenth resistor R20 is respectively connected to the second end of the third switch module 42, one end of the third resistor R18, one end of the fourth resistor R19 and the delay module 5, the other end of the sixteenth resistor R20 is respectively connected to the output end of the comparison module U1, the cathode of the third diode D3 and the delay module 5, and the anode of the third diode D3 is connected to the control end of the fifth controllable switch Q9.

[0120] More specifically, when the desaturation detection module 4 is the above embodiment, a further explanation of the circuit structure principle is given:

[0121] In the target controllable switch, i.e. Figure 4When the IGBT labeled TV7 in the figure is in a non-desaturated operating state and not experiencing overcurrent, the Vce voltage of the IGBT when it is turned on will be approximately 2V. The Vout pin of the driver chip PC2 outputs a high level of +15V, turning on the IGBT. Simultaneously, the high level output of +15V turns on the third controllable switch Q5 via the fourteenth resistor R3, turning off the fourth controllable switch Q6. The +15V voltage output by the first power supply charges the third capacitor C8 via the third resistor R18. Since the Vce voltage is approximately 2V when the IGBT is turned on, the terminal voltage of the third capacitor C8 is clamped, and the terminal voltage of the third capacitor C8 is much lower than the terminal voltage of the second Zener diode Z4. The comparison module U1 then outputs a high level, turning off the fifth controllable switch Q9. This ensures that the desaturation detection module 4 does not affect the on / off control of the soft shutdown module 1 when the target controllable switch is in a non-desaturated operating state.

[0122] When the fifth controllable switch Q9 is turned off, the first controllable switch Q8 is turned on, discharging the terminal voltage of the first capacitor C6 to 0V. The protection terminal of the driver chip PC2 does not receive the first prompt signal, and the IGBT can achieve normal conduction control. When the target controllable switch is controlled to be turned off, the Vout pin of the driver chip PC2 outputs a low level of -10V (or directly blocks the wave), then the third controllable switch Q5 is turned off, and the fourth controllable switch Q6 is turned on, then the voltage across the third capacitor C8 is discharged to 0V, the fifth controllable switch Q9 remains off, and the first controllable switch Q8 remains on, thereby still causing the terminal voltage of the first capacitor C6 to be discharged to 0V. The protection terminal of the driver chip PC2 does not receive the first prompt signal, and the IGBT can achieve normal shutdown control. It can be seen that the addition of the desaturation detection module 4 and the delay module 5 does not affect the normal conduction and shutdown control logic when the target controllable switch is in a non-desaturation working state and is not overcurrent.

[0123] When the output current of the IGBT reaches the desaturation operating current and enters the desaturation operating state, the Vout pin of the driver chip PC2 maintains a high output voltage of +15V, the third controllable switch Q5 is turned on, and the fourth controllable switch Q6 is turned off. The +15V voltage output by the first power supply charges the third capacitor C8 through the third resistor R18. When the IGBT is in the desaturation operating state, the Vce voltage increases and does not clamp the voltage across the third capacitor C8. When the voltage across the third capacitor C8 is greater than the terminal voltage of the second Zener diode Z4, the comparison module U1 outputs a low voltage, the fifth controllable switch Q9 and the sixth controllable switch Q2 are turned on, and the base voltages of the NPN transistor Q4 and the PNP transistor Q3 depend on the breakdown voltage of the third Zener diode Z1, thereby determining the gate drive voltage of the target controllable switch. value, thereby achieving the first step of IGBT shutdown in the desaturation state, i.e., soft shutdown; after the fifth controllable switch Q9 is turned on, the first controllable switch Q8 is turned off, and the +15V voltage output by the first power supply charges the first capacitor C6 through the first resistor R14. When the terminal voltage across the first capacitor C6 reaches the preset voltage threshold, a first prompt signal is fed back to the protection terminal of the driver module 2. That is, when the terminal voltage across the first capacitor C6 exceeds 6.5V, the DESAT protection mechanism of the driver chip PC2 is triggered. The driver chip PC2 outputs -10V, and the base voltage of the NPN transistor Q4 and the PNP transistor Q3 changes from the voltage value related to the conduction voltage of the third voltage regulator diode Z1 to -10V. The IGBT will be turned off at -10V, which is the second step of IGBT shutdown in the desaturation state, i.e., negative voltage shutdown. Finally, after receiving the wave blocking prompt signal, the control module sends a wave blocking signal after a second preset time delay to immediately and completely shut down the target controllable switch.

[0124] The present invention also provides a power conversion device, comprising a power conversion circuit and a switch driving device, and further comprising the shutoff device as described above;

[0125] The power conversion circuit includes a plurality of target controllable switches, each of which is connected to a switch driving device and a shutoff device.

[0126] For an introduction to the power conversion device provided in the present invention, please refer to the above-mentioned embodiment of the shutdown device, which will not be repeated here.

[0127] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the embodiments can be referred to each other. For the devices disclosed in the embodiments, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also includes other elements not clearly listed, or also includes elements inherent to such process, article or equipment. In the absence of more restrictions, the elements limited by the sentence "comprise one..." do not exclude the presence of other identical elements in the process, method, article or equipment including the elements.

[0128] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A shut-off device, characterized in that: Applied to a switch driving device, the shutdown device includes a soft shutdown module, a desaturation detection module and a delay module; The soft shutdown module is respectively connected to the first switch module in the switch driving device, the driving module in the switch driving device, the desaturation detection module and the ground terminal, and the first switch module is also connected to the target controllable switch; the driving module is also connected to the control module, the desaturation detection module and the delay module in the switch driving device, and the desaturation detection module is also connected to the first power supply, the delay module and the target controllable switch; The desaturation detection module is configured to send a first conduction signal to the delay module when the target controllable switch is in a desaturation working state, and send a second conduction signal to the soft shutdown module to turn on the soft shutdown module, so that the target controllable switch is soft-shutdown based on the turn-on voltage of the soft shutdown module; and stop sending the second conduction signal and send a stop signal to the delay module when the target controllable switch is in a non-desaturation working state; The delay module is configured to send a first prompt signal to the driving module after a delay of a first preset time upon receiving the first conduction signal, so that the driving module outputs a negative pressure signal after receiving the first prompt signal, so that the target controllable switch performs a negative pressure shutdown based on the negative pressure signal; When the stop signal is received, prohibiting output of the first prompt signal; The control module is configured to, after receiving the wave encapsulation prompt signal sent by the driving module based on the first prompt signal, send a wave encapsulation signal to the driving module after a second preset time delay to cause the driving module to stop signal output and cause the target controllable switch to be turned off by wave encapsulation.

2. The shutoff device according to claim 1, characterized in that The delay module includes a first controllable switch, a first resistor and a first capacitor; One end of the first resistor is connected to the first power supply and the desaturation detection module, and the other end of the first resistor is connected to the first end of the first controllable switch and one end of the first capacitor respectively, and the common end of the connections is connected to the protection end of the driving module; The second end of the first controllable switch is connected to the other end of the first capacitor, and the common end of the connections is grounded. The control end of the first controllable switch is connected to the desaturation detection module. The first controllable switch is used to turn on when receiving the stop signal; and turn off when receiving the first turn-on signal, so that the first capacitor starts charging, and then feeds back a first prompt signal to the driving module when the terminal voltage of the first capacitor reaches a preset voltage threshold.

3. The shutoff device according to claim 2, characterized in that The desaturation detection module includes a second switch module, a second resistor, a second capacitor, a first voltage stabilizing diode and a second controllable switch; The control end of the second switch module is connected to the output end of the driving module, the first end of the second switch module is respectively connected to one end of the second capacitor and the first end of the second controllable switch, and the common end of the connections is grounded, the second end of the second switch module is respectively connected to one end of the second resistor, one end of the first resistor, the second end of the second controllable switch, the soft shutdown module, and the control end of the first controllable switch, the third end of the second switch module is respectively connected to the other end of the second resistor, the other end of the second capacitor, the cathode of the first Zener diode, and the target controllable switch; the anode of the first Zener diode is connected to the control end of the second controllable switch; The second switch module is configured to be turned off when the driving module outputs a driving signal for controlling the target controllable switch to be turned on, and to be turned on when the driving module outputs the negative pressure signal; The first voltage regulator diode is used to turn on the second controllable switch when the target controllable switch is in a desaturated working state, thereby sending a first turn-on signal to the delay module and a second turn-on signal to the soft shutdown module, and turn off the second controllable switch when the target controllable switch is in a non-desaturated working state.

4. The shutoff device according to claim 3, characterized in that The second switch module includes a third controllable switch and a fourth controllable switch; The control end of the third controllable switch serves as the control end of the second switch module, the first end of the third controllable switch is connected to the control end of the fourth controllable switch, and the common end of the connections serves as the second end of the second switch module, the second end of the third controllable switch is connected to the first end of the fourth controllable switch, and the common end of the connections serves as the first end of the second switch module, and the second end of the fourth controllable switch serves as the third end of the second switch module; The third controllable switch is configured to be turned on when the driving module outputs the driving signal, and turned off when the driving module outputs the negative pressure signal; The fourth controllable switch is configured to be turned off when the third controllable switch is turned on, and to be turned on when the third controllable switch is turned off.

5. The shutoff device according to claim 2, characterized in that: The desaturation detection module includes a third switch module, a third resistor, a fourth resistor, a third capacitor, a comparison module, a second voltage stabilizing diode and a fifth controllable switch; The control end of the third switch module is connected to the output end of the driving module. The first end of the third switch module is respectively connected to one end of the third capacitor, the anode of the second voltage stabilizing diode, and the first end of the fifth controllable switch, and the common end of the connections is grounded. The second end of the third switch module is respectively connected to one end of the third resistor, one end of the fourth resistor, the output end of the comparison module, the control end of the first controllable switch, one end of the first resistor, and the control end of the fifth controllable switch. The third end of the third switch module is respectively connected to the other end of the third capacitor, the first input end of the comparison module, the other end of the third resistor, and the target controllable switch. The other end of the fourth resistor is connected to the cathode of the second voltage stabilizing diode and the second input end of the comparison module respectively; the second end of the fifth controllable switch is connected to the soft shutdown module; The third switch module is configured to be turned off when the driving module outputs a driving signal for controlling the target controllable switch to be turned on, and to be turned on when the driving module outputs the negative pressure signal; the comparison module is configured to send a first turn-on signal to the delay module when the target controllable switch is in a desaturation working state, and turn on the fifth controllable switch to send a second turn-on signal to the soft shutdown module; and send a stop signal to the delay module and turn off the fifth controllable switch when the target controllable switch is in a non-desaturation working state.

6. The shutoff device according to any one of claims 2 to 5, characterized in that: The soft shut-off device is also connected to the control module; The control module is further configured to, when determining that the output current of the target controllable switch does not overcurrent and is in a non-de-saturation working state, send a first shutdown signal to the soft shutdown module to shut down the soft shutdown module; when determining that the output current overcurrent occurs and is in a non-de-saturation working state, send a third turn-on signal to the soft shutdown module to turn on the soft shutdown module, and maintain outputting a drive signal for controlling the conduction of the target controllable switch within a third preset time length to turn on the first switch module, so that the target controllable switch is soft-shut down based on the turn-on voltage of the soft shutdown module; and, when the third preset time length is reached, send a wave-blocking signal to the drive module to stop the signal output and turn off the first switch module, so that the target controllable switch is wave-blocked and shut down.

7. The shutoff device according to claim 6, characterized in that The soft shutdown module includes a controllable switch module, a sixth controllable switch and a third voltage stabilizing diode; The control end of the controllable switch module is connected to the control module, the first end of the controllable switch module is connected to the control end of the sixth controllable switch and the desaturation detection module, the second end of the controllable switch module is connected to the first end of the sixth controllable switch, and the common end of the connections is connected to the ground end; The second end of the sixth controllable switch is connected to the anode of the third voltage stabilizing diode, and the cathode of the third voltage stabilizing diode is connected to the first switch module and the driving module respectively; The controllable switch module is configured to be turned off upon receiving the first turn-off signal and turned on upon receiving the third turn-on signal; The sixth controllable switch is configured to be turned on when the controllable switch module is turned on and / or receives the second turn-on signal, so as to turn on the third voltage regulator diode; and to be turned off when the controllable switch module is turned off and does not receive the second turn-on signal, so as to turn off the third voltage regulator diode.

8. The shutoff device according to claim 7, characterized in that: The controllable switch module includes an optical coupler and a seventh controllable switch; The anode of the light-emitting diode of the optocoupler serves as the control terminal of the controllable switch module, and the cathode of the light-emitting diode is grounded; the emitter of the phototransistor of the optocoupler is connected to the control terminal of the seventh controllable switch, and the collector of the phototransistor is connected to the second power supply; The first end of the seventh controllable switch serves as the first end of the controllable switch module, and the second end of the seventh controllable switch serves as the second end of the controllable switch module; The light emitting diode is configured to be turned on upon receiving the third turn-on signal, so as to turn on the phototransistor and thereby turn on the seventh controllable switch; and to be turned off upon receiving the first turn-off signal, so as to turn off the phototransistor and thereby turn off the seventh controllable switch.

9. The shutoff device according to claim 6, characterized in that: The shutdown device also includes a hardware overcurrent detection module; The hardware overcurrent detection module is connected to the current acquisition module, the soft shutdown module and the control module respectively, and is used to control the soft shutdown module to turn on when detecting that the output current of the target controllable switch acquired by the current acquisition module is overcurrent and is in a non-desaturation working state, and send a third prompt signal indicating an overcurrent fault to the control module, so that the control module sends the enclosing signal to the driving module after delaying the third preset time after receiving the third prompt signal.

10. A power conversion device, characterized in that: comprising a power conversion circuit and a switch driving device, and further comprising a shutoff device according to any one of claims 1 to 9; The power conversion circuit includes a plurality of target controllable switches, and each of the target controllable switches is connected to the switch driving device and the shutoff device.

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