High-voltage bleeder circuit, power supply system and control method

Abstract

The invention discloses a high-voltage bleeder circuit, a power supply system and a control method, and relates to the field of switching power supplies, the high-voltage bleeder circuit comprises a primary side control circuit, a secondary side driving circuit and a bleeder execution circuit, the primary side control circuit comprises an isolation optocoupler and a control module, a first end of the isolation optocoupler is connected with a control power supply end, and a second end of the isolation optocoupler is connected with a second end of the control module; the second end is connected with the control module, the third end is connected with the secondary side driving circuit, the control module is further connected with a control signal input end and a first grounding end, the secondary side driving circuit is further connected with a driving power supply end, a second grounding end and the discharge execution circuit, and the discharge execution circuit is further connected with the high-voltage port and the second grounding end; the primary side control circuit is used for outputting a cut-off control signal to the secondary side driving circuit in an abnormal power-off mode; the secondary side driving circuit is used for generating a discharge driving signal to the discharge execution circuit; and the discharge execution circuit is used for discharging the voltage of the high-voltage port to a safe range. According to the scheme, reliable and safe discharge of the voltage of the high-voltage port is realized.

Description

Technical Field

[0001] The present invention generally relates to the technical field of switching power supplies, and particularly relates to a high-voltage discharge circuit, a power supply system and a control method. Background Art

[0002] With the rapid development of power electronic systems, various switching power converters have been widely used in industries, communications, new energy and other fields. Among them, after the system is shut down or abnormally powered off, the high voltage remaining at the DC high-voltage port not only poses a serious threat to the personal safety of subsequent maintenance personnel, but may also affect the normal restart and service life of the equipment. Therefore, achieving the rapid and reliable discharge of the energy at the DC high-voltage port has become the core technical issue for ensuring the safe and stable operation of the system. According to relevant safety standards and design specifications, it is required that the voltage at such a port be rapidly reduced to within 60V after shutdown or abnormal power-off to eliminate potential safety hazards. Currently, for the energy discharge of the DC high-voltage port, the conventional solution is to set up a dedicated discharge circuit. The working principle of a typical discharge circuit is as follows: When the circuit receives a shutdown command or an abnormal power-off occurs and there is still voltage on the bus, the controller receives the discharge command and then detects the port voltage. If the port voltage ≥ 60V, the control signal input terminal DRV1 gives a high-level signal to drive and close the discharge circuit switch Q4, thereby forming an energy discharge path to achieve the rapid discharge of the energy at the high-voltage port; when it is detected that the port voltage < 60V, or the control circuit is powered off, DRV1 outputs a low-level signal to disconnect the discharge circuit switch Q4, and the discharge process ends. This circuit structure is extremely prone to the risk of high voltage penetrating into the low-voltage area in practical applications, and there is also a problem of discharge failure caused by abnormal low-voltage power supply. Summary of the Invention

[0003] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a high-voltage discharge circuit, a power supply system and a control method.

[0004] In a first aspect, the present application provides a high-voltage discharge circuit, which includes: A primary control circuit, a secondary drive circuit, and a discharge execution circuit. The primary control circuit includes an isolation optocoupler and a control module. The first end of the isolation optocoupler is connected to the control power supply terminal, the second end of the isolation optocoupler is connected to one end of the control module, the other end of the control module is respectively connected to the control signal input terminal and the first grounding terminal, the third end of the isolation optocoupler is connected to the secondary drive circuit, the secondary drive circuit is also connected to the drive power supply terminal, the second grounding terminal, and the discharge execution circuit, and the discharge execution circuit is also connected to the high-voltage port and the second grounding terminal; the high-voltage port is used to receive a voltage value greater than a preset threshold. The primary side control circuit is configured to: output a cut-off control signal to the secondary side drive circuit through the isolation optocoupler in an abnormal power-off mode; the abnormal power-off mode includes: the primary side control circuit satisfies the power-off enabling condition and the drive power supply terminal is powered on, and the power-off enabling condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level; The secondary side drive circuit is configured to: generate a discharge drive signal according to the cut-off control signal and send it to the discharge execution circuit; The discharge execution circuit is configured to: discharge the voltage of the high-voltage port to a safe range according to the discharge drive signal.

[0005] In one embodiment, the control module includes: a control switch tube, a first matching resistor-capacitor, and a first resistor; The control signal input terminal is connected to the first end of the first matching resistor-capacitor through the first resistor, the second end of the first matching resistor-capacitor is connected to the gate of the control switch tube, the drain of the control switch tube is connected to the second end of the isolation optocoupler, and the source of the control switch tube and the third end of the first matching resistor-capacitor are both connected to the first grounding terminal.

[0006] In one embodiment, the isolation optocoupler includes: a light-emitting diode and an isolation switch tube; The control signal input terminal is connected to the anode of the light-emitting diode through a second resistor, the cathode of the light-emitting diode is respectively connected to the drain of the control switch tube and the gate of the isolation switch tube, and the source and drain of the isolation switch tube are connected to the secondary side drive circuit.

[0007] In one embodiment, the secondary side drive circuit includes: a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a second matching resistor-capacitor, a third matching resistor-capacitor, a drive diode, and a bridge arm control circuit; The drive power supply terminal is connected to one end of the third resistor, one end of the fourth resistor, and the cathode of the drive diode. The other end of the third resistor is respectively connected to the drain of the isolation switch tube and the second matching resistor-capacitor. The other end of the fourth resistor is connected to the bridge arm control circuit. The bridge arm control circuit is also connected to the second matching resistor-capacitor and the third matching resistor-capacitor. One end of the fifth resistor is connected to the source of the isolation switch tube. The anode of the drive diode is connected to the bridge arm control circuit and the third matching resistor-capacitor through the sixth resistor. The other end of the fifth resistor, the second matching resistor-capacitor, and the third matching resistor-capacitor are all connected to the second grounding terminal.

[0008] In one embodiment, the bridge arm control circuit includes a first bridge arm and a second bridge arm; The drain of the first bridge arm is connected to the other end of the fourth resistor. The gate of the first bridge arm is respectively connected to the second matching resistor-capacitor and the gate of the second bridge arm. The source of the first bridge arm is connected to the drain of the second bridge arm. The source of the second bridge arm is respectively connected to the second matching resistor-capacitor and the third matching resistor-capacitor. The drain of the second bridge arm is further connected to the other end of the sixth resistor and the third matching resistor-capacitor.

[0009] In one embodiment, the discharging execution circuit includes: a discharging circuit switch and a first discharging resistor, a second discharging resistor, a third discharging resistor, and a fourth discharging resistor connected in series in sequence; The third matching resistor-capacitor is connected to the gate of the discharging circuit switch. The first discharging resistor is connected to the high-voltage port. The fourth discharging resistor is connected to the drain of the discharging circuit switch. The source of the discharging circuit switch is connected to the second grounding terminal.

[0010] In one embodiment, the first matching resistor-capacitor, the second matching resistor-capacitor, and the third matching resistor-capacitor each include a capacitor and a resistor connected in parallel with each other.

[0011] In one embodiment, the primary control circuit is further configured to: In the normal control mode, when the control signal input terminal is at a high level, output a conduction control signal to the secondary driving circuit through the isolation optocoupler, so that the secondary driving circuit drives the discharging execution circuit to discharge the voltage of the high-voltage port to a safe range; the normal control mode includes: the control power supply terminal is powered on and the driving power supply terminal is powered on; When the control signal input terminal is at a low level, output a cut-off control signal to the secondary driving circuit through the isolation optocoupler, so that the secondary driving circuit stops discharging the discharging execution circuit.

[0012] In a second aspect, the present application provides a power supply system, including the high-voltage discharging circuit as described in the first aspect above.

[0013] In a third aspect, the present application provides a control method, and the method includes: In the abnormal power-off mode, the primary control circuit outputs a cut-off control signal to the secondary driving circuit through the isolation optocoupler; the abnormal power-off mode includes: the primary control circuit satisfies the power-off enabling condition and the driving power supply terminal is powered on, and the power-off enabling condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level; The secondary driving circuit amplifies the control signal and then generates a discharging driving signal and sends it to the discharging execution circuit; The discharging execution circuit discharges the voltage of the high-voltage port to a safe range according to the discharging driving signal.

[0014] The high-voltage discharge circuit, power supply system and control method provided by the embodiments of the present application. The high-voltage discharge circuit includes: a primary control circuit, a secondary drive circuit, and a discharge execution circuit. The primary control circuit includes an isolation optocoupler and a control module. The first end of the isolation optocoupler is connected to the control power supply terminal, the second end of the isolation optocoupler is connected to one end of the control module, the other end of the control module is respectively connected to the control signal input terminal and the first ground terminal, the third end of the isolation optocoupler is connected to the secondary drive circuit, the secondary drive circuit is also connected to the drive power supply terminal, the second ground terminal, and the discharge execution circuit, and the discharge execution circuit is also connected to the high-voltage port and the second ground terminal; the high-voltage port is used to receive a voltage value greater than a preset threshold. The primary control circuit is used for: in the abnormal power-off mode, outputting a cut-off control signal to the secondary drive circuit through the isolation optocoupler; the abnormal power-off mode includes: the primary control circuit satisfies the power-off enable condition and the drive power supply terminal is powered on, and the power-off enable condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level; the secondary drive circuit is used for: generating a discharge drive signal according to the cut-off control signal and sending it to the discharge execution circuit; the discharge execution circuit is used for: according to the discharge drive signal, discharging the voltage of the high-voltage port to a safe range.

[0015] Compared with the prior art, since the isolation optocoupler is provided in the primary control circuit of the high-voltage discharge circuit provided by the present application, electrical isolation between the primary control circuit and the secondary drive circuit can be achieved, avoiding the risk of high voltage entering the low-voltage area. At the same time, while one end of the secondary drive circuit is connected to the primary control circuit and the other end is connected to the discharge execution circuit, a drive power supply terminal is set to independently supply power to the secondary drive circuit. When the primary control circuit satisfies the power-off enable condition and the drive power supply terminal is powered on, after the secondary drive circuit detects that the isolation optocoupler is cut off, since the drive power supply terminal still has power, it can make the secondary drive circuit default to be conducting and send a discharge drive signal to the discharge execution circuit, realizing the functions of safety isolation and low-voltage locking. Thus, the discharge execution circuit discharges the voltage of the high-voltage port to a safe range, avoiding the risk of discharge failure caused by abnormal low-voltage power supply, ensuring that the voltage of the high-voltage port can be reliably discharged to a safe range (within the safety threshold) under various conditions, and guaranteeing the fast, reliable and safe discharge of the energy of the DC high-voltage port. Description of the Drawings

[0016] By reading the detailed description of the non-restrictive embodiments with reference to the following drawings, other features, purposes and advantages of the present application will become more obvious: Figure 1 It is a schematic structural diagram of a high-voltage discharge circuit in the related art provided by the embodiments of the present application; Figure 2 It is a schematic structural diagram of the high-voltage discharge circuit provided by the embodiments of the present application; Figure 3Schematic diagram of the high-voltage discharge circuit provided by another embodiment of the present application; Figure 4 Schematic diagram of the high-voltage discharge circuit provided by yet another embodiment of the present application; Figure 5 Schematic diagram of the high-voltage discharge circuit provided by still another embodiment of the present application; Figure 6 Schematic flow chart of the control method provided by the embodiment of the present application.

[0017] Description of reference numerals: Primary control circuit - 10; Isolation optocoupler - 11; Control module - 12; Secondary drive circuit - 20; Third resistor - 21; Fourth resistor - 22; Fifth resistor - 23; Sixth resistor - 24; Second matching resistor-capacitor - 25; Third matching resistor-capacitor - 26; Drive diode - 27; Leg control circuit - 28; Discharge execution circuit - 30; Light-emitting diode - 111; Isolation switch tube - 112; Second resistor - 113; First matching resistor-capacitor - 121; First resistor - 122; Control switch tube - 123. Detailed implementation manners

[0018] The present application will be further described in detail below with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the related invention, rather than limiting the invention. Additionally, it should be noted that for the sake of description, only the parts related to the invention are shown in the drawings.

[0019] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below with reference to the drawings and embodiments.

[0020] It can be understood, please refer to Figure 1 as shown Figure 1Schematic diagram of the structure of a high-voltage discharge circuit in the related art. The high-voltage discharge circuit includes: a DC high-voltage port, a control signal terminal, a field-effect transistor Q_4, a ground terminal, a resistor, and a capacitor. The DC high-voltage port can be represented as High voltage, which is the input terminal of the high-voltage power supply that needs to discharge energy in the circuit. The control signal input terminal can be represented as DRV_1. When it is at a high level, it can turn on the field-effect transistor Q_4, thus opening the discharge path; when it is at a low level, it can turn off the field-effect transistor Q_4, and the discharge ends. The ground terminal can be represented as GND_2. Q_4 is usually a field-effect transistor (MOSFET), serving as the switch of the discharge circuit. It conducts under the action of a high-level signal, allowing current to pass through, realizing the discharge of the energy at the DC high-voltage port, and it cuts off under the action of a low-level signal, not allowing current to pass through. The ground terminal provides a loop for the current. Among them, the series resistor between the DC high-voltage port High voltage and Q_4 is used to limit the magnitude of the discharge current and prevent damage to components due to excessive current. The resistor connected between the control signal input terminal DRV_1 and the ground terminal GND_2 plays a current-limiting role to protect the control circuit; the capacitor connected in parallel with it can play roles such as filtering and stabilizing the control signal.

[0021] When the circuit receives a shutdown instruction or an abnormal power-off occurs and there is still voltage on the bus, the controller receives the discharge instruction, checks the port voltage, and judges whether the port voltage is ≥60V. If the port voltage is ≥60V, the control signal input terminal DRV_1 generates a high-level signal to drive and close the discharge circuit switch Q4. At this time, the energy is quickly discharged, thus forming an energy discharge path to realize the rapid discharge of the energy at the high-voltage port; when it is detected that the port voltage <60V, or the control circuit is powered off, the control signal input terminal DRV_1 outputs a low-level signal to disconnect the discharge circuit switch Q4, and the discharge process ends.

[0022] The above scheme has the following defects: First, the control circuit and the high-voltage discharge circuit are not electrically isolated, there is a risk of high voltage intruding into the low-voltage control area, which may cause damage to the low-voltage components in the control circuit and even lead to the failure of the entire system; Second, the discharge process highly depends on the low-voltage power supply powered by DRV_1. Once the low-voltage power supply loses power before the discharge ends, the discharge circuit switch Q4 will be disconnected in advance, resulting in the high-voltage port voltage unable to drop below the safety threshold of 60V, thus unable to meet the safety design requirements and seriously affecting the safety and reliability of the system.

[0023] Based on the above-mentioned deficiencies, the present application provides a high-voltage discharge circuit. Compared with the prior art, since an isolation optocoupler is provided in the primary control circuit of this high-voltage discharge circuit, electrical isolation between the primary control circuit and the secondary drive circuit can be achieved, avoiding the risk of high voltage entering the low-voltage area. And while one end of the secondary drive circuit is connected to the primary control circuit and the other end is connected to the discharge execution circuit, a drive power supply terminal is set to independently supply power to the secondary drive circuit. When the primary control circuit meets the power-off enabling condition and the drive power supply terminal is powered on, after the secondary drive circuit detects that the isolation optocoupler is cut off, since the drive power supply terminal still has power, it can make the secondary drive circuit default to be turned on and send a discharge drive signal to the discharge execution circuit, realizing the functions of safety isolation and low-voltage locking. Thus, the discharge execution circuit discharges the voltage of the high-voltage port to a safe range, avoiding the risk of discharge failure caused by abnormal low-voltage power supply, ensuring that the voltage of the high-voltage port can be reliably discharged to a safe range (within the safety threshold) under various conditions, and guaranteeing the fast, reliable and safe discharge of the energy of the DC high-voltage port.

[0024] Please refer to Figure 2 as shown in Figure 2 FIG. is a schematic structural diagram of the high-voltage discharge circuit provided by an embodiment of the present application. The high-voltage discharge circuit includes: a primary control circuit 10, a secondary drive circuit 20, and a discharge execution circuit 30. The primary control circuit 10 includes an isolation optocoupler 11 and a control module 12. The first end of the isolation optocoupler 11 is connected to the control power supply terminal, the second end of the isolation optocoupler 11 is connected to one end of the control module 12, the other end of the control module 12 is respectively connected to the control signal input terminal and the first grounding terminal, the third end of the isolation optocoupler 11 is connected to the secondary drive circuit 20, the secondary drive circuit 20 is also connected to the drive power supply terminal, the second grounding terminal, and the discharge execution circuit 30, and the discharge execution circuit 30 is also connected to the high-voltage port and the second grounding terminal; the high-voltage port is used to receive a voltage value greater than a preset threshold; The primary control circuit 10 is configured to: output a cut-off control signal to the secondary drive circuit 20 through the isolation optocoupler 11 in an abnormal power-off mode; the abnormal power-off mode includes: the primary control circuit meets the power-off enabling condition and the drive power supply terminal is powered on, and the power-off enabling condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level; the secondary drive circuit 20 is configured to: generate a discharge drive signal according to the cut-off control signal and send it to the discharge execution circuit; the discharge execution circuit 30 is configured to: discharge the voltage of the high-voltage port to a safe range according to the discharge drive signal.

[0025] Specifically, the above-mentioned control power supply terminal is used to supply power to the primary control circuit 10, and the drive power supply terminal is used to supply power to the secondary drive circuit. The control power supply terminal can be VCC_1, and the drive power supply terminal can be VCC_2. By separately supplying power to the primary control circuit and the secondary drive circuit through the control power supply terminal and the drive power supply terminal, it is helpful to improve the stability and safety of the circuit.

[0026] The above-mentioned primary control circuit is used to receive the signal from the control signal input terminal and the electrical energy from the control power supply terminal. By connecting with the secondary drive circuit and using an isolation optocoupler, etc., electrical isolation between the high-voltage area and the low-voltage area is achieved, and the on-off of the secondary circuit is controlled.

[0027] Among them, the primary control circuit receives the control instruction from the control signal input terminal, realizes electrical isolation between the primary (low-voltage side) and the secondary (high-voltage side) through an isolation optocoupler, outputs a control signal, and transmits the control signal to the secondary drive circuit to control the on-off of the secondary drive circuit. The isolation optocoupler can select an optocoupler with a larger withstand voltage value to ensure reliable isolation of the high voltages on the primary and secondary sides, and its response speed also needs to meet the control requirements of the circuit to ensure rapid and accurate transmission of the control signal.

[0028] The above-mentioned secondary drive circuit is used to, when the control power supply terminal on the primary side is in a power-off state or the output of the control signal input terminal is at a low level, use the independent drive power supply terminal in the secondary drive circuit to forcibly generate a discharge drive signal and send it to the discharge execution circuit, ensuring that the high-voltage port receives and responds to the discharge drive signal and continuously discharges to a safe range.

[0029] The above-mentioned discharge execution circuit is used to receive and respond to the signal from the secondary drive circuit. When the signal is a discharge drive signal, it performs a discharge process to discharge the voltage of the high-voltage port to a safe range. This safe range is the interval range that ensures the safety of the high-voltage port voltage.

[0030] The above-mentioned first grounding terminal can be GND_1 and is used for grounding the primary control circuit. The second grounding terminal can be GND_2 and is used for grounding the secondary drive circuit. These two grounding terminals are independent of each other, which can enhance the safety of the circuit.

[0031] In one embodiment, the above-mentioned primary control circuit is further used for: In the normal control mode, when the control signal input terminal is at a high level, it outputs a conduction control signal to the secondary drive circuit through an isolation optocoupler, so that the secondary drive circuit drives the discharge execution circuit to discharge the voltage of the high-voltage port to a safe range; the normal control mode includes: the control power supply terminal is powered on and the drive power supply terminal is powered on.

[0032] When the control signal input terminal is at a low level, a cut-off control signal is output to the secondary side drive circuit through an isolation optocoupler, so that the secondary side drive circuit stops discharging the discharge execution circuit.

[0033] It should be noted that regardless of which one of the control power supply terminal VCC_1 and the drive power supply terminal VCC_2 is powered on first, as long as the drive power supply terminal VCC_2 is powered on, the drive discharge execution circuit automatically enters the discharge state, that is, discharges the voltage of the high-voltage port to a safe range. Among them, the safe range can be custom-set according to actual needs. For example, it can be 0V - 60V.

[0034] As an implementable manner, when the control power supply terminal in the primary side control circuit is in the powered-on state and the drive power supply terminal in the secondary side drive circuit is in the powered-on state, it indicates that it is in the normal control mode at this time. When the control power supply terminal is in the powered-on state, the circuit is in a controllable state. At this time, the control signal input terminal is defaulted to a high level. Before the device is powered on, the discharge execution circuit can be controlled to be disconnected. When the circuit receives a shutdown instruction or abnormal power-off (the bus has power), the controller checks whether the voltage of the high-voltage port is greater than or equal to 60V. When the high-voltage port voltage ≥ 60V, the control signal input terminal outputs a high level, controls the isolation optocoupler to be turned on, and generates a turn-on control signal through the secondary side drive circuit, so that the discharge execution circuit receives and responds to the turn-on control signal, and discharges the voltage of the high-voltage port to a safe range. The controller detects whether the voltage meets the standard. When the high-voltage port voltage < 60V, the control signal input terminal switches to a low level, controls the isolation optocoupler to be turned off, and generates a cut-off control signal through the secondary side drive circuit, so that the discharge execution circuit receives and responds to the cut-off control signal and stops the discharge process.

[0035] As another implementable manner, when the control power supply terminal in the primary side control circuit is in the powered-off state and the drive power supply terminal in the secondary side drive circuit is in the powered-on state, it indicates that it is in the abnormal power-off mode at this time. Since the control power supply terminal is powered off, the control signal input terminal is at a low level, the isolation optocoupler is turned off, and a cut-off control signal is generated. Since the drive power supply terminal in the secondary side drive circuit is in the powered-on state, through the low-voltage locking mechanism of the secondary side drive circuit, a discharge drive signal is generated and sent to the discharge execution circuit. Even if the primary side control circuit fails, the discharge still continues, and the voltage of the high-voltage port is continuously discharged until the safe range (high-voltage port voltage < 60V).

[0036] In this embodiment, since the secondary side drive circuit depends on an independent drive power supply terminal and has nothing to do with the control power supply terminal of the primary side control circuit, it is ensured that the high-voltage discharge does not interrupt during abnormal power-off.

[0037] It can be understood that by setting an isolation optocoupler in the primary control circuit, the electrical connection between the primary side and the secondary side can be isolated, and the primary side and the secondary side adopt independent grounding terminals, so that high voltage cannot invade the low voltage area through the control line or the ground plane. And even when the control power supply terminal is powered off but the drive power supply terminal is still powered on normally, the secondary side drive circuit can discharge the voltage of the high voltage port according to the drive power supply terminal, avoiding the risk of "stopping immediately when powered off", and ensuring that the circuit can reliably achieve high voltage discharge in both the normal control mode and the abnormal power-off mode, taking into account both safety and reliability.

[0038] Compared with the prior art, the high voltage discharge circuit provided by the embodiment of the present application can achieve electrical isolation between the primary control circuit and the secondary side drive circuit by setting an isolation optocoupler in the primary control circuit, avoiding the risk of high voltage stringing into the low voltage area. And while one end of the secondary side drive circuit is connected to the primary control circuit and the other end is connected to the discharge execution circuit, a drive power supply terminal is set to independently supply power to the secondary side drive circuit. When the primary control circuit meets the power-off enable condition and the drive power supply terminal is powered on, after the secondary side drive circuit detects that the isolation optocoupler is cut off, since the drive power supply terminal still has power, it can make the secondary side drive circuit default to be turned on and send a discharge drive signal to the discharge execution circuit, realizing the functions of safety isolation and low voltage locking. Thus, the discharge execution circuit discharges the voltage of the high voltage port to a safe range, avoiding the risk of discharge failure caused by abnormal low voltage power supply, and ensuring that the voltage of the high voltage port can be reliably discharged to a safe range (within the safety threshold) in various situations, guaranteeing the fast, reliable and safe discharge of the energy of the DC high voltage port.

[0039] In one embodiment, please refer to Figure 3 As shown, the above control module 12 includes a control switch tube 123, a first matching resistor-capacitor 121, and a first resistor 122.

[0040] The control signal input terminal is connected to the first end of the first matching resistor-capacitor 121 through the first resistor 122. The second end of the first matching resistor-capacitor 121 is connected to the gate of the control switch tube 123. The drain of the control switch tube 123 is connected to the second end of the isolation optocoupler 11. The source of the control switch tube 123 and the third end of the first matching resistor-capacitor 121 are both connected to the first grounding terminal.

[0041] Specifically, the control signal input terminal can be DRV_1. The above first resistor is used to limit the current to protect the gate of the control switch tube Q1, and it is a current limiting resistor. The first matching resistor-capacitor includes a resistor and a capacitor connected in parallel with the resistor. The parallel capacitor in the first matching resistor-capacitor is used to filter out high-frequency interference and stabilize the control signal. The control signal input terminal DRV_1 is connected to the gate of the control switch tube Q1 through the first resistor, receives the control instruction sent by the controller, and limits the current to protect the gate through the first resistor.

[0042] The control switch Q1 is used to control the on / off of the isolation optocoupler according to the signal of the control signal input terminal DRV_1. The control switch Q1 is controlled by the signal of the control signal input terminal DRV_1. When the control signal input terminal DRV_1 is at a high level, the gate voltage of the control switch Q1 is higher than the threshold value, so that the control switch Q1 is in the on state; when the control signal input terminal DRV_1 is at a low level, the gate voltage of the control switch Q1 is not higher than the threshold value, so that the control switch Q1 is in the off state.

[0043] Please continue to refer to Figure 3 As shown, the above isolation optocoupler 11 includes: a light-emitting diode 111 and an isolation switch tube 112.

[0044] The control signal input terminal is connected to the anode of the light-emitting diode 111 through the second resistor 113. The cathode of the light-emitting diode 111 is respectively connected to the drain of the control switch tube 123 and the gate of the isolation switch tube 112. The source and drain of the isolation switch tube 112 are connected to the secondary side drive circuit 20.

[0045] It should be noted that when the above light-emitting diode is irradiated by light, its reverse resistance will change, thereby generating a corresponding electrical signal to achieve optoelectronic conversion. The isolation switch tube is used to receive the signal of the light-emitting diode and convert it into an electrical signal and output it to the secondary side drive circuit.

[0046] In the normal control mode, when the control signal input terminal DRV_1 is at a high level, the control switch Q1 is turned on, the light-emitting diode in the isolation optocoupler is turned on, driving the isolation switch tube on the output side to be turned on, thereby activating the secondary side drive circuit. When the control signal input terminal DRV_1 is at a low level, the control switch Q1 is turned off, the light-emitting diode in the isolation optocoupler is turned off, driving the isolation switch tube on the output side to be turned off, so that the secondary side drive circuit stops discharging.

[0047] In the abnormal power-off mode, when the control signal input terminal is at a low level, the control switch Q1 is turned off, the light-emitting diode in the isolation optocoupler is turned off, driving the isolation switch tube on the output side to be turned off, and outputting a cut-off control signal to the secondary side drive circuit. However, since the drive power supply terminal in the secondary side drive circuit is powered on, it is defaulted to the discharging state, and the high-voltage port voltage is discharged to a safe range.

[0048] In this embodiment, by setting the light-emitting diode and the isolation switch tube to cooperate, a safe and reliable signal bridge is established between the high-voltage and low-voltage systems by the isolation optocoupler, avoiding the risk of high voltage penetrating into the low-voltage area.

[0049] In one of the embodiments, please continue to refer to Figure 3As shown, the above-mentioned secondary-side drive circuit includes: The secondary-side drive circuit 20 includes: a third resistor 21, a fourth resistor 22, a fifth resistor 23, a sixth resistor 24, a second matching resistor-capacitor 25, a third matching resistor-capacitor 26, a drive diode 27, and a bridge arm control circuit 28.

[0050] The drive power supply terminal is connected to one end of the third resistor 21, one end of the fourth resistor 22, and the cathode of the drive diode 27. The other end of the third resistor 21 is respectively connected to the drain of the isolation switch tube 112 and the second matching resistor-capacitor 25. The other end of the fourth resistor 22 is connected to the bridge arm control circuit 28. The bridge arm control circuit 28 is also connected to the second matching resistor-capacitor 25 and the third matching resistor-capacitor 26. One end of the fifth resistor 23 is connected to the source of the isolation switch tube 112. The anode of the drive diode 27 is connected to the bridge arm control circuit 28 and the third matching resistor-capacitor 26 through the sixth resistor 24. The other end of the fifth resistor 23, the second matching resistor-capacitor 25, and the third matching resistor-capacitor 26 are all connected to the second grounding terminal.

[0051] It should be noted that both the second matching resistor-capacitor and the third matching resistor-capacitor are capacitors and resistors connected in parallel with each other. The bridge arm control circuit may include a push-pull control bridge arm, and through this push-pull control bridge arm, a low-voltage lockout function is realized. The push-pull control bridge arm is a circuit structure composed of two switching devices connected in anti-parallel, and signal amplification or power drive is realized through alternate conduction and cut-off.

[0052] The above-mentioned fourth resistor is used to suppress the high-frequency oscillation of the upper transistor in the bridge arm control circuit (RC damping effect), and avoid mis-triggering of the gate voltage due to parasitic inductance and capacitance oscillation. The above-mentioned drive diode is used to prevent reverse current, ensure the unidirectional flow of the discharge current, and protect circuit components.

[0053] The above-mentioned bridge arm control circuit has signal amplification and bidirectional drive functions. Through the complementary conduction of two switching devices, the small signal of the isolation optocoupler is amplified into a sufficient gate drive current (or voltage) to ensure that the discharge switch conducts / turns off quickly and reliably.

[0054] When discharge processing is required, the upper transistor of the push-pull bridge arm conducts and the lower transistor cuts off, providing a positive drive voltage (such as +12V) for the discharge execution circuit to make it perform discharge processing. When the discharge is completed, the lower transistor of the push-pull bridge arm conducts and the upper transistor cuts off, quickly pulling down the discharge execution circuit to the ground (or negative voltage) to accelerate its turn-off and avoid mis-conduction caused by residual gate charge.

[0055] Among them, please refer to Figure 4 As shown, the above-mentioned bridge arm control circuit 28 includes a first bridge arm Q2 and a second bridge arm Q3.

[0056] The drain of the first bridge arm Q2 is connected to the other end of the fourth resistor 22. The gate of the first bridge arm Q2 is respectively connected to the second matching resistor-capacitor 25 and the gate of the second bridge arm Q3. The source of the first bridge arm Q2 is connected to the drain of the second bridge arm Q3. The source of the second bridge arm Q3 is respectively connected to the second matching resistor-capacitor 25 and the third matching resistor-capacitor 26. The drain of the second bridge arm Q3 is further connected to the other end of the sixth resistor 24 and the third matching resistor-capacitor 26.

[0057] It can be understood that the first bridge arm Q2 and the second bridge arm Q3 can be push-pull control bridge arms, both of which are field effect transistors, playing a role in signal amplification and driving, driving the discharge circuit switch Q4, and realizing the low-voltage lock function. After the control signal transmitted by the isolation optocoupler is processed by the first bridge arm Q2 and the second bridge arm Q3 in the push-pull control bridge arm, the discharge circuit switch Q4 in the discharge execution circuit can be driven more effectively.

[0058] Specifically, in the normal control mode, when the control power supply terminal is powered on and the drive power supply terminal is powered on, when the control signal input terminal is at a high level, the drive isolation optocoupler is turned on, and then a conduction control signal is generated and sent to the secondary drive circuit, making the first bridge arm Q2 in the secondary drive circuit cut off and the second bridge arm Q3 conduct, then a discharge drive signal is generated to the discharge execution circuit, making the discharge process be executed. When the control signal input terminal is at a low level, the drive isolation optocoupler is turned off, and then a cut-off control signal is generated and sent to the secondary drive circuit, making the first bridge arm Q2 in the secondary drive circuit conduct and the second bridge arm Q3 cut off, then the discharge stops.

[0059] In the abnormal power-off mode, when the control power supply terminal is powered off and the drive power supply terminal is powered on, the isolation optocoupler loses its drive, and then a cut-off control signal is generated and sent to the secondary drive circuit. Since the drive power supply terminal in the secondary drive circuit is powered on, the first bridge arm Q2 in the secondary drive circuit is cut off and the second bridge arm Q3 conducts, then the voltage of the high-voltage port continues to be discharged until the voltage is discharged to a safe range.

[0060] In this embodiment, the bridge arm control circuit includes a first bridge arm and a second bridge arm. By complementary conduction and cut-off, it prevents the short circuit of the end elements, synchronously utilizes the "synchronous rectification" characteristic (when the lower bridge arm conducts, the parasitic diode of the upper bridge arm is reversely cut off), reduces energy loss, and realizes voltage inversion, power amplification or energy bidirectional transmission. Even when the primary control signal is cut off, the secondary drive circuit can still independently complete the discharge task and avoid the risk of high-voltage residue.

[0061] In one of the embodiments, please continue to refer to Figure 4 As shown, the above-mentioned discharge execution circuit includes: a discharge circuit switch and a first discharge resistor R1, a second discharge resistor R2, a third discharge resistor R3, and a fourth discharge resistor R4 connected in series in sequence.

[0062] The third matching resistor-capacitor is connected to the gate of the discharge circuit switch Q4, the first discharge resistor R1 is connected to the high-voltage port, the fourth discharge resistor R4 is connected to the drain of the discharge circuit switch Q4, and the source of the discharge circuit switch Q4 is connected to the second ground terminal.

[0063] It should be noted that the above-mentioned first discharge resistor, second discharge resistor, third discharge resistor, and fourth discharge resistor can adopt high-voltage-resistant and high-power resistors to ensure that the high-voltage energy can be safely consumed. Among them, the discharge circuit switch can select a MOSFET with a voltage higher than the voltage value of the high-voltage port. Usually, the withstand voltage value should be at least 1.5 times the voltage of the high-voltage port or more to ensure safety. At the same time, this MOSFET needs to have a low on-resistance to reduce power loss in the on state.

[0064] Exemplarily, please refer to Figure 5 As shown, taking the control power supply terminal as VCC_1, the drive power supply terminal as VCC_2, the control signal input terminal as DRV_1, the first ground terminal as GND_1, and the second ground terminal as GND_2 as an example. In the normal control mode, after VCC_1 is powered on, the circuit is in a controllable state. At this time, the discharge circuit can be controlled to be disconnected before startup. When the circuit receives a shutdown instruction or abnormal power-off (the bus is powered), the controller receives a discharge instruction and checks whether the high-voltage port voltage is greater than or equal to 60V. When the high-voltage port voltage ≥ 60V, a high-level signal is given at the control signal input terminal, making the control switch tube Q1 conduct, and driving the isolation optocoupler 11 to conduct. Then, a conduction control signal is output to the secondary drive circuit, making the first arm Q2 in the secondary drive circuit cut off and the second arm Q3 conduct, generating a discharge drive signal and sending it to the discharge execution circuit. The discharge circuit switch Q4 conducts, and the high-voltage port voltage is discharged through the first discharge resistor R1, the second discharge resistor R2, the third discharge resistor R3, and the fourth discharge resistor R4.

[0065] When the high-voltage port voltage < 60V, a low-level signal is given at the control signal input terminal, making the control switch tube Q1 cut off, and driving the isolation optocoupler 11 to cut off. Then, a cut-off control signal is output to the secondary drive circuit, making the first arm Q2 in the secondary drive circuit conduct and the second arm Q3 cut off, and further driving the discharge circuit switch Q4 in the discharge execution circuit to cut off, stopping the discharge process.

[0066] In the abnormal power-off mode, VCC_1 loses power, that is, a low-level signal is given at the control signal input terminal, causing the control switch Q1 to turn off and driving the isolation optocoupler 11 to turn off. Then, a cut-off control signal is output to the secondary side drive circuit. However, at this time, the high-voltage bus has not been discharged completely. Since VCC_2 is powered on, the secondary side drive circuit is in the default low-voltage lock state, causing the first bridge arm Q2 in the secondary side drive circuit to turn off and the second bridge arm Q3 to turn on, generating a discharge drive signal to the discharge execution circuit. The discharge circuit switch Q4 is forced to turn on, and the high-voltage port voltage is continuously discharged through the first discharge resistor R1, the second discharge resistor R2, the third discharge resistor R3, and the fourth discharge resistor R4 until the high-voltage port voltage is within the safe range (voltage < 60V).

[0067] In this embodiment, by setting a high-voltage discharge circuit with a low-voltage lock function, the purpose of discharging the high-voltage energy of the DC port is achieved. It can not only make the isolation between the primary and secondary sides safer, but also ensure that the port voltage energy is discharged stably and reliably, the port voltage drops rapidly, and the primary side control power-off does not affect the discharge, meeting the discharge design requirement of the port voltage < 60V.

[0068] On the other hand, an embodiment of the present application provides a power supply system, which includes the high-voltage discharge circuit provided in the above embodiment.

[0069] Specifically, other chips may also be included in the above power supply system. The other chips may be processor chips, sensor chips, storage chips, communication chips, or control chips, which are used to implement functions such as calculation, storage, communication, sensing, and control.

[0070] The power supply system provided in this embodiment includes the above high-voltage discharge circuit. Since an isolation optocoupler is provided in the primary side control circuit, electrical isolation between the primary side control circuit and the secondary side drive circuit can be achieved, avoiding the risk of high voltage penetrating into the low-voltage area. At the same time, while one end of the secondary side drive circuit is connected to the primary side control circuit and the other end is connected to the discharge execution circuit, a drive power supply terminal is set to independently supply power to the secondary side drive circuit. When the primary side control circuit meets the power-off enable condition and the drive power supply terminal is powered on, after the secondary side drive circuit detects that the isolation optocoupler is turned off, since the drive power supply terminal still has power, the secondary side drive circuit can be default-conducted and send a discharge drive signal to the discharge execution circuit, realizing the functions of safety isolation and low-voltage lock. As a result, the discharge execution circuit discharges the voltage of the high-voltage port to the safe range, avoiding the risk of discharge failure caused by abnormal low-voltage power supply, ensuring that the high-voltage port voltage is reliably discharged to the safe range (within the safety threshold) in various situations, and guaranteeing the fast, reliable, and safe discharge of the DC high-voltage port energy.

[0071] On the other hand, an embodiment of the present application also provides a control method. It is applied to the high-voltage discharge circuit provided in the above embodiment.Figure 6 The figure shows a schematic flowchart of the control method according to an embodiment of the present application. As Figure 6 shown, the method includes: S101. In the abnormal power-off mode, the primary control circuit outputs a cut-off control signal to the secondary drive circuit through an isolation optocoupler; the abnormal power-off mode includes: the primary control circuit satisfies the power-off enable condition and the drive power supply terminal is powered on, and the power-off enable condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level.

[0072] S102. The secondary drive circuit amplifies the control signal and then generates a discharge drive signal and sends it to the discharge execution circuit.

[0073] S103. The discharge execution circuit discharges the voltage of the high-voltage port to a safe range according to the discharge drive signal.

[0074] The above high-voltage discharge circuit includes a primary control circuit, a secondary drive circuit, and a discharge execution circuit. Different circuits perform different functions. When the device is powered on, regardless of the power-on sequence of the control power supply terminal and the drive power supply terminal, the circuit will start discharging after the drive power supply terminal is powered on.

[0075] Specifically, in the normal control mode, when the control power supply terminal is powered on, after the circuit receives a shutdown command or abnormal power-off (the bus is powered), the controller receives a discharge command and checks whether the voltage of the high-voltage port is greater than or equal to 60V. When the voltage of the high-voltage port ≥ 60V, a high-level signal is given at the control signal input terminal, so that the control switch Q1 is turned on, and the isolation optocoupler is driven to conduct, then a conduction control signal is output to the secondary drive circuit, so that the first bridge arm Q2 in the secondary drive circuit is turned off and the second bridge arm Q3 is turned on, generating a discharge drive signal to the discharge execution circuit, controlling the discharge circuit switch Q4 to conduct, and discharging the voltage of the high-voltage port through a plurality of discharge resistors.

[0076] When the voltage of the high-voltage port < 60V, a low-level signal is given at the control signal input terminal, so that the control switch Q1 is turned off, and the isolation optocoupler is driven to cut off, then a cut-off control signal is output to the secondary drive circuit, so that the first bridge arm Q2 in the secondary drive circuit is turned on and the second bridge arm Q3 is turned off, and then the discharge circuit switch Q4 in the discharge execution circuit is driven to cut off, stopping the discharge process.

[0077] In the abnormal power-off mode, the control power supply terminal is powered off, and a low-level signal is given at the control signal input terminal, causing the control switch transistor Q1 to turn off and driving the isolation optocoupler to turn off. Then, a cut-off control signal is output to the secondary side drive circuit. However, at this time, the high-voltage bus has not been discharged completely. Since the drive power supply terminal is powered on, the secondary side drive circuit defaults to the low-voltage lock state, causing the first bridge arm Q2 in the secondary side drive circuit to turn off and the second bridge arm Q3 to turn on, generating a discharge drive signal to the discharge execution circuit. The discharge circuit switch Q4 is forced to turn on, and the high-voltage port voltage is continuously discharged through multiple discharge resistors until the high-voltage port voltage is within the safe range (voltage < 60V).

[0078] In the control method provided by the embodiment of the present application, since an isolation optocoupler is provided in the primary side control circuit, electrical isolation between the primary side control circuit and the secondary side drive circuit can be achieved, avoiding the risk of high voltage penetrating into the low-voltage area. At the same time, while one end of the secondary side drive circuit is connected to the primary side control circuit and the other end is connected to the discharge execution circuit, a drive power supply terminal is set to independently supply power to the secondary side drive circuit. When the primary side control circuit meets the power-off enable condition and the drive power supply terminal is powered on, after the secondary side drive circuit detects that the isolation optocoupler is turned off, since the drive power supply terminal still has power, it can cause the secondary side drive circuit to default to conduction and send a discharge drive signal to the discharge execution circuit, realizing the functions of safety isolation and low-voltage locking. Thus, the discharge execution circuit discharges the voltage of the high-voltage port to the safe range, avoiding the risk of discharge failure caused by abnormal low-voltage power supply, ensuring that the high-voltage port voltage can be reliably discharged to the safe range (within the safety threshold) under various conditions, and guaranteeing the fast, reliable and safe discharge of the energy of the DC high-voltage port.

[0079] It should be noted that although the operations of the method of the present invention are described in a specific order in the drawings, this does not require or imply that these operations must be performed in that specific order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flowchart can be changed in the order of execution. Additionally or alternatively, some steps may be omitted, multiple steps may be combined into one step for execution, and / or one step may be decomposed into multiple steps for execution.

[0080] In summary, the high-voltage discharge circuit, power supply system and control method provided by the embodiments of the present application. The high-voltage discharge circuit includes a primary control circuit, a secondary drive circuit, and a discharge execution circuit. The primary control circuit includes an isolation optocoupler and a control module. The first end of the isolation optocoupler is connected to the control power supply terminal, the second end of the isolation optocoupler is connected to one end of the control module, the other end of the control module is respectively connected to the control signal input terminal and the first ground terminal, the third end of the isolation optocoupler is connected to the secondary drive circuit, the secondary drive circuit is also connected to the drive power supply terminal, the second ground terminal, and the discharge execution circuit, and the discharge execution circuit is also connected to the high-voltage port and the second ground terminal; the high-voltage port is used to receive a voltage value greater than a preset threshold. The primary control circuit is used for: in the abnormal power-off mode, outputting a cut-off control signal to the secondary drive circuit through the isolation optocoupler; the abnormal power-off mode includes: the primary control circuit satisfies the power-off enable condition and the drive power supply terminal is powered on, and the power-off enable condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level; the secondary drive circuit is used for: generating a discharge drive signal according to the cut-off control signal and sending it to the discharge execution circuit; the discharge execution circuit is used for: according to the discharge drive signal, discharging the voltage of the high-voltage port to a safe range. Compared with the prior art, since the isolation optocoupler is provided in the primary control circuit of the high-voltage discharge circuit provided by the present application, electrical isolation between the primary control circuit and the secondary drive circuit can be achieved, avoiding the risk of high voltage penetrating into the low-voltage area. At the same time, while one end of the secondary drive circuit is connected to the primary control circuit and the other end is connected to the discharge execution circuit, a drive power supply terminal is set to independently supply power to the secondary drive circuit. When the primary control circuit satisfies the power-off enable condition and the drive power supply terminal is powered on, after the secondary drive circuit detects that the isolation optocoupler is cut off, since the drive power supply terminal still has power, the secondary drive circuit can be default-conducted and send a discharge drive signal to the discharge execution circuit, realizing the functions of safety isolation and low-voltage locking. As a result, the discharge execution circuit discharges the voltage of the high-voltage port to a safe range, avoiding the risk of discharge failure caused by abnormal low-voltage power supply, ensuring that the voltage of the high-voltage port can be reliably discharged to a safe range (within the safety threshold) in various situations, and guaranteeing the fast, reliable and safe discharge of the energy of the DC high-voltage port.

[0081] The above description is only a preferred embodiment of the present application and an explanation of the applied technical principles. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by the specific combination of the above technical features, and should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the technical solutions formed by mutually replacing the above features with the (but not limited to) technical features with similar functions disclosed in the present application.

Claims

1. A high-voltage discharge circuit, characterized in that, The high-voltage discharge circuit includes: a primary control circuit, a secondary drive circuit, and a discharge execution circuit. The primary control circuit includes an isolation optocoupler and a control module. The first end of the isolation optocoupler is connected to the control power supply terminal. The second end of the isolation optocoupler is connected to one end of the control module. The other end of the control module is respectively connected to the control signal input terminal and the first ground terminal. The third end of the isolation optocoupler is connected to the secondary drive circuit. The secondary drive circuit is also connected to the drive power supply terminal, the second ground terminal, and the discharge execution circuit. The discharge execution circuit is also connected to the high-voltage port and the second ground terminal. The high-voltage port is used to receive a voltage value greater than a preset threshold value. The primary control circuit is used for: in the abnormal power-off mode, outputting a cut-off control signal to the secondary drive circuit through the isolation optocoupler. The abnormal power-off mode includes: the primary control circuit meets the power-off enable condition and the drive power supply terminal is powered on. The power-off enable condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level. The secondary drive circuit is used for: generating a discharge drive signal according to the cut-off control signal and sending it to the discharge execution circuit. The discharge execution circuit is used for: discharging the voltage of the high-voltage port to a safe range according to the discharge drive signal.

2. The high-voltage discharge circuit according to claim 1, wherein The control module includes: a control switch tube, a first matching resistor-capacitor, and a first resistor. The control signal input terminal is connected to the first end of the first matching resistor-capacitor through the first resistor. The second end of the first matching resistor-capacitor is connected to the gate of the control switch tube. The drain of the control switch tube is connected to the second end of the isolation optocoupler. The source of the control switch tube and the third end of the first matching resistor-capacitor are both connected to the first ground terminal.

3. The high-voltage discharge circuit according to claim 2, wherein The isolation optocoupler includes: a light-emitting diode and an isolation switch tube. The control signal input terminal is connected to the anode of the light-emitting diode through a second resistor. The cathode of the light-emitting diode is respectively connected to the drain of the control switch tube and the gate of the isolation switch tube. The source and drain of the isolation switch tube are connected to the secondary drive circuit.

4. The high-voltage discharge circuit according to claim 3, wherein, The secondary drive circuit includes: a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a second matching resistor-capacitor, a third matching resistor-capacitor, a drive diode, and a bridge control circuit. The drive power supply terminal is connected to one end of the third resistor, one end of the fourth resistor, and the cathode of the drive diode. The other end of the third resistor is respectively connected to the drain of the isolation switch tube and the second matching resistor-capacitor. The other end of the fourth resistor is connected to the bridge control circuit. The bridge control circuit is also connected to the second matching resistor-capacitor and the third matching resistor-capacitor. One end of the fifth resistor is connected to the source of the isolation switch tube. The anode of the drive diode is connected to the bridge control circuit and the third matching resistor-capacitor through the sixth resistor. The other end of the fifth resistor, the second matching resistor-capacitor, and the third matching resistor-capacitor are all connected to the second ground terminal.

5. The high-voltage discharge circuit according to claim 4, characterized in that The bridge control circuit includes a first bridge arm and a second bridge arm. The drain of the first bridge arm is connected to the other end of the fourth resistor. The gate of the first bridge arm is respectively connected to the second matching resistor-capacitor and the gate of the second bridge arm. The source of the first bridge arm is connected to the drain of the second bridge arm. The source of the second bridge arm is respectively connected to the second matching resistor-capacitor and the third matching resistor-capacitor. The drain of the second bridge arm is also connected to the other end of the sixth resistor and the third matching resistor-capacitor.

6. The high-voltage discharge circuit according to claim 4, characterized in that, The discharge execution circuit includes: a discharge circuit switch and a first discharge resistor, a second discharge resistor, a third discharge resistor, and a fourth discharge resistor connected in series in sequence; The third matching resistor-capacitor is connected to the gate of the discharge circuit switch. The first discharge resistor is connected to the high-voltage port. The fourth discharge resistor is connected to the drain of the discharge circuit switch. The source of the discharge circuit switch is connected to the second grounding end.

7. The high-voltage discharge circuit according to claim 4, characterized in that The first matching resistor-capacitor, the second matching resistor-capacitor, and the third matching resistor-capacitor each include a capacitor and a resistor connected in parallel with each other.

8. The high-voltage discharge circuit according to claim 1, characterized in that The primary control circuit is further configured to: In the normal control mode, when the control signal input terminal is at a high level, output a conduction control signal to the secondary drive circuit through the isolation optocoupler, so that the secondary drive circuit drives the discharge execution circuit to discharge the voltage of the high-voltage port to a safe range; The normal control mode includes: the control power supply terminal is powered on and the drive power supply terminal is powered on; When the control signal input terminal is at a low level, output a cut-off control signal to the secondary drive circuit through the isolation optocoupler, so that the secondary drive circuit stops discharging the discharge execution circuit.

9. A power supply system, characterized in that, The power supply system includes the high-voltage discharge circuit according to any one of the above claims 1-8.

10. A control method, characterized in that, Applied to the high-voltage discharge circuit according to any one of claims 1-8, the control method includes: In the abnormal power-off mode, the primary control circuit outputs a cut-off control signal to the secondary drive circuit through the isolation optocoupler; the abnormal power-off mode includes: the primary control circuit satisfies the power-off enable condition and the drive power supply terminal is powered on, and the power-off enable condition includes: the control power supply terminal is powered off or the control signal input terminal is at a low level; The secondary drive circuit amplifies the control signal and generates a discharge drive signal and sends it to the discharge execution circuit; The discharge execution circuit discharges the voltage of the high-voltage port to a safe range according to the discharge drive signal.

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