Vehicle traction control circuit, discharge control method, inverter and high-voltage box

Abstract

The present application relates to the technical field of vehicle traction control, and discloses a vehicle traction control circuit, a discharge control method, an inverter and a high-voltage box. The bus is used to receive an electrical signal from an external power source, and the electrical signal from the bus is converted and output through an inverter circuit connected to the bus to pull the vehicle. The inverter circuit includes a capacitor, a first resistor and a switch component, and the capacitor is connected in series with the bus; the first resistor and the switch component are connected in series and connected in parallel with the capacitor, and the first resistor is used to discharge when the voltage in the inverter circuit is greater than a preset threshold. When the capacitor needs to be discharged, the switch component is closed, and the discharge circuit formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor. The existing first resistor in the circuit is used for active discharge, and there is no need to set an additional resistor, thereby reducing costs.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle traction control, and in particular to a vehicle traction control circuit, a discharge control method, an inverter and a high-voltage box. Background Art

[0002] With the development of electrification and the continuous improvement of rail vehicle performance, the stable operation of rail transit traction systems has become increasingly important. In some cases, it is necessary to discharge the residual voltage in the traction system.

[0003] In the related art, the motor controller controls the connection of the three-phase circuit of the motor, and the motor completes the rapid discharge of charge to ensure the stable operation of the system. However, the related art will cause the motor and the motor controller to heat up, and if the control fails, abnormal conditions may occur. In other related arts, discharge is carried out by setting up many additional components or complex circuit structures. The introduction of additional components leads to high costs, and the complex circuit structure is prone to failure. Therefore, it is necessary to propose a safer and lower-cost vehicle traction control circuit. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to a certain extent. To this end, the present application proposes a traction control circuit, a discharge control method, an inverter and a high-voltage box for a vehicle.

[0005] The present application provides a traction control circuit for a vehicle, the traction control circuit comprising: a busbar, for receiving an electrical signal from an external power supply; an inverter circuit, connected to the busbar, the inverter circuit being used to convert and output the electrical signal from the busbar to tow the vehicle; wherein the inverter circuit comprises a capacitor, a first resistor and a switch component; the capacitor is connected in series with the busbar; the first resistor is connected in series with the switch component and connected in parallel with the capacitor, the first resistor being used to discharge when the voltage in the inverter circuit is greater than a preset threshold; wherein, when the capacitor needs to be discharged, the switch component is closed, and a discharge loop formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor.

[0006] Optionally, the switch component includes at least one of a first type switch and a second type switch; after the first type switch is closed, a first discharge loop formed by the capacitor, the first resistor and the first type switch is turned on; after the second type switch is turned on, a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on, wherein, when the switch component includes both the first type switch and the second type switch, the first type switch and the second type switch are connected in parallel and connected in series with the first resistor.

[0007] Optionally, the inverter circuit includes a first bridge arm, the first bridge arm includes an upper bridge arm and a lower bridge arm connected to the upper bridge arm, one end of the upper bridge arm is connected to the positive pole of the bus, and one end of the lower bridge arm is connected to the negative pole of the bus; the connection point between the upper bridge arm and the lower bridge arm is connected to one end of the first resistor, and the other end of the first resistor is connected to the negative pole of the bus; the upper bridge arm includes an insulated gate bipolar transistor IGBT, the insulated gate bipolar transistor IGBT serves as the second type switch, and the lower bridge arm includes a diode, the cathode of the diode is connected to the upper bridge arm, and the anode of the diode is connected to the negative pole of the bus.

[0008] Optionally, the traction control circuit also includes a control circuit; the control circuit includes at least one of the following: an isolating switch, which is connected in series with the bus and forms an interlock with the first type switch, and when the isolating switch is disconnected, the first type switch is triggered to close, so that the first discharge circuit formed by the capacitor, the first resistor and the first type switch is turned on to discharge the voltage of the capacitor through the first resistor; a traction control unit, which is connected to the second type switch, and the traction control unit is used to control the second type switch to be turned on, so that the second discharge circuit formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0009] Optionally, the traction control circuit also includes: a voltage sensor for detecting the voltage of the capacitor; wherein the traction control unit is also used to determine whether the voltage of the capacitor detected by the voltage sensor is lower than the safety voltage after the isolation switch is disconnected for a preset time period. If not, the traction control unit controls the second type switch to be turned on, so that the second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0010] Optionally, the inverter circuit is at least a partial circuit in an inverter; the traction control unit is also used to: when detecting an opening signal of the inverter, determine whether the voltage of the capacitor detected by the voltage sensor is lower than a safety voltage; if not, control the second type switch to be turned on, so that the second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0011] Optionally, the traction control unit is also used to: when receiving a leakage signal from the traction control circuit, control the second type switch to be turned on, so that the second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor until it is determined that the voltage of the capacitor detected by the voltage sensor is lower than the safety voltage.

[0012] Optionally, the inverter circuit also includes: a second resistor, connected in parallel with the capacitor, wherein the resistance of the second resistor is greater than the resistance of the first resistor; when the capacitor needs to be discharged, a third discharge loop formed by the second resistor and the capacitor is turned on to discharge the voltage of the capacitor through the second resistor.

[0013] Optionally, the traction control circuit also includes: a charging circuit, connected in series with the bus, for charging the capacitor before the vehicle runs; wherein the charging circuit includes a first contactor, a second contactor and a third resistor; the first contactor is connected in series with the bus; the second contactor is connected in series with the third resistor and connected in parallel with the first contactor; wherein, when the capacitor is charged through the charging circuit, the first contactor is disconnected and the second contactor is closed.

[0014] According to the traction control circuit of the vehicle of the embodiment of the present application, the traction control circuit includes at least two of the inverter circuits, and the at least two inverter circuits include a first inverter circuit and a second inverter circuit; when it is necessary to discharge the capacitor in the first inverter circuit, the discharge circuit formed by the capacitor in the first inverter circuit, the first resistor in the second inverter circuit, and the switch component in the second inverter circuit is turned on to discharge the voltage of the capacitor in the first inverter circuit through the first resistor in the second inverter circuit; when it is necessary to discharge the capacitor in the second inverter circuit, at least the switch component in the first inverter circuit is controlled to be closed, so that the discharge circuit formed by the capacitor in the second inverter circuit, the first resistor in the first inverter circuit, and the switch component in the first inverter circuit is turned on to discharge the voltage of the capacitor in the second inverter circuit through the first resistor in the first inverter circuit.

[0015] The present application also proposes a discharge control method for a vehicle traction system, the discharge control method comprising: detecting a discharge demand signal of a capacitor in the traction control circuit; when it is determined based on the discharge demand signal that the capacitor needs to be discharged, controlling the switch component to close so that a discharge loop formed by the capacitor, the first resistor and the switch component is turned on, so as to discharge the voltage of the capacitor through the first resistor.

[0016] Optionally, the discharge demand signal includes a signal indicating whether the isolating switch connected in series with the bus is disconnected, and the switch component includes a first type switch, and the isolating switch is linked with the first type switch; when it is determined based on the discharge demand signal that the capacitor needs to be discharged, controlling the switch component to close includes: when the discharge demand signal indicates that the isolating switch is disconnected, triggering the first type switch to close, so that a first discharge loop formed by the capacitor, the first resistor and the first type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor.

[0017] Optionally, the switch component includes a second type switch, and the discharge requirement signal includes a signal indicating whether the traction control unit generates a signal for controlling the second type switch to be turned on; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to be closed includes: when the discharge requirement signal indicates that the traction control unit generates a signal for controlling the second type switch to be turned on, controlling the second type switch to be turned on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0018] Optionally, the switch component includes a first type switch and a second type switch; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close includes: when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, the isolating switch connected in series with the bus is disconnected and the first type switch is triggered to close, so that a first discharge loop formed by the capacitor, the first resistor and the first type switch is turned on to discharge the voltage of the capacitor through the first resistor; after the isolating switch is turned off for a preset time period, determining whether the voltage of the capacitor is lower than a safety voltage; if not, controlling the second type switch to turn on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0019] Optionally, the switch component includes a second type switch, the inverter circuit is at least a partial circuit in an inverter, and the discharge demand signal includes a signal indicating whether the inverter is open; when it is determined based on the discharge demand signal that the capacitor needs to be discharged, controlling the switch component to close includes: when it is determined based on the discharge demand signal that the inverter is open, determining whether the voltage of the capacitor is lower than a safety voltage; if not, controlling the second type switch to be turned on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0020] Optionally, the switch component includes a second type switch, and the discharge requirement signal includes a signal indicating whether the traction control circuit is leaking; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, the switch component is controlled to close, including: when it is determined based on the discharge requirement signal that the traction control circuit is leaking, determining whether the voltage of the capacitor is lower than a safety voltage; if not, controlling the second type switch to be turned on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

[0021] Optionally, the inverter circuit also includes a second resistor connected in parallel with the capacitor, the resistance of the second resistor is greater than the resistance of the first resistor, and the discharge requirement signal includes an indication of whether the traction control circuit has stopped being powered by an external power supply; the discharge control method also includes: when it is determined based on the discharge requirement signal that the traction control circuit has stopped being powered by an external power supply, a third discharge loop formed by the second resistor and the capacitor is turned on, and the voltage of the capacitor is discharged through the second resistor.

[0022] Optionally, the traction control circuit includes at least two of the inverter circuits, and the at least two inverter circuits include a first inverter circuit and a second inverter circuit; when it is determined based on the discharge requirement signal that the capacitor in the first inverter circuit needs to be discharged, controlling the switch component to close includes: when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, at least controlling the switch component in the second inverter circuit to close, so that the discharge loop formed by the capacitor in the first inverter circuit, the first resistor in the second inverter circuit and the switch component in the second inverter circuit is turned on, so as to discharge the voltage of the capacitor in the first inverter circuit through the first resistor in the second inverter circuit; when it is determined based on the discharge requirement signal that the capacitor in the second inverter circuit needs to be discharged, at least controlling the switch component in the first inverter circuit to close, so that the discharge loop formed by the capacitor in the second inverter circuit, the first resistor in the first inverter circuit and the switch component in the first inverter circuit is turned on, so as to discharge the voltage of the capacitor in the second inverter circuit through the first resistor in the first inverter circuit.

[0023] The present application also proposes an inverter, which includes an inverter circuit, which is connected to a bus, and is used to convert and output an electrical signal from the bus to tow a vehicle; the inverter circuit includes a capacitor, a first resistor and a switch component, and the capacitor is connected in series with the bus; the first resistor and the switch component are connected in series and in parallel with the capacitor, and the first resistor is used to discharge when the voltage in the inverter circuit is greater than a preset threshold; when the capacitor needs to be discharged, the switch component is closed, and the discharge loop formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor.

[0024] The present application also proposes a high-voltage box, which includes the traction control circuit described in any one of the above embodiments.

[0025] The present application also proposes a vehicle, the vehicle comprising any one of the traction control circuits described above, or the vehicle being used to implement the steps of any one of the discharge control methods described above, or the vehicle comprising the inverter described above, or the vehicle comprising the high-voltage box described above.

[0026] The present application also proposes an electronic device, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the computer program, the steps of the method described in any one of the above embodiments are implemented.

[0027] The present application also proposes a computer-readable storage medium having a computer program stored thereon, and when the computer program is executed by a processor, the steps of the method described in any one of the above embodiments are implemented.

[0028] The present application also proposes a computer program product, which includes instructions. When the instructions are executed by a processor of a computer device, the computer device can execute the steps of the method described in any one of the above embodiments.

[0029] In the traction control circuit of the above-mentioned vehicle, the busbar is used to receive the electrical signal of the external power supply, and the electrical signal from the busbar is converted and output through the inverter circuit connected to the busbar to traction the vehicle. Among them, the inverter circuit includes a capacitor, a first resistor and a switch component, the capacitor is connected in series with the busbar; the first resistor is connected in series with the switch component and connected in parallel with the capacitor, and the first resistor is used to discharge when the voltage in the inverter circuit is greater than a preset threshold. When the capacitor needs to be discharged, the switch component is closed, and the discharge circuit formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor. By modifying the control logic, the original first resistor in the traction control circuit is used as a component for discharging the capacitor, and there is no need to set up an additional resistor for discharging the capacitor, which reduces the cost, and there is no need to add too many additional resistors to discharge the capacitor. Instead, the circuit logic is modified based on the first resistor, making the circuit control logic simple and error-prone. In addition, since the first resistor is originally used to discharge when the voltage in the inverter circuit is greater than a preset threshold, the resistance capacity of the first resistor is usually large. Using the first resistor to discharge the voltage of the capacitor can increase the discharge speed and achieve a better discharge effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A circuit schematic diagram of a traction control circuit of a vehicle provided in an embodiment of this specification;

[0031] Figure 2 A circuit schematic diagram of a traction control circuit of a vehicle including two inverter circuits provided in an embodiment of this specification;

[0032] Figure 3 A flow chart of a discharge control method for a vehicle traction system provided in an embodiment of this specification;

[0033] Figure 4 A schematic diagram of a flow chart of discharging the voltage of a capacitor through a first resistor when the isolating switch provided in an embodiment of this specification is disconnected;

[0034] Figure 5A schematic diagram of a flow chart of discharging the voltage of a capacitor through a first resistor when the inverter is open provided in an embodiment of this specification;

[0035] Figure 6 A schematic diagram of a flow chart of discharging the voltage of a capacitor through a first resistor when a traction control circuit is leaking provided in an embodiment of this specification;

[0036] Figure 7 A flow chart of a vehicle traction control method provided in an embodiment of this specification;

[0037] Figure 8 A schematic diagram of the internal structure of an electronic device provided in an embodiment of this specification. DETAILED DESCRIPTION

[0038] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0039] With the development of electrification and the continuous improvement of rail train performance, in order to ensure the stable operation of rail transit traction systems, large-capacity DC bus capacitors are usually used in the main circuit. Before the vehicle starts, the DC bus capacitor is charged through the pre-charging circuit, and the train starts running after the capacitor is fully charged to avoid undervoltage or overvoltage in the inverter due to abnormal conditions such as grid voltage fluctuations during train operation. However, when the train needs to stop for maintenance, in order to ensure the safety of maintenance personnel, it is necessary to quickly reduce the voltage of the bus capacitor to below the safe voltage, or when the vehicle has a leakage or other fault, it is necessary to quickly discharge the capacitor for leakage detection. Therefore, a fast discharge circuit is usually designed in the vehicle's traction control circuit, which can quickly reduce the voltage of the bus capacitor to below the safe voltage within a few seconds.

[0040] In the related art, a separate active discharge resistor and switch are used to realize the discharge function. However, the circuit integration in the related art is low, resulting in high cost. Secondly, due to the need to consider the heat dissipation problem, the circuit occupies a large space. In addition, due to the lack of effective safety measures, the safety is poor.

[0041] In the related art, the traction control circuit of the vehicle is formed by sharing the pre-charge resistor and the discharge resistor, which can save components and reduce the volume. However, due to the different requirements for charging and discharging, it is difficult for the resistor to meet the requirements of pre-charging and fast discharge capacity and heat generation at the same time, and the applicable scenarios are limited. In addition, the resistor is used more frequently for charging and discharging, and its life is short.

[0042] In the related art, the motor controller controls the connection of the motor's three-phase circuit, and the motor discharges the charge quickly. However, the related art will cause the motor and the motor controller to heat up, which will affect their service life. If the control fails, the motor may rotate and cause the vehicle to move abnormally.

[0043] In the related art, the common discharge and active discharge functions are realized by combining multiple resistors. However, the control circuit and the discharge circuit are relatively complex, and if a fault occurs, the active discharge function cannot be realized.

[0044] Based on the above analysis, the embodiment of this specification provides a traction control circuit for a vehicle. The busbar is used to receive the electrical signal of the external power supply, and the electrical signal from the busbar is converted and output through the inverter circuit connected to the busbar to traction the vehicle. Among them, the inverter circuit includes a capacitor, a first resistor and a switch component, the capacitor is connected in series with the busbar; the first resistor is connected in series with the switch component and connected in parallel with the capacitor, and the first resistor is used to discharge when the voltage in the inverter circuit is greater than a preset threshold. When the capacitor needs to be discharged, the switch component is closed, and the discharge circuit formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor. By modifying the control logic, the original first resistor in the traction control circuit is used as a component for discharging the capacitor, and there is no need to set up an additional resistor for discharging the capacitor, which reduces the cost, and there is no need to add too many additional resistors to discharge the capacitor. Instead, the circuit logic is modified based on the first resistor, so that the circuit control logic is simple and error-prone. In addition, since the first resistor is originally used to discharge when the voltage in the inverter circuit is greater than a preset threshold, the resistance capacity of the first resistor is usually large. Using the first resistor to discharge the voltage of the capacitor can increase the discharge speed and achieve a better discharge effect.

[0045] Figure 1 A circuit schematic diagram of a traction control circuit of a vehicle provided in an embodiment of this specification.

[0046] For example, see Figure 1 The traction control circuit includes a bus and an inverter circuit 102.

[0047] The busbar may be a DC busbar, and of course in some examples it may also be an AC busbar. This application takes the DC busbar as an example for explanation. The external power supply includes a high voltage positive electrode and a high voltage negative electrode. The busbar is connected to the external power supply and receives an electrical signal from the external power supply. Figure 1 The line shown between the external power source and the inverter circuit 102 may be a bus bar.

[0048] The inverter circuit 102 includes a capacitor C1, a first resistor R3 and a switch component connected in series. One end of the inverter circuit 102 is connected to the bus, and the other end is connected to the motor M1. In some embodiments, the inverter circuit 102 includes inverter modules V1 to V6 for converting direct current into alternating current to output to the motor M1. Please continue to refer to Figure 1 , the switch component can be Figure 1 The switch K1 in the Figure 1 Component V7 in the inverter circuit 102 converts the electrical signal from the bus and outputs it to pull the vehicle.

[0049] The first resistor R3 is an original component in the traction control circuit. The first resistor R3 is originally used to realize other functions in the circuit. The first resistor R3 is used as an overvoltage protection resistor or a braking resistor in the original circuit. When used as an overvoltage protection resistor, it absorbs or disperses excess voltage in the circuit to protect other components in the circuit from damage caused by excessive voltage. When used as a braking resistor, it consumes the energy generated during the braking process in the circuit and prevents the generation of excessive back electromotive force. The capacitor needs to be charged before the vehicle runs, so in some cases, the capacitor needs to be discharged for safety reasons. For example, when the first resistor R3 is used as an overvoltage protection resistor or a braking resistor, when the voltage of the inverter circuit is greater than a preset threshold, the voltage of the inverter circuit is, for example, a bus voltage, and the voltage in the inverter circuit is discharged by controlling the conduction of the switch component (such as the second type switch V7). The voltage of the inverter circuit can be the voltage of the external power input or the voltage of the capacitor in the inverter circuit when the external power is disconnected.

[0050] When the capacitor needs to be discharged, the switch component is closed, and the discharge loop formed by the capacitor C1, the first resistor R3 and the switch component is turned on to discharge the voltage of the capacitor C1 through the first resistor R3. It can be seen that for the first resistor R3 originally used as an overvoltage protection resistor or a braking resistor, the first resistor R3 originally in the traction control circuit is used as a component for discharging the capacitor by modifying the control logic in the embodiment of this specification. There is no need to set up an additional resistor for discharging the capacitor, which reduces the cost, and there is no need to add too many additional resistors to discharge the capacitor. Instead, the circuit is logically modified based on the first resistor R3, making the circuit control logic simple and error-prone. In addition, since the first resistor R3 is originally used to discharge when the voltage in the inverter circuit is greater than the preset threshold, the resistance capacity of the first resistor R3 is usually large. Using the first resistor R3 to discharge the voltage of the capacitor C1 can increase the discharge speed and have a better discharge effect.

[0051] In some implementations, the switch component may be manually controlled to close, so that the discharge loop formed by the capacitor C1, the first resistor R3 and the switch component is turned on, so as to discharge the voltage of the capacitor through the first resistor.

[0052] In other embodiments, the switch component may be controlled to close by automatic control so that the discharge loop formed by the capacitor C1, the first resistor R3 and the switch component is turned on to discharge the voltage of the capacitor through the first resistor.

[0053] It should be noted that the circuit principle of the traction control circuit Figure 1 It can also include a high-speed circuit breaker HSCB, an ammeter A1, a reactor L1, and a negative contactor KM3.

[0054] In some embodiments, continue to refer to Figure 1 The switch component includes at least one of a first type switch K1 and a second type switch V7.

[0055] The first type switch and the second type switch are used as switch elements, and the conduction state of the capacitor discharge loop is controlled by closing the switch.

[0056] One end of the first type switch K1 is connected to the busbar, and the other end is connected to the first resistor R3. When the capacitor needs to be discharged, the first type switch K1 is closed, and the capacitor C1, the first resistor R3 and the first type switch K1 form a first discharge loop and the first discharge loop is in a conducting state.

[0057] One end of the second type switch V7 is connected to the busbar, and the other end is connected to the first resistor R3, and is connected in parallel with the first type switch K1, and then connected in series with the first resistor. When the capacitor C1 needs to be discharged, the second type switch V7 is turned on, and the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge circuit and the second discharge circuit is in a conducting state. In the embodiments of this specification, the control circuit is controlled by a variety of switch components, which is convenient for responding to discharge requirements in different scenarios, improves the flexibility of the circuit, and thus realizes more precise control of the capacitor discharge circuit in the traction control circuit.

[0058] For example, the first type switch K1 may be a unipolar mechanical switch, which is simple in design, low in cost, easy to maintain, and can provide intuitive operational feedback and high reliability. The second type switch V7 may be an insulated-gate bipolar transistor (IGBT), which has high-speed switching and the ability to withstand high voltage and high current to provide efficient power control.

[0059] Exemplarily, the inverter circuit 102 includes a first bridge arm, and the first bridge arm includes an upper bridge arm and a lower bridge arm connected to the upper bridge arm. Figure 1 As shown, the upper bridge arm includes an insulated gate bipolar transistor IGBT (V7), and the lower bridge arm includes a diode V8. The insulated gate bipolar transistor IGBT can be used as a second type switch V7. One end of the upper bridge arm is connected to the positive electrode of the bus, one end of the lower bridge arm is connected to the negative electrode of the bus, and the other end of the upper bridge arm and the other end of the lower bridge arm are connected to form a connection point. The connection point between the upper bridge arm and the lower bridge arm is connected to one end of the first resistor R3. For example, one end of the first resistor R3 is connected to the middle of the upper bridge arm and the lower bridge arm, and the other end of the first resistor R3 is connected to the negative electrode of the bus. If the inverter circuit also includes a first type switch K1, the connection point between the upper bridge arm and the lower bridge arm is also connected to one end of the first type switch K1, and the other end of the first type switch K1 is connected to the positive electrode of the bus. The diode V8 includes a positive electrode and a negative electrode, the negative electrode of the diode V8 is connected to the upper bridge arm, and the positive electrode of the diode V8 is connected to the negative electrode of the bus.

[0060] When discharging the capacitor C1, the diode V8 blocks the current from flowing from the cathode of the diode V8 to the anode of the diode V8. Therefore, by connecting the connection point between the upper bridge arm and the lower bridge arm to one end of the first resistor R3 and setting the anode and cathode of the diode V8, when discharging the capacitor C1, the second type switch V7 is turned on, and the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop, so that the discharge current flows through one end of the capacitor C1, the second type switch V7, the connection point between the upper bridge arm and the lower bridge arm, the first resistor R3, and the other end of the capacitor C1, and the current does not flow through the diode.

[0061] Exemplarily, both the upper bridge arm and the lower bridge arm may be IGBTs, which include diodes and transistors, and the upper bridge arm and the lower bridge arm may be packaged together. The IGBT of the lower bridge arm may not be turned on during the capacitor discharge process, so the diode of the lower bridge arm IGBT is arranged in a direction that blocks the current from flowing from the cathode of the diode to the anode of the diode during the discharge process.

[0062] In addition, if Figure 1 As shown, in addition to the first bridge arm, the inverter circuit 102 may also include three other bridge arms, namely, the second bridge arm, the third bridge arm and the fourth bridge arm, which can be used to convert direct current into alternating current, for example. The second bridge arm includes an insulated gate bipolar transistor IGBT (V1) and an insulated gate bipolar transistor IGBT (V4). The third bridge arm includes an insulated gate bipolar transistor IGBT (V2) and an insulated gate bipolar transistor IGBT (V5). The fourth bridge arm includes an insulated gate bipolar transistor IGBT (V3) and an insulated gate bipolar transistor IGBT (V6).

[0063] In the embodiment of this specification, the first type switch K1 is closed to form a first discharge loop, and the second type switch V7 is closed to form a second discharge loop, thereby realizing the function of actively discharging the capacitor by triggering multiple modes, thereby improving the stability and safety of the vehicle's traction control circuit.

[0064] In some embodiments, continue to refer to Figure 1 The traction control circuit also includes a control circuit, and the control circuit includes at least one of an isolating switch QS1 and a traction control unit.

[0065] Both ends of the isolating switch QS1 are connected to the bus, for example, connected in series with the bus. The isolating switch QS1 forms a linkage with the first type switch K1, that is, when the isolating switch QS1 is closed, the first type switch K1 remains in an open state, and when the isolating switch QS1 is disconnected, the first type switch K1 remains in a closed state. Therefore, when the isolating switch QS1 is disconnected, the first type switch K1 is triggered to close, and the discharge circuit is actively connected, so that the capacitor C1, the first resistor R3 and the first type switch K1 form a first discharge circuit and the first discharge circuit is in a conductive state. When the first discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the first discharge circuit, and the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3. In some embodiments, the isolating switch QS1 can be manually disconnected by the maintenance personnel or can also be automatically disconnected by controlling the isolating switch QS1 through a control signal. Therefore, when the capacitor C1 needs to be discharged, the isolating switch QS1 can be disconnected to close the first type switch K1 in linkage.

[0066] The second type switch V7 is used to realize the conduction of the second discharge circuit. Therefore, when the second discharge circuit needs to be conducted or the second discharge circuit is not conducted, a control element or a functional module is required to control the closing of the second type switch V7. Therefore, the closing of the second type switch V7 can be controlled by a traction control unit. In one example, the traction control unit can be a vehicle's automatic transmission control unit (TCU).

[0067] When the capacitor C1 needs to be discharged, the traction control unit controls the second type switch V7 to be turned on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop and the second discharge loop is in a conducting state. When the second discharge loop is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge loop, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is realized through the first resistor R3.

[0068] The traction control unit is an original component in the traction control circuit. The traction control unit is originally used to realize other functions in the circuit. For example, when the transient overvoltage is caused by abnormal conditions such as current taker bounce and voltage spike, and the bus voltage exceeds the preset threshold, the traction control unit controls the second type switch V7 to turn on, and releases the overvoltage energy through the first resistor R3. At this time, the first resistor R3 acts as an overvoltage protection resistor. Or when the vehicle electric braking causes the bus voltage to exceed the preset threshold, the traction control unit controls the second type switch V7 to turn on, and completes the electric braking energy consumption through the first resistor R3. At this time, the first resistor R3 acts as a braking resistor.

[0069] The traction control circuit of the above-mentioned vehicle includes at least one of an isolating switch QS1 and a traction control unit to ensure the safe operation of the traction control circuit.

[0070] In some embodiments, continue to refer to Figure 1 , the traction control circuit may further include a voltage sensor V2.

[0071] When discharging the voltage of capacitor C1, it is necessary to detect the voltage of capacitor C1 to determine whether the voltage of capacitor C1 is lower than the safety voltage to ensure the safety of the circuit and protect components and equipment. Therefore, a voltage sensor V2 is provided in the circuit to detect the voltage of capacitor C1.

[0072] According to the actual situation and needs, a preset time period is pre-set, that is, the length of time that the isolation switch QS1 is disconnected, for example, the preset time period can be 1 minute. After disconnecting the isolation switch QS1, the first type switch K1 is triggered to close, and the discharge circuit is actively connected, so that the first discharge circuit formed by the capacitor C1, the first resistor R3 and the first type switch K1 is turned on. When the first discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the first discharge circuit, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3. After the time for discharging the capacitor C1 reaches the preset time period, the voltage of the capacitor C1 needs to be detected by the voltage sensor V2. It is judged whether the voltage of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage. If the voltage of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage, it means that the discharge operation of the voltage of the capacitor C1 through the first discharge circuit is not completed, which may cause damage to the components in the circuit or pose a danger to the detection personnel. Therefore, when the isolation switch QS1 is turned off for a preset time period and the voltage of the capacitor C1 is not lower than the safety voltage, the second discharge circuit is further turned on to accelerate the discharge speed of the voltage of the capacitor C1. That is, the second type switch V7 is controlled to be turned on, so that the second discharge circuit formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on. When the second discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge circuit, so that the charge stored in the capacitor C1 is discharged, the discharge speed of the voltage of the capacitor C1 is accelerated, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0073] The traction control circuit of the above vehicle includes a voltage sensor for detecting the voltage of the capacitor C1, which provides data support for whether the second type switch V7 needs to be controlled to be turned on, thereby accelerating the discharge speed of the capacitor C1 and reducing the discharge time of the capacitor C1.

[0074] In some embodiments, see Figure 1, the inverter circuit 102 is at least part of the circuit in the inverter. When the opening signal of the inverter is detected, it means that the capacitor C1 needs to be discharged, and it is necessary to ensure that the voltage of the capacitor C1 is lower than the safety voltage. Therefore, when the opening signal of the inverter is detected, it is necessary to detect whether the voltage of the capacitor C1 is lower than the safety voltage through the voltage sensor V2. If the voltage of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage, it may cause damage to the components in the circuit or pose a danger to the detection personnel. Therefore, when the voltage of the capacitor C1 is not lower than the safety voltage, the traction control unit controls the second type switch V7 to turn on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop and the second discharge loop is in a conducting state. When the second discharge loop is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge loop, so that the charge stored in the capacitor C1 is discharged, the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0075] The traction control circuit of the above-mentioned vehicle, when detecting the door opening signal of the inverter, determines whether the voltage of the capacitor C1 detected by the voltage sensor is lower than the safety voltage. If not, the second type switch V7 is controlled to be turned on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3, thereby ensuring the safety of the maintenance personnel's operation.

[0076] In some embodiments, the leakage signal generally indicates that the voltage in the capacitor exceeds the set safety range, which may be caused by capacitor damage, insulation failure or other electrical problems. To prevent potential dangerous situations from occurring, the charge in capacitor C1 needs to be processed quickly. Therefore, when receiving the leakage signal of the traction control circuit, continue to refer to Figure 1 , the traction control unit controls the second type switch V7 to be turned on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop and the second discharge loop is in a conducting state. When the second discharge loop is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge loop, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 gradually decreases, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3. In the process of discharging the voltage of the capacitor C1, the voltage sensor V2 is used to detect the voltage of the capacitor C1. When the voltage of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage, the traction control unit controls the second type switch V7 to be turned off, so that the second discharge loop is disconnected.

[0077] For example, when a vehicle has a leakage or other fault, in order to reduce the impact on operation, it is necessary to quickly complete the leakage location. Before detecting the leakage, it is necessary to use the traction control unit to control the second type switch V7 to turn on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3 until it is determined that the voltage of the capacitor C1 detected by the voltage sensor is lower than the safety voltage. After the voltage of the capacitor C1 detected by the voltage sensor is lower than the safety voltage, the leakage position can be checked and located.

[0078] The traction control circuit of the above-mentioned vehicle, when receiving the leakage signal of the traction control circuit, controls the second type switch V7 to be turned on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3 until it is determined that the voltage of the capacitor C1 detected by the voltage sensor is lower than the safety voltage, thereby protecting electrical components and system equipment and providing a basis for subsequently entering the leakage detection mode.

[0079] Under the premise that the high-speed circuit breaker is disconnected, the disconnecting switch QS1 is in the disconnected state, the inverter door opening signal is detected, and the leakage signal is received, the voltage of the capacitor C1 needs to be actively discharged. The active discharge of the voltage of the capacitor C1 is for emergency situations. It is necessary to quickly complete the discharge operation of the voltage of the capacitor C1, and the first resistor R3 is used to realize the active discharge of the capacitor C1.

[0080] Under the premise that the high-speed circuit breaker is disconnected, when the isolating switch QS1 is in the disconnected state, the first type switch K1 is first triggered to close, so that the capacitor C1, the first resistor R3 and the first type switch K1 form a first discharge loop and the first discharge loop is in the on state. When the first discharge loop is on, the charge of the capacitor C1 flows through the first resistor R3 through the first discharge loop, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the active discharge operation of the voltage of the capacitor C1 is realized through the first resistor R3.

[0081] Under the premise that the high-speed circuit breaker is disconnected, the isolating switch QS1 is in the disconnected state. When the time for discharging the capacitor C1 using the first discharge circuit reaches the preset time period and the voltage of the capacitor C1 is not lower than the safety voltage, it means that the discharge speed of the capacitor C1 by the first discharge circuit is slow, and the discharge speed of the capacitor C1 needs to be accelerated by the second discharge circuit. Specifically, the second type switch V7 is controlled to be turned on, so that the second discharge circuit formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on. When the second discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge circuit, and the charge stored in the capacitor C1 is discharged, which speeds up the discharge speed of the voltage of the capacitor C1, and realizes the active discharge operation of the voltage of the capacitor C1 through the first resistor R3.

[0082] Under the premise that the high-speed circuit breaker is disconnected, when the inverter's door opening signal is detected and the leakage signal is received, the capacitor C1 needs to be discharged using the second discharge circuit. Specifically, the second type switch V7 is controlled to be turned on, so that the second discharge circuit formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on. When the second discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge circuit, and the charge stored in the capacitor C1 is discharged, realizing the active discharge operation of the voltage of the capacitor C1 through the first resistor R3.

[0083] In some embodiments, see Figure 1 The inverter circuit 102 may further include a second resistor R1 connected in parallel with the capacitor C1.

[0084] In some non-emergency situations, such as situations where the discharge speed is not required, the voltage of capacitor C1 can be passively discharged through the second resistor R1, and the second resistor R1 can also be called a passive discharge resistor. Non-emergency situations may include situations where the high-speed circuit breaker is disconnected, the isolating switch QS1 is in a closed state, the inverter is not open, and no leakage signal is detected. When the capacitor needs to be passively discharged, the third discharge circuit formed by the second resistor R1 and the capacitor C1 is turned on. When the third discharge circuit is turned on, the charge of capacitor C1 flows through the second resistor R1 through the third discharge circuit, so as to discharge the charge stored in capacitor C1 and reduce the voltage of capacitor C1, so as to passively discharge the voltage of capacitor C1 through the second resistor R1.

[0085] It should be noted that the resistance value of the resistor determines the speed of discharging the voltage of the capacitor. A larger resistance value will limit the flow of current, resulting in a slower discharge speed; while a smaller resistance value allows a larger current to pass, making the discharge speed faster. Therefore, it is necessary to select a suitable resistance value according to actual needs to control the speed and stability of the discharge process. Since the first resistor R3 acts as an active discharge resistor in the process of discharging the voltage of the capacitor, the passive discharge of the voltage of the capacitor through the first resistor R3 is for emergency situations. The second resistor R1 acts as a passive discharge resistor in the process of discharging the voltage of the capacitor. Passive discharge of the voltage of the capacitor through the second resistor R1 is for non-emergency situations, and the discharge speed is not required. Due to the large capacity resistor, the speed of discharging the voltage of the capacitor is faster, ensuring that the system quickly enters a safe state in an emergency, so the capacity of the second resistor R1 is less than the capacity of the first resistor R3. Since the capacity is inversely proportional to the resistance, the resistance of the second resistor R1 is greater than the resistance of the first resistor R3. Exemplarily, the resistance of the second resistor R1 can be hundreds to thousands of times the resistance of the first resistor R3. For example, the resistance of the second resistor R1 can be 2000 times that of the first resistor R3. For a rail transit vehicle with a DC power supply system and a voltage of 1500 volts, the resistance of the second resistor R1 is 10 kΩ and the resistance of the first resistor R3 is 5 Ω. When the capacitor needs to be discharged and the voltage is reduced to below the safe voltage, it takes about 4 minutes to discharge the capacitor voltage using the second resistor R1, and it takes less than 1 second to discharge the capacitor voltage using the first resistor R3.

[0086] In the traction control circuit of the above vehicle, when the capacitor C1 needs to be discharged, the third discharge loop formed by the second resistor R1 and the capacitor C1 is turned on to discharge the voltage of the capacitor C1 through the second resistor R1, thereby controlling the discharge speed and protecting the equipment and components in the circuit.

[0087] In some embodiments, see Figure 1 The traction control circuit may further include a charging circuit 104, the charging circuit 104 includes a first contactor KM1, a second contactor KM2, and a third resistor RL, the first contactor KM1 is connected in series with the bus, the second contactor KM2 is connected in series with the third resistor RL, and is connected in parallel with the first contactor KM1.

[0088] Both ends of the charging circuit 104 are connected to the busbar. Both ends of the first contactor KM1 are connected to the busbar; one end of the second contactor KM2 is connected to the busbar, and the other end is connected to the third resistor RL; one end of the third resistor RL is connected to the busbar, and the other end is connected to the third resistor second contactor KM2. The third resistor RL and the second contactor KM2 are connected in series and then connected in parallel with the first contactor KM1.

[0089] In some vehicles, especially hybrid vehicles or electric vehicles, capacitors are used as energy storage devices for starting auxiliary systems. The capacitor is charged to ensure that sufficient electrical energy can be provided to start the engine or other key systems when the vehicle is started. Therefore, the capacitor C1 needs to be charged before the vehicle is running. When charging the capacitor C1, if the first contactor KM1 is closed and the second contactor KM2 is disconnected, a large instantaneous current will flow through the capacitor C1, causing damage to the circuit and the capacitor C1 itself. Therefore, when charging the capacitor C1 using the charging circuit, it is necessary to disconnect the first contactor KM1 and close the second contactor KM2, so that the charging circuit 104 and the external power supply are connected to the circuit through the high-voltage positive electrode and the high-voltage negative electrode and the circuit formed by the capacitor C1 is turned on. When the circuit is turned on, the charging current flows out from the external power supply through the second contactor KM2 and the third resistor RL in the charging circuit 104, and the third resistor RL in the charging circuit 104 is used to reduce the charging current, and then flows into the capacitor C1 to charge the capacitor C1. The third resistor RL and the second contactor KM2 are connected in series and then connected in parallel with the first contactor KM1, which can be applied to different situations to provide different control and protection functions for the circuit. It should be noted that after the capacitor C1 is charged, the first contactor KM1 is closed and the second contactor KM2 is opened.

[0090] In the traction control circuit of the above-mentioned vehicle, the charging circuit is used to charge the capacitor C1 before the vehicle is running to facilitate the traction of the vehicle. When the capacitor C1 needs to be discharged, the residual voltage in the capacitor C1 provides a basis for the subsequent discharge of the capacitor voltage.

[0091] In some embodiments, the traction control circuit inverter circuit includes at least two inverter circuits, that is, the inverter circuit may include multiple inverter circuits. Figure 1 One is shown, and two, three, etc. may also be included. The embodiments of this specification are described by taking two as an example. Figure 2 The inverter circuit includes a first inverter circuit 202 and a second inverter circuit 204 .

[0092] The second inverter circuit 204 includes inverter modules V9 to V14 for converting DC power into AC power for output to the motor M2. The first inverter circuit 202 has the same structure as the inverter circuit 102 in the above embodiment, and the second inverter circuit 204 also has the same or similar structure as the inverter circuit 102 in the above embodiment.

[0093] Specifically, when the inverter circuit includes two inverter circuits, redundant backup of the discharge circuit can be achieved. That is, when one inverter circuit fails, the other inverter circuit can take over and continue the discharge operation. That is, when the capacitor C1 in the first inverter circuit needs to be discharged, the switch component in the second inverter circuit is closed, so that the capacitor C1 in the first inverter circuit, the first resistor R4 in the second inverter circuit and the switch component in the second inverter circuit form a discharge circuit that is turned on, and the current flows out of the capacitor C1 in the first inverter circuit through the first resistor R4 in the second inverter circuit, and the charge stored in the capacitor C1 in the first inverter circuit is discharged, and the voltage of the capacitor C1 in the first inverter circuit is reduced, so as to discharge the voltage of the capacitor C1 in the first inverter circuit through the first resistor R4 in the second inverter circuit.

[0094] In some embodiments, see Figure 2 When the capacitor C1 needs to be discharged, the first type switch K1 in the first inverter circuit 202 fails and cannot be closed, and a discharge path cannot be provided. However, the first type switch K2 or the second type switch V15 in the second inverter circuit 204 is normal and in a closed state, then the capacitor C1 in the first inverter circuit 202, the first resistor R4 in the second inverter circuit 204, and the first type switch K2 or the second type switch V15 in the second inverter circuit 204 form a discharge loop and the discharge loop is in a conductive state. When the discharge loop is conductive, the charge of the capacitor C1 flows through the first resistor R4 in the second inverter circuit 204 through the discharge loop, so that the charge stored in the capacitor C1 in the first inverter circuit 202 is discharged, so that the voltage of the capacitor C1 in the first inverter circuit 202 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 in the first inverter circuit 202 is performed through the first resistor R4 in the second inverter circuit 204.

[0095] In some other embodiments, see Figure 2When the capacitor C1 needs to be discharged, the second type switch V7 in the first inverter circuit 202 fails, causing the traction control unit to be unable to control the second type switch V7 to be turned on, thereby failing to discharge the voltage of the capacitor C1 in the first inverter circuit 202. However, the first type switch K2 or the second type switch V15 in the second inverter circuit 204 is normal, and the first type switch K2 or the second type switch V15 is turned on, so that the capacitor C1 in the first inverter circuit 202, the first resistor R4 in the second inverter circuit 204, and the first type switch K2 or the second type switch V15 in the second inverter circuit 204 form a discharge loop, and the discharge loop is in a conducting state. When the discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R4 in the second inverter circuit 204 through the discharge circuit, thereby discharging the charge stored in the capacitor C1 in the first inverter circuit 202, so that the voltage of the capacitor C1 in the first inverter circuit 202 gradually decreases, thereby realizing the discharge operation of the voltage of the capacitor C1 in the first inverter circuit 202 through the first resistor R4 in the second inverter circuit 204.

[0096] It should be noted that when it is necessary to discharge the capacitor C2 in the second inverter circuit, the discharge circuit formed by the capacitor C2 in the second inverter circuit, the first resistor R3 in the first inverter circuit and the switch component in the first inverter circuit can also be turned on to discharge the voltage of the capacitor C2 in the second inverter circuit through the first resistor R3 in the first inverter circuit.

[0097] Exemplarily, the isolation switch QS1 forms a linkage with the first type switch K1 and the first type switch K2. Ideally, the first type switch K1 and the first type switch K2 should be in a closed state at the same time. If the first type switch K1 in the first inverter circuit 202 fails and cannot be closed, and a discharge loop cannot be formed, while the first type switch K2 in the second inverter circuit 204 is normal and in a closed state, the capacitor C1 in the first inverter circuit 202, the first resistor R4 in the second inverter circuit 204, and the first type switch K2 in the second inverter circuit 204 form a discharge loop and are turned on to realize the discharge operation of the voltage of the capacitor C1 in the first inverter circuit 202 through the first resistor R4 in the second inverter circuit 204.

[0098] It should be noted that the first type switch K1 and the first type switch K2 can be in a closed state at the same time, the capacitor C1 in the first inverter circuit 202, the first resistor R3 in the first inverter circuit 202, and the discharge loop formed by the first type switch K1 in the first inverter circuit 202 are turned on, and the capacitor C1 in the first inverter circuit 202, the first resistor R4 in the second inverter circuit 204, and the first type switch K2 in the second inverter circuit 204 form a discharge loop that is turned on, and the voltage of the capacitor C1 in the first inverter circuit 202 can be discharged by the first resistor R3 in the first inverter circuit 202 and the first resistor R4 in the second inverter circuit 204 at the same time. Similarly, the voltage of the capacitor C1 in the second inverter circuit 204 can be discharged by the first resistor R3 in the first inverter circuit 202 and the first resistor R4 in the second inverter circuit 204 at the same time.

[0099] The traction control unit can control the second type switch V7 and the second type switch V15 to be turned on at the same time. When the capacitor C1 needs to be discharged, the second type switch V7 in the first inverter circuit 202 fails, resulting in the traction control unit being unable to control the second type switch V7 to be turned on. The second type switch V15 in the second inverter circuit 204 is normal. The second type switch V15 is turned on to form a discharge loop for the capacitor C1 in the first inverter circuit 202, the first resistor R4 in the second inverter circuit 204, and the second type switch V15 in the second inverter circuit 204, and the discharge loop is in a conducting state, thereby realizing the discharge operation of the voltage of the capacitor C1 in the first inverter circuit 202 through the first resistor R4 in the second inverter circuit 204.

[0100] It should be noted that the second type switch V7 and the second type switch V15 can be in a closed state at the same time, the capacitor C1 in the first inverter circuit 202, the first resistor R3 in the first inverter circuit 202 and the discharge loop formed by the second type switch V7 in the first inverter circuit 202 are turned on, and the capacitor C1 in the first inverter circuit 202, the first resistor R4 in the second inverter circuit 204 and the second type switch V15 in the second inverter circuit 204 form a discharge loop that is turned on, thereby realizing the discharge operation of the voltage of the capacitor C1 in the first inverter circuit 202 through the first resistor R3 in the first inverter circuit 202 and the first resistor R4 in the second inverter circuit 204.

[0101] In the traction control circuit of the above-mentioned vehicle, when it is necessary to discharge the capacitor, the discharge loop formed by the capacitor C1 in the first inverter circuit, the first resistor R4 in the second inverter circuit and the switch component in the second inverter circuit is turned on to discharge the voltage of the capacitor C1 in the first inverter circuit through the first resistor R4 in the second inverter circuit, so as to ensure the reliability and stability of the traction control circuit and improve the safety of the traction control circuit.

[0102] The embodiment of this specification provides a discharge control method for a vehicle traction system. The discharge control method is applied to a traction control circuit according to any of the above embodiments. Figure 3 , the discharge control method may include the following steps:

[0103] S310, detecting a discharge demand signal of capacitor C1 in the traction control circuit.

[0104] S320. When it is determined based on the discharge demand signal that the capacitor C1 needs to be discharged, the switch component is controlled to close so that the discharge loop formed by the capacitor C1, the first resistor R3 and the switch component is turned on to discharge the voltage of the capacitor C1 through the first resistor R3.

[0105] The discharge requirement signal may be a signal used by the traction control circuit to determine whether the capacitor needs to be discharged.

[0106] In some cases, for emergency situations, it is necessary to quickly discharge the voltage of the capacitor C1. In the process of discharging the voltage of the capacitor C1 through the first resistor R3, the first resistor R3 acts as an active discharge resistor to achieve active discharge of the voltage of the capacitor C1. The emergency situation may be when the high-speed circuit breaker is disconnected, the isolation switch QS1 is in a closed state, the inverter opening signal is detected, or the leakage signal is received.

[0107] Specifically, a discharge demand signal is generated when the capacitor in the traction control circuit needs to be discharged. Therefore, the discharge demand signal of the traction control circuit is detected, and when the discharge demand signal in the traction control circuit is detected, it is determined that the capacitor C1 needs to be discharged. When it is determined that the capacitor C1 needs to be discharged, the control circuit controls the switch component in the traction control circuit to close, so that the capacitor C1, the first resistor R3 and the switch component form a discharge loop and the discharge loop is in a conductive state. When the discharge loop is conductive, the charge of the capacitor C1 flows through the first resistor R3 through the discharge loop, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0108] In the discharge control method of the vehicle traction system, a discharge demand signal of the capacitor C1 in the traction control circuit is detected. When it is determined that the capacitor C1 needs to be discharged based on the discharge demand signal, the switch component is controlled to close, so that the discharge loop formed by the capacitor C1, the first resistor R3 and the switch component is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3. The first resistor R3 is used as a component for discharging the capacitor C1. There is no need to set an additional resistor for discharging the capacitor C1, and the resistance capacity of the first resistor R3 is large, which can increase the discharge speed and achieve a better discharge effect.

[0109] In some embodiments, the discharge demand signal includes a signal indicating whether the isolating switch connected in series with the busbar is disconnected. Of course, the discharge demand signal may also indicate whether both the high-speed circuit breaker and the isolating switch are disconnected. The switch component includes a first type switch, and the isolating switch forms a linkage with the first type switch. When it is determined based on the discharge demand signal that the capacitor needs to be discharged, controlling the switch component to close may include:

[0110] When the discharge demand signal indicates that the isolating switch QS1 is disconnected, or when the discharge demand signal indicates that both the high-speed circuit breaker and the isolating switch QS1 are disconnected, the first type switch K1 is triggered to close, so that the first discharge loop formed by the capacitor C1, the first resistor R3 and the first type switch K1 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3.

[0111] Specifically, when the discharge demand signal indicates that the isolation switch QS1 is disconnected, the first type switch K1 is triggered to close, and the discharge circuit is actively connected, so that the capacitor C1, the first resistor R3 and the first type switch K1 form a first discharge circuit and the first discharge circuit is in a conductive state. When the first discharge circuit is conductive, the charge of the capacitor C1 flows through the first resistor R3 through the first discharge circuit, so that the charge stored in the capacitor C1 is discharged, the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3. In some embodiments, the isolation switch QS1 can be manually disconnected by maintenance personnel.

[0112] In the above-mentioned discharge control method of the vehicle traction system, when the discharge demand signal indicates that the isolation switch QS1 is disconnected, the first type switch K1 is triggered to close, so that the first discharge loop formed by the capacitor C1, the first resistor R3 and the first type switch K1 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3, so as to ensure the safe operation of the traction control circuit.

[0113] In some embodiments, the switch component includes a second type switch, and the discharge requirement signal includes a signal indicating whether the traction control unit generates a signal to control the second type switch to be turned on. When it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to be closed may include:

[0114] When the discharge demand signal indicates that the traction control unit generates a signal to control the second type switch V7 to be turned on, the second type switch V7 is controlled to be turned on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3.

[0115] Specifically, when the discharge demand signal indicates that the traction control unit generates a signal for controlling the second type switch V7 to be turned on, the traction control unit controls the second type switch V7 to be turned on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop and the second discharge loop is in a conducting state. When the second discharge loop is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge loop, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0116] In the above-mentioned discharge control method of the vehicle traction system, when the discharge demand signal indicates that the traction control unit generates a signal to control the second type switch V7 to be turned on, the second type switch V7 is controlled to be turned on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3, so as to ensure the safe operation of the traction control circuit.

[0117] In some embodiments, see Figure 4 The switch component includes a first type switch and a second type switch; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close may include the following steps:

[0118] S410. When it is determined based on the discharge demand signal that the capacitor C1 needs to be discharged, the isolating switch QS1 connected in series with the bus is disconnected and triggers the first type switch K1 to close, so that the first discharge loop formed by the capacitor C1, the first resistor R3 and the first type switch K1 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3.

[0119] S420 , after the isolation switch QS1 is turned off for a preset period of time, determine whether the voltage of the capacitor C1 is lower than a safety voltage.

[0120] S430 , if not, control the second type switch V7 to be turned on, so that the second discharge loop formed by the capacitor C1 , the first resistor R3 , and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3 .

[0121] Specifically, when it is determined based on the discharge demand signal that the capacitor needs to be discharged, when the isolation switch QS1 is disconnected, the first type switch K1 is triggered to close, and the discharge circuit is actively connected, so that the capacitor C1, the first resistor R3 and the first type switch K1 form a first discharge circuit and the first discharge circuit is in a conducting state. When the first discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the first discharge circuit, so that the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3. After disconnecting the isolation switch QS1, the length of time it is disconnected is determined. After determining that the isolation switch QS1 is disconnected for a preset time period, the traction control unit needs to detect whether the voltage of the capacitor C1 is lower than the safety voltage through the voltage sensor. If the voltage of the capacitor C1 detected by the voltage sensor is not lower than the safety voltage, it may cause damage to the components in the circuit or pose a danger to the detection personnel. Therefore, when the voltage of the capacitor C1 is not lower than the safety voltage, the traction control unit controls the second type switch V7 to be turned on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop and the second discharge loop is in a conducting state. When the second discharge loop is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge loop, so that the charge stored in the capacitor C1 is discharged, the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0122] In the above-mentioned discharge control method of the vehicle traction system, when it is determined based on the discharge demand signal that the capacitor C1 needs to be discharged, the isolating switch QS1 connected to the bus is disconnected and triggers the first type switch K1 to close, so that the first discharge circuit formed by the capacitor C1, the first resistor R3 and the first type switch K1 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3. After the isolating switch QS1 is disconnected for a preset time period, it is determined whether the voltage of the capacitor C1 is lower than the safety voltage. If not, the second type switch V7 is controlled to be turned on, so that the second discharge circuit formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3, thereby ensuring the safety of the maintenance personnel's operation.

[0123] In some embodiments, see Figure 5, the switch component includes a second type switch, the inverter circuit is at least a part of the circuit in the inverter, and the discharge demand signal includes a signal indicating whether the inverter is open; when it is determined based on the discharge demand signal that the capacitor needs to be discharged, controlling the switch component to close may include the following steps:

[0124] S510 . When it is determined based on the discharge demand signal that the inverter is opened, determine whether the voltage of the capacitor C1 is lower than a safety voltage.

[0125] S520 , if not, control the second type switch V7 to be turned on, so that the second discharge loop formed by the capacitor C1 , the first resistor R3 , and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3 .

[0126] Specifically, when the traction control circuit detects the opening signal of the inverter, or when the high-speed circuit breaker is disconnected and the traction control circuit detects the opening signal of the inverter, it is necessary to ensure that the voltage of the capacitor C1 is lower than the safety voltage. Therefore, when the opening signal of the inverter is detected, it is necessary to detect whether the voltage of the capacitor C1 is lower than the safety voltage through the voltage sensor. If the voltage of the capacitor C1 detected by the voltage sensor is not lower than the safety voltage, it may cause damage to the components in the circuit or pose a danger to the detection personnel. Therefore, when the voltage of the capacitor C1 is not lower than the safety voltage, the traction control unit controls the second type switch V7 to turn on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge circuit and the second discharge circuit is in a conducting state. When the second discharge circuit is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge circuit, so that the charge stored in the capacitor C1 is discharged, the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0127] In the discharge control method of the above-mentioned vehicle traction system, when it is determined that the inverter is open based on the discharge demand signal, it is determined whether the voltage of the capacitor C1 is lower than the safety voltage. If not, the second type switch V7 is controlled to be turned on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3, thereby ensuring the safety of the maintenance personnel's operation.

[0128] In some embodiments, see Figure 6 , the switch component includes a second type switch, the discharge requirement signal includes a signal indicating whether the traction control circuit has leakage; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close may include the following steps:

[0129] S610 . When it is determined based on the discharge demand signal that the traction control circuit is leaking, determine whether the voltage of the capacitor C1 is lower than a safety voltage.

[0130] S620 , if not, control the second type switch V7 to be turned on, so that the second discharge loop formed by the capacitor C1 , the first resistor R3 , and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3 .

[0131] Specifically, in the case where the traction control circuit is leaking based on the discharge demand signal, or in the case where the high-speed circuit breaker is disconnected and the traction control circuit is leaking based on the discharge demand signal, the voltage sensor is used to detect whether the voltage of the capacitor C1 is lower than the safety voltage. When the voltage of the capacitor C1 detected by the voltage sensor is not lower than the safety voltage, the traction control unit controls the second type switch V7 to turn on, so that the capacitor C1, the first resistor R3 and the second type switch V7 form a second discharge loop and the second discharge loop is in a conducting state. When the second discharge loop is turned on, the charge of the capacitor C1 flows through the first resistor R3 through the second discharge loop, so that the charge stored in the capacitor C1 is discharged, the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0132] In the above-mentioned discharge control method of the vehicle traction system, when it is determined that the traction control circuit is leaking based on the discharge demand signal, it is determined whether the voltage of the capacitor C1 is lower than the safety voltage. If not, the second type switch V7 is controlled to be turned on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3, protect the electrical components and system equipment, and provide a basis for subsequently entering the leakage detection mode.

[0133] In some embodiments, the inverter circuit also includes a second resistor R1 connected in parallel with the capacitor C1, the resistance of the second resistor R1 is greater than the resistance of the first resistor R3, and the discharge demand signal includes an indication of whether the traction control circuit has been stopped from being powered by the external power supply; the discharge control method may further include: when it is determined based on the discharge demand signal that the traction control circuit has been stopped from being powered by the external power supply, a third discharge loop formed by the second resistor R1 and the capacitor C1 is turned on, and the voltage of the capacitor C1 is discharged through the second resistor R1.

[0134] Specifically, when it is determined based on the discharge demand signal that the power supply to the traction control circuit by the external power supply has stopped, the third discharge loop formed by the second resistor R1 as a passive discharge resistor and the capacitor C1 is turned on. When the third discharge loop is turned on, current flows out of the capacitor C1 through the second resistor R1, discharges the charge stored in the capacitor C1, reduces the voltage of the capacitor C1, and discharges the voltage of the capacitor C1 through the second resistor R1.

[0135] In the above-mentioned discharge control method of the vehicle traction system, when it is determined based on the discharge demand signal that the power supply to the traction control circuit through the external power supply has stopped, the third discharge loop formed by the second resistor R1 and the capacitor C1 is turned on, and the voltage of the capacitor C1 is discharged through the second resistor R1, so as to control the discharge speed and protect the equipment and components in the circuit.

[0136] In some embodiments, the inverter circuit includes a first inverter circuit and a second inverter circuit. When it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close may include:

[0137] When it is determined based on the discharge demand signal that the capacitor needs to be discharged, at least the switch component in the second inverter circuit is controlled to close, so that the discharge loop formed by the capacitor in the first inverter circuit, the first resistor in the second inverter circuit and the switch component in the second inverter circuit is turned on, so as to discharge the voltage of the capacitor in the first inverter circuit through the first resistor in the second inverter circuit.

[0138] Specifically, when a discharge demand signal is detected to determine that the capacitor needs to be discharged, the switch component in the first inverter circuit is not closed or the discharge path including the switch component in the first inverter circuit cannot be provided due to a switch component failure. When the switch component in the second inverter circuit is normal, the switch component in the second inverter circuit is controlled to be closed, so that the capacitor C1 in the first inverter circuit, the first resistor R4 in the second inverter circuit, and the first type switch K2 in the second inverter circuit form a discharge loop and the discharge loop is in a conductive state. When the discharge loop is conductive, the charge of the capacitor C1 flows through the first resistor R4 in the second inverter circuit through the discharge loop, so that the charge stored in the capacitor C1 in the first inverter circuit is discharged, so that the voltage of the capacitor C1 in the first inverter circuit is gradually reduced, and the discharge operation of the voltage of the capacitor C1 in the first inverter circuit is performed through the first resistor R4 in the second inverter circuit.

[0139] In the above-mentioned discharge control method of the vehicle traction system, when it is determined based on the discharge demand signal that the capacitor needs to be discharged, at least the switch component in the second inverter circuit is controlled to be closed, so that the discharge loop formed by the capacitor C1 in the first inverter circuit, the first resistor R4 in the second inverter circuit and the switch component in the second inverter circuit is turned on, so as to discharge the voltage of the capacitor C1 in the first inverter circuit through the first resistor R4 in the second inverter circuit, so as to ensure the reliability and stability of the traction control circuit and improve the safety of the traction control circuit.

[0140] The embodiment of the present specification provides an inverter, the inverter includes an inverter circuit, the inverter circuit is connected to the bus, the inverter circuit is used to convert the electrical signal from the bus and output it to tow the vehicle; the inverter circuit includes a capacitor, a first resistor and a switch component, the capacitor is connected in series with the bus; the first resistor and the switch component are connected in series and in parallel with the capacitor, and the first resistor is used to discharge when the voltage in the inverter circuit is greater than a preset threshold. When the capacitor needs to be discharged, the switch component is closed, and the discharge circuit formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor.

[0141] Specifically, the first resistor R3 is an original component in the traction control circuit. The first resistor R3 is originally used to realize other functions in the circuit. The first resistor R3 is used as an overvoltage protection resistor in the original circuit. When the voltage of the capacitor C1 is greater than a preset threshold, the first resistor R3 is used to discharge the voltage of the capacitor C1. The first resistor R3 can also be used as a braking resistor in the original circuit.

[0142] When the capacitor C1 needs to be discharged, the control circuit controls the switch component in the traction control circuit to close, so that the capacitor C1, the first resistor R3 and the switch component form a discharge loop and the discharge loop is in a conducting state. When the discharge loop is conducting, the charge of the capacitor C1 flows through the first resistor R3 through the discharge loop, and the charge stored in the capacitor C1 is discharged, so that the voltage of the capacitor C1 is gradually reduced, and the discharge operation of the voltage of the capacitor C1 is performed through the first resistor R3.

[0143] In the above embodiment, when the capacitor C1 needs to be discharged, the switch component is closed, and the discharge loop formed by the capacitor C1, the first resistor R3 and the switch component is turned on to discharge the voltage of the capacitor C1 through the first resistor R3. The first resistor R3 has a large resistance capacity, which can achieve a faster discharge speed, and the heat dissipation condition is good, and no excessive heat is generated. The first resistor R3, which was originally used as an overvoltage protection resistor or a braking resistor, is used as a component for discharging the capacitor C1, and there is no need to set an additional resistor for discharging the capacitor C1, which reduces the cost. The resistance capacity of the first resistor R3 is large, which can increase the discharge speed and has a better discharge effect.

[0144] The embodiments of the present specification also provide a discharge control method for a vehicle traction system, and a traction control circuit corresponding to the discharge control method for the vehicle traction system takes an inverter circuit as an example.

[0145] For example, see Figure 7 Before the vehicle is running, the capacitor C1 is charged through the charging circuit. When the high-speed circuit breaker HSCB is disconnected and the high voltage of the vehicle is de-energized, it is determined whether the isolation switch QS1 is switched to the cut-off position.

[0146] When the isolation switch QS1 is disconnected, the control circuit controls the first type switch K1 to close, so that the first discharge loop formed by the capacitor C1, the first resistor R3 and the first type switch K1 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3 to perform active discharge.

[0147] The traction control unit detects the state of the isolating switch QS1 and the voltage of the capacitor C1 detected by the voltage sensor V2 in real time. When the traction control unit determines that the isolating switch QS1 is always in the disconnected state and the isolating switch is disconnected for a preset time period, it determines whether the voltage U1 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua. If the voltage U1 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua, the traction control unit determines that the active discharge of the capacitor C1 is completed. If the voltage U1 of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage Ua, the traction control unit controls the second type switch V7 to turn on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on, so as to discharge the voltage of the capacitor C1 through the first resistor R3. Then it is determined again whether the voltage U2 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua. If the voltage U2 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua, the traction control unit controls the second type switch V7 to turn off to stop the active discharge of the capacitor C1. If the voltage U2 of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage Ua, the discharge continues through the second discharge circuit until the voltage U2 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua.

[0148] When the isolating switch QS1 is closed, it is determined whether the traction control unit detects the inverter's door opening signal. When the inverter's door opening signal is detected, the traction control unit determines whether the voltage U3 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua. If the voltage U3 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua, the traction control unit determines that the active discharge of the capacitor C1 is completed. If the voltage U3 of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage Ua, the traction control unit controls the second type switch V7 to turn on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3. Then it is determined again whether the voltage U4 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua. If the voltage U4 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua, the traction control unit controls the second type switch V7 to turn off to stop the active discharge of the capacitor C1. If the voltage U4 of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage Ua, the discharge continues through the second discharge circuit until the voltage U4 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua.

[0149] When the inverter door opening signal is not detected, it is determined whether the traction control unit receives the leakage signal of the traction control circuit. When the leakage signal of the traction control circuit is received, the traction control unit controls the second type switch V7 to turn on, so that the second discharge loop formed by the capacitor C1, the first resistor R3 and the second type switch V7 is turned on to discharge the voltage of the capacitor C1 through the first resistor R3. Then it is determined whether the voltage U5 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua. If the voltage U5 of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua, the traction control unit controls the second type switch V7 to turn off to stop the active discharge of the capacitor C1. If the voltage U5 of the capacitor C1 detected by the voltage sensor V2 is not lower than the safety voltage Ua, the discharge continues through the second discharge loop until the voltage of the capacitor C1 detected by the voltage sensor V2 is lower than the safety voltage Ua.

[0150] When the inverter opening signal is not detected and the capacitor C1 needs to be discharged, the third discharge loop formed by the second resistor R1 and the capacitor C1 is turned on to discharge the voltage of the capacitor C1 through the second resistor R1. The second resistor R1 is greater than the resistance of the first resistor R3.

[0151] An embodiment of the present specification provides a high-voltage box, which includes any one of the above-mentioned traction control circuits.

[0152] An embodiment of the present specification provides a vehicle, the vehicle includes any one of the traction control circuits described above, or the vehicle is used to implement any one of the steps of the discharge control method described above, or the vehicle includes the inverter described above, or the vehicle includes the high-voltage box described above.

[0153] The embodiment of this specification provides an electronic device, which may be a terminal, and its internal structure diagram may be as follows: Figure 8As shown. The electronic device includes a processor, a memory, a communication interface, a display screen and an input device connected through a system bus. Among them, the processor of the electronic device is used to provide computing and control capabilities. The memory of the electronic device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The communication interface of the electronic device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be achieved through WIFI, an operator network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a discharge control method for a vehicle traction system is implemented. The display screen of the electronic device can be a liquid crystal display screen or an electronic ink display screen, and the input device of the electronic device can be a touch layer covered on the display screen, or a key, trackball or touchpad set on the housing of the electronic device, or an external keyboard, touchpad or mouse.

[0154] Those skilled in the art will understand that Figure 8 The structure shown in the figure is merely a block diagram of a portion of the structure related to the scheme disclosed in this specification, and does not constitute a limitation on the electronic device to which the scheme disclosed in this specification is applied. Specifically, the electronic device may include more or fewer components than shown in the figure, or combine certain components, or have a different arrangement of components.

[0155] An embodiment of the present specification provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the method steps in the above embodiment when executing the computer program.

[0156] An embodiment of the present specification provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, the steps of the method in any of the above embodiments are implemented.

[0157] The embodiments of this specification provide a computer program product, which includes instructions. When the instructions are executed by a processor of a computer device, the computer device can perform the steps of any method of the above embodiments.

[0158] It should be noted that the logic and / or steps represented in the flowchart or described in other ways herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by an instruction execution system, device or equipment (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or equipment and execute instructions), or in combination with these instruction execution systems, devices or equipment. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or equipment, or in combination with these instruction execution systems, devices or equipment. More specific examples (non-exhaustive list) of computer-readable media include the following: an electrical connection portion with one or more wirings (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and editable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or otherwise processing in a suitable manner if necessary, and then stored in a computer memory.

Claims

1. A traction control circuit for a vehicle, characterized in that: The traction control circuit includes at least two inverter circuits, and the traction control circuit includes: A bus bar, used for receiving an electrical signal from an external power source; an inverter circuit connected to the bus, the inverter circuit being used to convert and output the electrical signal from the bus to tow the vehicle; wherein the inverter circuit comprises a capacitor, a first resistor and a switch component; the capacitor is connected in series with the bus; the first resistor and the switch component are connected in series and in parallel with the capacitor, the first resistor being used to discharge when the voltage in the inverter circuit is greater than a preset threshold, and at least two of the inverter circuits comprising a first inverter circuit and a second inverter circuit; in, When it is necessary to discharge the capacitor in the first inverter circuit, a discharge loop formed by the capacitor in the first inverter circuit, the first resistor in the second inverter circuit, and the switch component in the second inverter circuit is turned on to discharge the voltage of the capacitor in the first inverter circuit through the first resistor in the second inverter circuit; When it is necessary to discharge the capacitor in the second inverter circuit, at least the switch component in the first inverter circuit is controlled to be closed, so that the discharge loop formed by the capacitor in the second inverter circuit, the first resistor in the first inverter circuit and the switch component in the first inverter circuit is turned on, so as to discharge the voltage of the capacitor in the second inverter circuit through the first resistor in the first inverter circuit.

2. The traction control circuit according to claim 1, characterized in that: The switch component includes at least one of a first type switch and a second type switch; After the first type switch is closed, a first discharge loop formed by the capacitor, the first resistor and the first type switch is turned on; After the second type switch is turned on, a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on; Wherein, in the case that the switch component includes both the first type switch and the second type switch, the first type switch and the second type switch are connected in parallel and connected in series with the first resistor.

3. The traction control circuit according to claim 2, characterized in that: The inverter circuit includes a first bridge arm, the first bridge arm includes an upper bridge arm and a lower bridge arm connected to the upper bridge arm, one end of the upper bridge arm is connected to the positive electrode of the bus, and one end of the lower bridge arm is connected to the negative electrode of the bus; the connection point between the upper bridge arm and the lower bridge arm is connected to one end of the first resistor, and the other end of the first resistor is connected to the negative electrode of the bus; the upper bridge arm includes an insulated gate bipolar transistor IGBT, the insulated gate bipolar transistor IGBT serves as the second type switch, and the lower bridge arm includes a diode, the cathode of the diode is connected to the upper bridge arm, and the anode of the diode is connected to the negative electrode of the bus.

4. The traction control circuit according to claim 2, characterized in that: The traction control circuit further includes a control circuit; the control circuit includes at least one of the following: an isolating switch connected in series with the busbar and linked with the first type switch, and triggering the first type switch to close when the isolating switch is disconnected, so that the first discharge circuit formed by the capacitor, the first resistor and the first type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor; A traction control unit is connected to the second type switch, and the traction control unit is used to control the second type switch to be turned on, so that the second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

5. The traction control circuit according to claim 4, characterized in that: The traction control circuit further includes: A voltage sensor, used for detecting the voltage of the capacitor; The traction control unit is further used to determine whether the voltage of the capacitor detected by the voltage sensor is lower than the safety voltage after the isolating switch is disconnected for a preset time period. If not, the traction control unit controls the second type switch to be turned on so that the second discharge circuit formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

6. The traction control circuit according to claim 5, characterized in that: The inverter circuit is at least a part of the circuit in the inverter; the traction control unit is also used for: When the opening signal of the inverter is detected, it is determined whether the voltage of the capacitor detected by the voltage sensor is lower than the safety voltage. If not, the second type switch is controlled to be turned on, so that the second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

7. The traction control circuit according to claim 5, characterized in that: The traction control unit is also used for: When a leakage signal from the traction control circuit is received, the second type switch is controlled to be turned on, so that the second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor until it is determined that the voltage of the capacitor detected by the voltage sensor is lower than the safety voltage.

8. The traction control circuit according to claim 5, characterized in that: The inverter circuit also includes: a second resistor, connected in parallel with the capacitor, wherein the resistance of the second resistor is greater than the resistance of the first resistor; When the capacitor needs to be discharged, a third discharge loop formed by the second resistor and the capacitor is turned on to discharge the voltage of the capacitor through the second resistor.

9. The traction control circuit according to any one of claims 1 to 8, characterized in that: The traction control circuit further includes: A charging circuit, connected in series with the bus bar, for charging the capacitor before the vehicle is operated; Wherein, the charging circuit includes a first contactor, a second contactor and a third resistor; the first contactor is connected in series with the busbar; the second contactor is connected in series with the third resistor and connected in parallel with the first contactor: Wherein, when the capacitor is charged through the charging circuit, the first contactor is opened and the second contactor is closed.

10. A discharge control method for a vehicle traction system, characterized in that: The discharge control method is applied to the traction control circuit according to any one of claims 1 to 9, and the discharge control method comprises: detecting a discharge demand signal of a capacitor in the traction control circuit; When it is determined based on the discharge demand signal that the capacitor needs to be discharged, the switch component is controlled to be closed so that a discharge loop formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor.

11. The discharge control method according to claim 10, characterized in that: The discharge requirement signal includes a signal indicating whether the isolating switch connected in series with the bus is disconnected, the switch component includes a first type switch, and the isolating switch forms a linkage with the first type switch; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close includes: When the discharge demand signal indicates that the isolation switch is disconnected, the first type switch is triggered to close, so that a first discharge loop formed by the capacitor, the first resistor and the first type switch is turned on to discharge the voltage of the capacitor through the first resistor.

12. The discharge control method according to claim 10, characterized in that: The switch component includes a second type switch, the discharge requirement signal includes a signal indicating whether the traction control unit generates a signal to control the second type switch to be turned on; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to be closed includes: When the discharge demand signal indicates that the traction control unit generates a signal to control the second type switch to be turned on, the second type switch is controlled to be turned on so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on to discharge the voltage of the capacitor through the first resistor.

13. The discharge control method according to claim 10, characterized in that: The switch component includes a first type switch and a second type switch; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close includes: When it is determined based on the discharge demand signal that the capacitor needs to be discharged, the isolating switch connected in series with the busbar is disconnected and the first type switch is triggered to close, so that a first discharge loop formed by the capacitor, the first resistor and the first type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor; After the isolating switch is disconnected for a preset time period, determining whether the voltage of the capacitor is lower than a safe voltage; If not, the second type switch is controlled to be turned on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor.

14. The discharge control method according to claim 10, characterized in that: The switch component includes a second type switch, the inverter circuit is at least a part of the circuit in the inverter, and the discharge demand signal includes a signal indicating whether the inverter is open; When it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close includes: In the case where it is determined that the inverter is opened based on the discharge demand signal, determining whether the voltage of the capacitor is lower than a safety voltage; If not, the second type switch is controlled to be turned on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor.

15. The discharge control method according to claim 10, characterized in that: The switch component includes a second type switch, the discharge requirement signal includes a signal indicating whether the traction control circuit has leakage; when it is determined based on the discharge requirement signal that the capacitor needs to be discharged, controlling the switch component to close includes: In the case where it is determined that the traction control circuit is leaking based on the discharge demand signal, determining whether the voltage of the capacitor is lower than a safe voltage; If not, the second type switch is controlled to be turned on, so that a second discharge loop formed by the capacitor, the first resistor and the second type switch is turned on, so as to discharge the voltage of the capacitor through the first resistor.

16. The discharge control method according to claim 11, characterized in that: The inverter circuit further includes a second resistor connected in parallel with the capacitor, the resistance of the second resistor being greater than the resistance of the first resistor, and the discharge demand signal includes an indication of whether power supply to the traction control circuit through an external power supply has been stopped; The discharge control method further includes: When it is determined based on the discharge demand signal that the external power supply to the traction control circuit has stopped, the third discharge loop formed by the second resistor and the capacitor is turned on, and the voltage of the capacitor is discharged through the second resistor.

17. The discharge control method according to any one of claims 11 to 16, characterized in that: The traction control circuit includes at least two inverter circuits, and the at least two inverter circuits include a first inverter circuit and a second inverter circuit; when it is determined based on the discharge demand signal that the capacitor needs to be discharged, controlling the switch component to close includes: When it is determined based on the discharge demand signal that the capacitor in the first inverter circuit needs to be discharged, at least the switch component in the second inverter circuit is controlled to be closed, so that a discharge loop formed by the capacitor in the first inverter circuit, the first resistor in the second inverter circuit, and the switch component in the second inverter circuit is turned on, so as to discharge the voltage of the capacitor in the first inverter circuit through the first resistor in the second inverter circuit; When it is determined based on the discharge demand signal that the capacitor in the second inverter circuit needs to be discharged, at least the switch component in the first inverter circuit is controlled to be closed, so that the discharge loop formed by the capacitor in the second inverter circuit, the first resistor in the first inverter circuit and the switch component in the first inverter circuit is turned on, so as to discharge the voltage of the capacitor in the second inverter circuit through the first resistor in the first inverter circuit.

18. An inverter, characterized in that: The inverter includes an inverter circuit, which is connected to a bus bar and is used to convert and output an electrical signal from the bus bar to tow the vehicle; The inverter circuit comprises a capacitor, a first resistor and a switch component, wherein the capacitor is connected in series with the busbar; the first resistor is connected in series with the switch component and connected in parallel with the capacitor, and the first resistor is used to discharge when the voltage in the inverter circuit is greater than a preset threshold; When the capacitor needs to be discharged, the switch component is closed, and a discharge loop formed by the capacitor, the first resistor and the switch component is turned on to discharge the voltage of the capacitor through the first resistor.

19. A high-voltage box, characterized in that: The high voltage box comprises the traction control circuit according to any one of claims 1-9.

20. A vehicle, characterized in that: The vehicle includes the traction control circuit described in any one of claims 1-9, or the vehicle is used to implement the steps of the discharge control method described in any one of claims 10-17, or the vehicle includes the inverter described in claim 18, or the vehicle includes the high-voltage box of claim 19.

21. An electronic device, characterized in that: The method comprises a memory and a processor, wherein the memory stores a computer program, and wherein the processor implements the steps of the method described in any one of claims 10 to 17 when executing the computer program.

22. A computer-readable storage medium, characterized in that: A computer program is stored thereon, and when the computer program is executed by a processor, the steps of the method described in any one of claims 10 to 17 are implemented.

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