Rapid discharging circuit of high-voltage type switching power supply

Abstract

The invention discloses a high-voltage switching power supply rapid discharge circuit, which is applied to the technical field of switching power supplies, and comprises a driving and switching circuit, a discharge module 1, a discharge module 2, a discharge module 3 and a power supply output end, and the discharge module 1, the discharge module 2 and the discharge module 3 are respectively composed of an isolation circuit and a power circuit. A power circuit and an isolation circuit form a discharge module, the driving capability of a discharge signal is enhanced by using a driving and switching circuit, the enhanced discharge signal and power supply are switched to each discharge module, an FD signal is converted into an FDO with stronger driving capability through the driving and switching circuit, and the FDO is output to each discharge module. And the MOS tube / IGBT Q1 made of the silicon carbide material is discharged. Therefore, rapid discharge of a high-voltage machine type power supply can be safely and stably realized, stable switch discharge signals are ensured, the discharge function is realized in the high-voltage switch power supply, and the high-voltage switch power supply is low in cost, small in size and capable of flexibly adapting to power supplies with different rated voltages.

Description

Technical Field

[0001] The invention belongs to the technical field of switching power supplies, and in particular relates to a fast discharge circuit of a high-voltage switching power supply. Background Art

[0002] A switching power supply is a high-frequency power conversion device that converts a voltage level into the voltage or current required by the user through different forms of architecture.

[0003] At present, a Chinese invention with the announcement number of CN107395005B discloses a fast discharge circuit of a filter capacitor of a switching power supply. The existing switching power supply usually has a fast discharge function, so that after the power supply is used up and the output is turned off, the remaining power on the output side is quickly consumed, so as to avoid the residual power being stored at the output end for a long time, which poses a safety hazard to equipment and personnel and causes electric shock accidents. However, the discharge circuit of the existing switching power supply generally consumes the residual power through a low-power MOS tube or IGBT. During the discharge process, there is still voltage on the filter capacitor, and the energy stored can generally only be released slowly, which may still cause the risk of electric shock. If you want to achieve the effect of fast discharge, you must require the discharge tube to withstand the rated input of the power supply output, but the price of the MOS tube / IGBT with a source-drain / collector-emitter withstand voltage of more than 2000V is relatively high, which will undoubtedly greatly increase the cost of the switching power supply. Therefore, the switching power supply model above 2000V is difficult to apply in practice, which reduces the practicality of the switching power supply of this model. Summary of the invention

[0004] The purpose of the present invention is to provide a high-voltage switching power supply fast discharge circuit, which has the advantage of connecting relatively low-voltage silicon carbide MOS tubes in series and using a DCDC isolation module to ensure the stability of the switch discharge signal, so as to achieve the discharge function in the high-voltage switching power supply.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions: a high-voltage machine-type switching power supply fast discharge circuit, including a drive and switching circuit, a discharge module 1, a discharge module 2, a discharge module 3, and a power supply output end. The discharge module 1, the discharge module 2, and the discharge module 3 are all composed of an isolation circuit and a power circuit. The drive and switching circuits are electrically connected to the discharge module 1, the discharge module 2, and the discharge module 3 through VCC, GND, and FDO, respectively. The discharge module 1 and the discharge module 3 are electrically connected to the positive and negative electrodes of the power supply output end through VOH1 and GNDH3, respectively. The discharge module 1 and the discharge module 2 are electrically connected through GNDH1 and VOH2, and the discharge module 2 and the discharge module 3 are electrically connected through GNDH2 and VOH3.

[0006] The above technical solution is adopted to form a discharge module by connecting the power circuit and the isolation circuit, and to increase the rated voltage of the entire discharge circuit by connecting them in series. The driving ability of the discharge signal is enhanced by using the driving and switching circuit, and the enhanced discharge signal and power supply are transferred to each discharge module. The FD signal is then converted into FDO with stronger driving ability and output to each discharge module by the driving and switching circuit. Finally, the on and off of the gate / base of the MOS tube / IGBT Q1 and the size of the discharge current are controlled to meet the requirements of the rated power and discharge time of the MOS tube / IGBT Q1. In this way, the high-voltage machine power supply can be safely and stably discharged quickly, the switch discharge signal is guaranteed to be stable, and the discharge function in the high-voltage switching power supply is achieved. By connecting the lower-voltage silicon carbide MOS tube in series and using the DCDC isolation module to convert VCC into positive voltage VCCH, negative voltage VEEH, and ground line GNDH after isolation, the DCDC isolation module continuously outputs and inputs the filter circuit. Finally, the reverse diode D1 is used to provide protection for VEEH. Not only can stable discharge be achieved, but the use of silicon carbide MOS tubes is low-cost, small in size, and can flexibly adapt to power supplies with different rated voltages.

[0007] The present invention is further configured as follows: the driving and switching circuit includes a driving chip IC7, a wiring terminal P2, a wiring terminal P3, a wiring terminal P4, and a wiring terminal P5; the driving chip IC7 is electrically connected to the wiring terminal P2 through FD; the driving chip IC7 is electrically connected to the wiring terminal P3, the wiring terminal P4, and the wiring terminal P5 through FDO; and the VCC, GND, and FDO of the driving and switching circuit are connected in parallel with the discharge module 1, the discharge module 2, and the discharge module 3.

[0008] By adopting the above technical solution, the driver chip IC7 can output the FD signal as an FDO signal with stronger driving capability, and output it to each discharge module for discharge, thereby improving the discharge performance.

[0009] The present invention is further configured as follows: VCC of the driving and switching circuit is a positive voltage from an auxiliary circuit, GND is a ground line from the auxiliary circuit, and FD is a discharge signal from a control circuit.

[0010] By adopting the above technical solution, the driving capability of the discharge signal can be enhanced and the rated voltage of the entire discharge circuit can be increased.

[0011] The present invention is further configured as follows: the isolation circuit includes a DC-DC high-voltage isolation module U2, one end of the DC-DC high-voltage isolation module U2 is electrically connected to a positive voltage VCC and a ground wire GND, and the other end of the DC-DC high-voltage isolation module U2 is electrically connected to a positive voltage VCCH, a negative voltage VEEH, and an isolation ground wire GNDH.

[0012] By adopting the above technical solution, the DC-DC high-voltage isolation module U2 can convert the VCC input by the driving and switching circuit into positive voltage VCCH, negative voltage VEEH, and isolated ground line GNDH, so as to transfer the enhanced discharge signal and power supply to each discharge module.

[0013] The present invention is further configured as follows: one end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCC and the ground wire GND is also electrically connected to an inductor L1, a capacitor C2, and a capacitor C3, respectively; and one end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCCH, the negative voltage VEEH, and the isolation ground wire GNDH is also electrically connected to a capacitor C4 and a capacitor C5, respectively.

[0014] By adopting the above technical solution, the inductor L1, capacitor C2 and capacitor C3 can be set to provide an input filter circuit for the DC-DC high voltage isolation module U2; and the capacitor C4 and capacitor C5 can be set to provide an output filter circuit for the DC-DC high voltage isolation module U2.

[0015] The present invention is further configured as follows: the withstand voltage value of the DC-DC high voltage isolation module U2 should be ≥ the rated value of the power supply.

[0016] By adopting the above technical solution, the rated voltage of the entire discharge circuit is increased.

[0017] The present invention is further configured as follows: the power circuit includes a high-voltage isolation optocoupler U1 and a wiring terminal P1, one end of the high-voltage isolation optocoupler U1 is electrically connected to a discharge signal FDO and a ground wire GND, the high-voltage isolation optocoupler U1 is electrically connected to the wiring terminal P1 through the discharge signal FDO, and the other end of the high-voltage isolation optocoupler U1 is electrically connected to a positive voltage VCCH and a positive voltage VCCH1.

[0018] By adopting the above technical solution, the discharge module can control the on / off of the VCCH voltage to the gate / base of the MOS tube / IGBT Q1 through the FDO signal, ensuring that the MOS tube / IGBT Q1 will not be turned on by mistake.

[0019] The present invention is further configured as follows: a resistor R4 is electrically connected between the high-voltage isolation optocoupler U1 and the ground wire GND, the high-voltage isolation optocoupler U1 is connected in series with a MOS tube / IGBT Q1 through a positive voltage VCCH1, and a reverse diode D1, a voltage regulator diode DW1, a capacitor C1, a resistor R1, and a resistor R3 are respectively connected in series between the high-voltage isolation optocoupler U1 and the MOS tube / IGBT Q1.

[0020] By adopting the above technical solution, the resistor R3 and the voltage stabilizing diode DW1 are used to adjust the discharge current to meet the requirements of the rated power and discharge time of the MOS tube / IGBT Q1.

[0021] The present invention is further configured as follows: one end of the MOS tube / IGBT Q1 is electrically connected to a negative voltage VEEH, a resistor R2 is electrically connected between the MOS tube / IGBT Q1 and the negative voltage VEEH, and the other end of the MOS tube / IGBT Q1 is electrically connected to an isolation ground wire GNDH.

[0022] By adopting the above technical solution, the MOS tube / IGBT Q1 in each discharge module can be discharged quickly, thereby improving the discharge stability.

[0023] The present invention is further configured as follows: the resistor R1 and the resistor R2 are current limiting resistors, the capacitor C1 is a selectively welded filter capacitor, and the MOS tube / IGBT Q1 is made of silicon carbide.

[0024] By adopting the above technical solution, the MOS tube is processed by using relatively cheap silicon carbide material, thereby ensuring the stable discharge performance of the MOS tube and reducing the cost at the same time.

[0025] In summary, the present invention has the following beneficial effects: 1. The power circuit and the isolation circuit are combined into a discharge module, and the rated voltage of the entire discharge circuit is increased by connecting them in series. The driving capability of the discharge signal is enhanced by the driving and switching circuit, and the enhanced discharge signal and power supply are transferred to each discharge module. The FD signal is then converted into a FDO with stronger driving capability and output to each discharge module through the driving and switching circuit. Finally, the on and off of the gate / base of the MOS tube / IGBT Q1 and the size of the discharge current are controlled to meet the requirements of the rated power and discharge time of the MOS tube / IGBT Q1. In this way, the rapid discharge of the high-voltage power supply can be realized safely and stably, the switch discharge signal can be ensured to be stable, and the discharge function can be realized in the high-voltage switching power supply; 2. By connecting the lower voltage silicon carbide MOS tubes in series and using the DCDC isolation module to convert VCC into positive voltage VCCH, negative voltage VEEH, and isolated ground GNDH, the DCDC isolation module continuously outputs and inputs the filter circuit. Finally, the reverse diode D1 is used to provide protection for VEEH. Not only can stable discharge be achieved, but the use of silicon carbide MOS tubes is low in cost and small in size, and can flexibly adapt to power supplies with different rated voltages. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a high voltage discharge circuit diagram of the present invention; Figure 2 It is the driving and switching circuit diagram of the present invention; Figure 3 is an isolation circuit diagram of the present invention; Figure 4 It is a power circuit diagram of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with the accompanying drawings.

[0028] Embodiment 1: refer to Figure 1 , Figure 2 , Figure 3 , Figure 4A high-voltage switching power supply fast discharge circuit includes a drive and transfer circuit, a discharge module 1, a discharge module 2, a discharge module 3, and a power output terminal. The discharge module 1, the discharge module 2, and the discharge module 3 are all composed of an isolation circuit and a power circuit. The drive and transfer circuits are electrically connected to the discharge module 1, the discharge module 2, and the discharge module 3 through VCC, GND, and FDO, respectively. The discharge module 1 and the discharge module 3 are electrically connected to the positive and negative electrodes of the power output terminal through VOH1 and GNDH3, respectively. The discharge module 1 and the discharge module 2 are electrically connected through GNDH1 and VOH2. The discharge module 2 and The discharge modules 3 are electrically connected through GNDH2 and VOH3; the driving and switching circuit includes a driving chip IC7, a wiring terminal P2, a wiring terminal P3, a wiring terminal P4, and a wiring terminal P5; the driving chip IC7 is electrically connected to the wiring terminal P2 through FD; the driving chip IC7 is electrically connected to the wiring terminal P3, the wiring terminal P4, and the wiring terminal P5 through FDO; the VCC, GND, and FDO of the driving and switching circuit are connected in parallel with the discharge module 1, the discharge module 2, and the discharge module 3; the VCC of the driving and switching circuit is the positive voltage from the auxiliary circuit, the GND is the ground wire from the auxiliary circuit, and the FD is the ground wire from the control circuit. The isolation circuit includes a DC-DC high-voltage isolation module U2, one end of the DC-DC high-voltage isolation module U2 is electrically connected to a positive voltage VCC and a ground line GND, and the other end of the DC-DC high-voltage isolation module U2 is electrically connected to a positive voltage VCCH, a negative voltage VEEH, and an isolation ground line GNDH; the end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCC and the ground line GND is also electrically connected to an inductor L1, a capacitor C2, and a capacitor C3, respectively, and the end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCCH, the negative voltage VEEH, and the isolation ground line GNDH is also respectively Capacitor C4 and capacitor C5 are electrically connected; the withstand voltage of the DC-DC high-voltage isolation module U2 should be ≥ the rated value of the power supply; the power circuit includes a high-voltage isolation optocoupler U1 and a wiring terminal P1, one end of the high-voltage isolation optocoupler U1 is electrically connected to a discharge signal FDO and a ground wire GND, the high-voltage isolation optocoupler U1 is electrically connected to the wiring terminal P1 through the discharge signal FDO, and the other end of the high-voltage isolation optocoupler U1 is electrically connected to a positive voltage VCCH and a positive voltage VCCH1; a resistor R4 is electrically connected between the high-voltage isolation optocoupler U1 and the ground wire GND, and the high-voltage isolation optocoupler U1 is connected in series with a MOS tube / IGBT through the positive voltage VCCH1 Q1, a reverse diode D1, a voltage stabilizing diode DW1, a capacitor C1, a resistor R1, and a resistor R3 are respectively connected in series between the high-voltage isolation optocoupler U1 and the MOS tube / IGBT Q1; one end of the MOS tube / IGBT Q1 is electrically connected to a negative voltage VEEH, a resistor R2 is electrically connected between the MOS tube / IGBT Q1 and the negative voltage VEEH, and the other end of the MOS tube / IGBT Q1 is electrically connected to an isolation ground wire GNDH;Resistors R1 and R2 are current limiting resistors, capacitor C1 is a filter capacitor that can be welded, and MOS tube / IGBT Q1 is made of silicon carbide. ;

[0029] Embodiment 2: refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 , a high-voltage machine type switching power supply fast discharge circuit includes a driving and switching circuit, a discharge module 1, a discharge module 2, a discharge module 3, and a power output end. The discharge module 1, the discharge module 2, and the discharge module 3 are all composed of an isolation circuit and a power circuit. The driving and switching circuits are electrically connected to the discharge module 1, the discharge module 2, and the discharge module 3 through VCC, GND, and FDO, respectively. The discharge module 1 and the discharge module 3 are electrically connected to the positive and negative poles of the power output end through VOH1 and GNDH3, respectively. The discharge module 1 and the discharge module 2 are electrically connected through GNDH1 and VOH2, and the discharge module 2 and the discharge module 3 are electrically connected through GNDH2 and VOH3. The power circuit and the isolation circuit are formed into a discharge module, and the rated voltage of the entire discharge circuit is increased by connecting them in series. The driving and switching circuit is used to enhance the driving capability of the discharge signal, and the enhanced discharge signal and power supply are transferred to each discharge module. Then, the FD signal is converted into a FDO with stronger driving capability and output to each discharge module through the driving and switching circuit. Finally, the on / off of the gate / base of the MOS tube / IGBT Q1 and the size of the discharge current are controlled to meet the requirements of the rated power and discharge time of the MOS tube / IGBT Q1. In this way, the high-voltage power supply can be discharged quickly and safely and stably, and the switch discharge signal can be ensured to be stable, so as to achieve the discharge function in the high-voltage switching power supply. By connecting the lower-voltage silicon carbide MOS tube in series and using the DCDC isolation module to convert VCC into positive voltage VCCH, negative voltage VEEH, and ground line GNDH after isolation, the DCDC isolation module continuously outputs and inputs the filter circuit. Finally, the reverse diode D1 is used to provide protection for VEEH. Not only can stable discharge be achieved, but the use of silicon carbide MOS tubes is low in cost and small in size, and can flexibly adapt to power supplies with different rated voltages.

[0030] refer to Figure 1 , Figure 2The driving and switching circuit includes a driving chip IC7, a wiring terminal P2, a wiring terminal P3, a wiring terminal P4, and a wiring terminal P5. The driving chip IC7 is electrically connected to the wiring terminal P2 through FD, and the driving chip IC7 is electrically connected to the wiring terminal P3, the wiring terminal P4, and the wiring terminal P5 through FDO. The VCC, GND, and FDO of the driving and switching circuit are connected to the discharge module 1, the discharge module 2, and the discharge module 3 in parallel. The driving chip IC7 can output the FD signal as an FDO signal with stronger driving capability, and output it to each discharge module for discharge, thereby improving the discharge performance.

[0031] refer to Figure 2 , the VCC of the driving and switching circuit is the positive voltage from the auxiliary circuit, GND is the ground wire from the auxiliary circuit, and FD is the discharge signal from the control circuit. The driving capability of the discharge signal can be enhanced and the rated voltage of the entire discharge circuit can be increased.

[0032] refer to Figure 1 , Figure 3 The isolation circuit includes a DC-DC high-voltage isolation module U2, one end of which is electrically connected to a positive voltage VCC and a ground line GND, and the other end of which is electrically connected to a positive voltage VCCH, a negative voltage VEEH, and an isolated ground line GNDH. The DC-DC high-voltage isolation module U2 can convert the VCC input by the driving and switching circuits into a positive voltage VCCH, a negative voltage VEEH, and an isolated ground line GNDH, so as to facilitate the enhanced discharge signal and power supply to be transferred to each discharge module.

[0033] refer to Figure 3 The end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCC and the ground line GND is also electrically connected to the inductor L1, the capacitor C2, and the capacitor C3, respectively. The end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCCH, the negative voltage VEEH, and the isolation ground line GNDH is also electrically connected to the capacitor C4 and the capacitor C5. By setting the inductor L1, the capacitor C2, and the capacitor C3, the input filter circuit of the DC-DC high-voltage isolation module U2 can be provided; by setting the capacitor C4 and the capacitor C5, the output filter circuit of the DC-DC high-voltage isolation module U2 can be provided.

[0034] refer to Figure 3 , the withstand voltage of the DC-DC high voltage isolation module U2 should be ≥ the rated value of the power supply. Increase the rated voltage of the entire discharge circuit.

[0035] refer to Figure 1 , Figure 4The power circuit includes a high-voltage isolation optocoupler U1 and a wiring terminal P1. One end of the high-voltage isolation optocoupler U1 is electrically connected to a discharge signal FDO and a ground wire GND. The high-voltage isolation optocoupler U1 is electrically connected to the wiring terminal P1 through the discharge signal FDO. The other end of the high-voltage isolation optocoupler U1 is electrically connected to a positive voltage VCCH and a positive voltage VCCH1. The discharge module can control the on / off of the VCCH voltage to the gate / base of the MOS tube / IGBT Q1 through the FDO signal to ensure that the MOS tube / IGBT Q1 will not be turned on by mistake.

[0036] refer to Figure 4 A resistor R4 is electrically connected between the high-voltage isolation optocoupler U1 and the ground wire GND. The high-voltage isolation optocoupler U1 is connected in series with the MOS tube / IGBT Q1 through the positive voltage VCCH1. A reverse diode D1, a voltage zener diode DW1, a capacitor C1, a resistor R1, and a resistor R3 are also connected in series between the high-voltage isolation optocoupler U1 and the MOS tube / IGBT Q1. The resistor R3 and the voltage zener diode DW1 are used to adjust the size of the discharge current to meet the requirements of the rated power and discharge time of the MOS tube / IGBT Q1.

[0037] refer to Figure 4 One end of the MOS tube / IGBT Q1 is electrically connected to a negative voltage VEEH, a resistor R2 is electrically connected between the MOS tube / IGBT Q1 and the negative voltage VEEH, and the other end of the MOS tube / IGBT Q1 is electrically connected to an isolation ground wire GNDH. This allows the MOS tube / IGBT Q1 in each discharge module to be discharged quickly, thereby improving discharge stability.

[0038] refer to Figure 4 , resistors R1 and R2 are current limiting resistors, capacitor C1 is a filter capacitor for welding, and MOS tube / IGBT Q1 is made of silicon carbide. By using relatively cheap silicon carbide material to process MOS tubes, the discharge performance of MOS tubes can be guaranteed to be stable while reducing costs.

[0039] Brief description of the usage process: First, the power circuit and the isolation circuit are combined into a discharge module. The rated voltage of a single module depends on the source-drain / collector-emitter withstand voltage of the MOS tube / IGBT Q1 in the power circuit, and the rated voltage of the entire discharge circuit is increased by series connection. The driving ability of the discharge signal is enhanced by the driving and switching circuit, and the enhanced discharge signal and power supply are transferred to each discharge module. The rated voltage of the entire discharge circuit depends on the withstand voltage of the MOS tube / IGBT Q1 and the high-voltage isolation optocoupler U1 in the power circuit, and the DC-DC high-voltage isolation module U2 in the isolation circuit; Then the FD signal is output as FDO with stronger driving capability through the driver chip IC7 in the driving and switching circuit. And it is output to each discharge module through the VCC, GND, and FDO parallel wiring terminals; Then, the VCC is converted into positive voltage VCCH, negative voltage VEEH, and ground line GNDH through the DC-DC high voltage isolation module U2 in the isolation circuit. Inductor L1, capacitor C2, and capacitor C3 are used as the input filter circuit of the DC-DC high voltage isolation module U2, and capacitor C4 and capacitor C5 are used as the output filter circuit of the DC-DC high voltage isolation module U2; Finally, the FDO signal is used to control the on / off of the VCCH voltage to the gate / base of the MOS tube / IGBT Q1, so that VEEH provides a negative voltage to ensure that the MOS tube / IGBT Q1 will not be turned on by mistake. The resistor R3 and the Zener diode DW1 are used to adjust the size of the discharge current to meet the rated power and discharge time requirements of the MOS tube / IGBT Q1, and the reverse diode D1 is used to provide protection for VEEH all the way.

[0040] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A high-voltage switching power supply fast discharge circuit, comprising a drive and transfer circuit, a discharge module 1, a discharge module 2, a discharge module 3, and a power supply output end, characterized in that: The discharge module 1, discharge module 2 and discharge module 3 are all composed of an isolation circuit and a power circuit. The driving and switching circuits are electrically connected to the discharge module 1, discharge module 2 and discharge module 3 through VCC, GND and FDO respectively. The discharge module 1 and discharge module 3 are electrically connected to the positive and negative poles of the power output end through VOH1 and GNDH3 respectively. The discharge module 1 and discharge module 2 are electrically connected through GNDH1 and VOH2, and the discharge module 2 and discharge module 3 are electrically connected through GNDH2 and VOH3.

2. The high voltage switching power supply fast discharge circuit according to claim 1, characterized in that: The driving and switching circuit includes a driving chip IC7, a wiring terminal P2, a wiring terminal P3, a wiring terminal P4, and a wiring terminal P5. The driving chip IC7 is electrically connected to the wiring terminal P2 through FD, and the driving chip IC7 is electrically connected to the wiring terminal P3, the wiring terminal P4, and the wiring terminal P5 through FDO. The VCC, GND, and FDO of the driving and switching circuit are connected in parallel with the discharge module 1, the discharge module 2, and the discharge module 3.

3. The high voltage switching power supply fast discharge circuit according to claim 2, characterized in that: The VCC of the driving and switching circuit is a positive voltage from the auxiliary circuit, GND is a ground line from the auxiliary circuit, and FD is a discharge signal from the control circuit.

4. The high voltage switching power supply fast discharge circuit according to claim 1, characterized in that: The isolation circuit includes a DC-DC high-voltage isolation module U2, one end of which is electrically connected to a positive voltage VCC and a ground line GND, and the other end of which is electrically connected to a positive voltage VCCH, a negative voltage VEEH, and an isolation ground line GNDH.

5. The high voltage switching power supply fast discharge circuit according to claim 4, characterized in that: One end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCC and the ground line GND is also electrically connected to the inductor L1, the capacitor C2, and the capacitor C3, and one end of the DC-DC high-voltage isolation module U2 close to the positive voltage VCCH, the negative voltage VEEH, and the isolation ground line GNDH is also electrically connected to the capacitor C4 and the capacitor C5.

6. The high voltage switching power supply fast discharge circuit according to claim 4, characterized in that: The withstand voltage value of the DC-DC high voltage isolation module U2 should be ≥ the rated value of the power supply.

7. The high voltage switching power supply fast discharge circuit according to claim 1, characterized in that: The power circuit includes a high-voltage isolation optocoupler U1 and a wiring terminal P1. One end of the high-voltage isolation optocoupler U1 is electrically connected to a discharge signal FDO and a ground line GND. The high-voltage isolation optocoupler U1 is electrically connected to the wiring terminal P1 through the discharge signal FDO. The other end of the high-voltage isolation optocoupler U1 is electrically connected to a positive voltage VCCH and a positive voltage VCCH1.

8. The high voltage switching power supply fast discharge circuit according to claim 7, characterized in that: A resistor R4 is electrically connected between the high-voltage isolation optocoupler U1 and the ground line GND. The high-voltage isolation optocoupler U1 is connected in series with a MOS tube / IGBT Q1 through a positive voltage VCCH1. A reverse diode D1, a voltage regulator diode DW1, a capacitor C1, a resistor R1, and a resistor R3 are also connected in series between the high-voltage isolation optocoupler U1 and the MOS tube / IGBT Q1, respectively.

9. The high voltage switching power supply fast discharge circuit according to claim 7, characterized in that: One end of the MOS tube / IGBT Q1 is electrically connected to a negative voltage VEEH, a resistor R2 is electrically connected between the MOS tube / IGBT Q1 and the negative voltage VEEH, and the other end of the MOS tube / IGBT Q1 is electrically connected to an isolation ground line GNDH.

10. The high voltage switching power supply fast discharge circuit according to claim 8, characterized in that: The resistor R1 and the resistor R2 are current limiting resistors, the capacitor C1 is a selectively welded filter capacitor, and the MOS tube / IGBT Q1 is made of silicon carbide.

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