Suspension controller discharge circuit and suspension control system

Abstract

This application relates to a discharge circuit of a suspension controller and a suspension control system. The circuit includes an input filtering module, a discharge control module, and a discharge module. The input end of the input filtering module is used to connect to the system power input circuit. The output end of the input filtering module is connected to the input end of the discharge control module. The output end of the discharge control module is connected to the control end of the discharge module and is used to connect to the suspension controller control circuit. The input end of the discharge module is used to connect to the system power input circuit, and the output end of the discharge module is grounded. The input filtering module is used to supply power to the discharge control module from the system power input circuit during the suspension power-on stage of the suspension controller control circuit. The discharge module remains closed during the suspension power-on stage of the suspension controller control circuit. The discharge control module is used to control the discharge module to discharge the bus voltage during the floating-off power-off stage of the suspension controller control circuit. The purpose of significantly improving the discharge performance is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of electronic circuits, and relates to a discharge circuit for a suspension controller and a suspension control system. Background Art

[0002] When designing the system of a suspension controller, since the output load is a suspension electromagnet, which is a typical inductive load, a large-capacity filter capacitor is configured on the DC bus side of all suspension controllers. Therefore, to meet the safety requirements, the voltage of the filter capacitor configured on the DC bus side of the suspension controller needs to be discharged to DC60V or below within a certain period after power-off. For this, the traditional means of discharging the bus voltage is to directly connect a discharge resistor across the bus or to directly discharge it by means of a normally closed relay control. However, in the process of implementing the present invention, the inventors found that the foregoing traditional means of discharging the bus voltage has the technical problem of low discharge performance. Summary of the Invention

[0003] In view of the problems existing in the above traditional method, the present invention provides a discharge circuit for a suspension controller with high discharge performance and a suspension control system.

[0004] To achieve the above object, the embodiments of the present invention adopt the following technical solutions:

[0005] On the one hand, a discharge circuit for a suspension controller is provided, which includes an input filter module, a discharge control module, and a discharge module;

[0006] The input end of the input filter module is used to connect to the system power input circuit, the output end of the input filter module is connected to the input end of the discharge control module, the output end of the discharge control module is connected to the control end of the discharge module and is used to connect to the suspension controller control circuit, the input end of the discharge module is used to connect to the system power input circuit, and the output end of the discharge module is grounded;

[0007] The input filter module is used to supply power to the discharge control module from the system power input circuit during the suspension power-on stage of the suspension controller control circuit. The discharge module remains closed during the suspension power-on stage of the suspension controller control circuit. The discharge control module is used to control the discharge module to discharge the bus voltage during the suspension power-off stage of the suspension controller control circuit.

[0008] In one embodiment, the discharge control module includes a flyback power supply unit, a low-pass filter unit, and an output voltage feedback loop;

[0009] The output end of the input filter module is connected to the input end of the flyback power supply unit, the output end of the flyback power supply unit is connected to the input end of the low-pass filter unit, and the feedback input end of the flyback power supply unit is connected to the output end of the output voltage feedback loop;

[0010] The output terminals of the low-pass filter unit are respectively connected to the input terminal of the output voltage feedback loop and the control terminal of the discharge module, and the output terminal of the low-pass filter unit is also used to connect to the suspension controller control circuit;

[0011] During the power-on stage of the suspension controller control circuit, the flyback power supply unit is powered by the input filter module, and the low-pass filter unit outputs a control voltage to the suspension controller control circuit;

[0012] During the power-off stage of the suspension controller control circuit, the flyback power supply unit operates and continues to output a control voltage to the low-pass filter unit, and the low-pass filter unit outputs a control voltage to the discharge module until the input voltage of the flyback power supply unit is lower than the operating voltage of the flyback power supply unit.

[0013] In one embodiment, the flyback power supply unit includes a flyback power supply chip U1 and a filter capacitor C1, the output voltage feedback loop includes a loop resistor RF1, a loop resistor RF2, a loop capacitor C2 and a unidirectional conduction diode D2; the low-pass filter unit includes a filter inductor L1, a filter capacitor C3 and a freewheeling diode D3;

[0014] The 5th and 8th pins of the flyback power supply chip U1 are respectively connected to the output terminal of the input filter module, the 4th pin of the flyback power supply chip U1 is connected to one end of the filter capacitor C1, and the other end of the filter capacitor C1 is respectively connected to one end of the loop resistor RF2, one end of the loop capacitor C2, one end of the filter inductor L1, the negative electrode of the freewheeling diode D3, the 1st and 2nd pins of the flyback power supply chip U1. The other end of the loop resistor RF2 is respectively connected to one end of the loop resistor RF1 and the 3rd pin of the flyback power supply chip U1. The other end of the loop resistor RF1 is respectively connected to the other end of the loop capacitor C2 and the negative electrode of the unidirectional conduction diode D2. The positive electrode of the unidirectional conduction diode D2 is respectively connected to the other end of the filter inductor L1 and one end of the filter capacitor C3. The other end of the filter capacitor C3 is grounded, and the positive electrode of the freewheeling diode D3 is grounded;

[0015] One end of the filter capacitor C3 is also used to connect to the control terminal of the discharge module through the normally closed contact of the relay K1 in the suspension controller control circuit, or to access the suspension controller control circuit through the normally open contact of the relay K1.

[0016] In one embodiment, the discharge control module includes a flyback power supply unit, a low-pass filter unit and an output voltage feedback loop;

[0017] The output terminal of the input filtering module is connected to the input terminal of the flyback power supply unit, the output terminal of the flyback power supply unit is connected to the input terminal of the low-pass filtering unit, the feedback input terminal of the flyback power supply unit is connected to the output terminal of the output voltage feedback loop, and the feedback input terminal of the flyback power supply unit is also used to connect to the suspension controller control circuit; the output terminal of the low-pass filtering unit is respectively connected to the input terminal of the output voltage feedback loop and the control terminal of the discharge module;

[0018] During the suspension power-on stage of the suspension controller control circuit, the flyback power supply unit is powered by the input filtering module, and the flyback power supply unit remains off under the control voltage provided by the suspension controller control circuit;

[0019] During the floating-off power-off stage of the suspension controller control circuit, the control power supply voltage provided by the suspension controller control circuit is lost, starts to work and outputs a control voltage to the discharge module through the low-pass filtering unit until the input terminal voltage of the flyback power supply unit is lower than the operating voltage of the flyback power supply unit.

[0020] In one embodiment, the flyback power supply unit includes a flyback power supply chip U1 and a filtering capacitor C1, the output voltage feedback loop includes a loop resistor RF1, a loop resistor RF2, a loop capacitor C2 and a unidirectional conduction diode D2; the low-pass filtering unit includes a filtering inductor L1, a filtering capacitor C3 and a freewheeling diode D3;

[0021] Pin 5 and pin 8 of the flyback power supply chip U1 are respectively connected to the output terminal of the input filtering module, pin 4 of the flyback power supply chip U1 is connected to one end of the filtering capacitor C1, and the other end of the filtering capacitor C1 is respectively connected to one end of the loop resistor RF2, one end of the loop capacitor C2, one end of the filtering inductor L1, the cathode of the freewheeling diode D3, pin 1 and pin 2 of the flyback power supply chip U1. The other end of the loop resistor RF2 is respectively connected to one end of the loop resistor RF1 and pin 3 of the flyback power supply chip U1. The other end of the loop resistor RF1 is respectively connected to the other end of the loop capacitor C2 and the cathode of the unidirectional conduction diode D2. The anode of the unidirectional conduction diode D2 is respectively connected to the other end of the filtering inductor L1, one end of the filtering capacitor C3 and the control terminal of the discharge module. The other end of the filtering capacitor C3 is grounded, and the anode of the freewheeling diode D3 is grounded;

[0022] The other end of the loop capacitor C2 is also used to connect to the control power supply of the suspension controller control circuit, and one end of the loop capacitor C2 is also used to connect to the control power supply ground of the suspension controller control circuit.

[0023] In one embodiment, the discharge circuit of the above-mentioned suspension controller further includes a current-limiting resistor R3 and a one-way conduction diode D4. One end of the current-limiting resistor R3 is connected to the other end of the loop capacitor C2, the other end of the current-limiting resistor R3 is connected to the negative electrode of the one-way conduction diode D4, and the positive electrode of the one-way conduction diode D4 is used to connect the control power supply of the suspension controller control circuit.

[0024] In one embodiment, the input filter module includes a one-way conduction diode D1 and a polarized capacitor EB1. The positive electrode of the one-way conduction diode D1 is used to connect the system power input circuit. The negative electrode of the one-way conduction diode D1 is respectively connected to the input end of the discharge control module and the positive electrode of the polarized capacitor EB1, and the negative electrode of the polarized capacitor EB1 is grounded.

[0025] In one embodiment, the discharge module includes a relay K2 and a resistor R2. One end of the coil of the relay K2 is connected to the output end of the discharge control module, the other end of the coil of the relay K2 is grounded. Among a pair of normally open contacts of the relay K2, one contact is used to connect the system power input circuit, and the other contact is connected to one end of the resistor R2, and the other end of the resistor R2 is grounded.

[0026] On the other hand, a suspension control system is also provided, which includes a system power input circuit, a suspension controller control circuit, and the above-mentioned suspension controller discharge circuit. The system power input circuit is used to connect the system input power supply.

[0027] In one embodiment, the system power input circuit includes a positive connector VIN+, a negative connector VIN-, a system main contactor KM1, a system auxiliary contactor KM2, a current-limiting resistor R1, and a system input filter capacitor E1;

[0028] The positive connector VIN+ is used to connect the positive terminal of the system input power supply, and the negative connector VIN- is used to connect the negative terminal of the system input power supply;

[0029] Among a pair of normally open contacts of the system main contactor KM1, one contact is connected to the positive connector VIN+, and the other contact is respectively connected to one end of the current-limiting resistor R1, the positive electrode of the system input filter capacitor E1, and the input end of the suspension controller discharge circuit. One end of the coil of the system main contactor KM1 is connected to the drive output end of the suspension controller control circuit, and the other end of the coil of the system main contactor KM1 is grounded;

[0030] Among a pair of normally open contacts of the system auxiliary contactor KM2, one contact is connected to the positive connector VIN+, and the other contact is respectively connected to the other end of the current-limiting resistor R1 and the input end of the discharge module in the suspension controller discharge circuit. One end of the coil of the system auxiliary contactor KM2 is connected to the drive output end of the suspension controller control circuit, and the other end of the coil of the system auxiliary contactor KM2 is grounded;

[0031] The negative electrode of the system input filter capacitor E1 is grounded.

[0032] One of the technical solutions in the above technical solutions has the following advantages and beneficial effects:

[0033] In the above floating controller discharge circuit and floating control system, through the circuit structure design of the input filter module, discharge control module and discharge module, during the floating power-on stage of the floating controller control circuit, the input filter module supplies power to the discharge control module from the system power input circuit. At this time, since no control signal is input to the discharge module, it remains in the off state and will not discharge the DC bus voltage of the floating controller control circuit in the system. When the floating controller control circuit enters the falling floating power-off stage, both the system power input circuit and the floating controller control circuit are in the power-off state. Although the external power supply of the discharge control module is also disconnected, the discharge control module can rely on the power of the filter capacitor in the system power input circuit and the input filter module to transfer or maintain the working state, and output a discharge control voltage to the discharge module, so that the discharge module switches to the working state to provide a discharge circuit required for discharging the DC bus voltage, thereby discharging the DC bus voltage. At the end of the discharge, since the discharge control module discharges the power of the filter capacitor in the system power input circuit and the input filter module, the input voltage provided by this power is lower than the working voltage requirement of the discharge control module 14, and it returns to the non-working state. At the same time, the discharge module returns to the off state due to the loss of the discharge control voltage.

[0034] Compared with the traditional method of discharging the bus voltage, instead of directly connecting a discharging resistor in parallel for discharging, an automatic discharge circuit composed of an input filter module, a discharge control module and a discharge module is adopted. The discharge control module automatically controls the discharge module to discharge the bus voltage by using the system input power supply following the working state of the floating controller control circuit, avoiding the problems of high loss, high heat generation and reduced system reliability caused by directly connecting a discharging resistor in parallel, so as to achieve the purpose of significantly improving the discharge performance. Description of the Drawings

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0036] Figure 1 It is a first structural schematic diagram of the floating controller discharge circuit in an embodiment;

[0037] Figure 2It is the second structural schematic diagram of the discharge circuit of the suspension controller in an embodiment;

[0038] Figure 3 It is the third structural schematic diagram of the discharge circuit of the suspension controller in an embodiment;

[0039] Figure 4 It is the fourth structural schematic diagram of the discharge circuit of the suspension controller in an embodiment;

[0040] Figure 5 It is the fifth structural schematic diagram of the discharge circuit of the suspension controller in an embodiment;

[0041] Figure 6 It is the sixth structural schematic diagram of the discharge circuit of the suspension controller in an embodiment;

[0042] Figure 7 It is the structural schematic diagram of the suspension control system in an embodiment;

[0043] Figure 8 It is the structural schematic diagram of the suspension control system in another embodiment. Detailed implementation manners

[0044] In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0046] It should be noted that referring to "embodiment" herein means that a specific feature, structure or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present invention. The display of this phrase at various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments.

[0047] Those skilled in the art can understand that the embodiments described herein can be combined with other embodiments. The term "and / or" used in the specification and claims of the present invention refers to any combination and all possible combinations of one or more of the related listed items, and includes these combinations. The connection between the components of this application can be a direct electrical connection, an indirect electrical connection through a middleware, or a connection implemented by other transmission lines.

[0048] For the startup of the control power supply itself, the control of power supply requirements, or other similar operating conditions, corresponding control power supply can be designed to meet the power-on startup and power supply requirements of the internal control circuit.

[0049] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings in the embodiments of the present invention.

[0050] Please refer to Figure 1 , in one embodiment, the present application provides a suspension controller discharge circuit 100, including an input filter module 12, a discharge control module 14, and a discharge module 16. The input end of the input filter module 12 is used to connect to the system power input circuit 201, and the output end of the input filter module 12 is connected to the input end of the discharge control module 14. The output end of the discharge control module 14 is connected to the control end of the discharge module 16 and is used to connect to the suspension controller control circuit 202. The input end of the discharge module 16 is used to connect to the system power input circuit 201, and the output end of the discharge module 16 is grounded. The input filter module 12 is used to supply power to the discharge control module 14 from the system power input circuit 201 during the suspension power-on stage of the suspension controller control circuit 202, and the discharge module 16 remains closed during the suspension power-on stage of the suspension controller control circuit 202. The discharge control module 14 is used to control the discharge module 16 to discharge the bus voltage during the floating-off power-off stage of the suspension controller control circuit 202.

[0051] It can be understood that the system power input circuit 201 refers to the existing input circuit part that accesses the suspension controller input bus voltage (system input power supply), is connected to the drive port of the suspension controller control circuit 202, and includes a large-capacity filter capacitor (denoted as E1) configured by the suspension controller on its DC bus side. The input filter module 12 is a filter circuit module that filters the input voltage introduced by the system power input circuit 201 and then sends it to the discharge control module 14 to ensure the reliable power supply requirements of the discharge control module 14. The discharge control module 14 is a control circuit used to realize the control of whether the discharge module 16 discharges. It uses the power supply of the system power input circuit 201 and the input filter module 12 to support its own operation to complete the required discharge control function. The discharge module 16 is a circuit module that is connected to the system power input circuit 201 and provides a non-parallel discharge circuit for the large-capacity filter capacitor E1 configured on the DC bus side of the system power input circuit 201, such as providing a series discharge circuit, to avoid the problems brought by parallel-connected discharge resistors: large losses, significant reduction in system efficiency, high heat generation resulting in an increase in the overall temperature of the suspension controller and a decrease in system reliability, and the need to configure a large-capacity radiator, increasing system weight and cost.

[0052] When a normally closed relay is used in traditional bus (capacitance) voltage discharge means, since the input bus voltage of the suspension controller ranges from DC200V to DC1000V, a suitable DC normally closed relay cannot be found on the current market. Therefore, to meet the voltage discharge requirement after the suspension controller is powered off and considering its efficiency, function, and reliability comprehensively, the above-mentioned suspension controller discharge circuit 100 is designed in this embodiment: when the suspension controller is powered on, the suspension controller control circuit 202 starts. When a suspension command is received, the suspension controller control circuit 202 enters the power-on stage of operation. The voltage of the system input power supply connected by the system power input circuit 201 can be filtered by the input filter module 12 and then input to the discharge control module 14 to supply power to this module. Due to limitations such as insufficient input voltage at its own input end, failure to meet the working point requirements, or inability of the output voltage to reach the discharge module 16 in this stage, the discharge module 16 remains closed during the suspension power-on stage of the suspension controller control circuit 202, and does not connect to the system power input circuit 201, thus not providing a discharge loop.

[0053] When the system receives the floating-down command and is powered off, at this time, the suspension controller and its control circuit are both powered off, and the system power input circuit 201 is also powered off, causing the input filter module 12 to disconnect the direct power supply to the discharge control module 14 from the system input power supply. Since the discharge control module 14 will start working or maintain the working state under the power supply of the charged capacitors in the system power input circuit 201 and the input filter module 12, an effective control voltage is generated and output to the discharge module 16, causing the discharge module 16 to switch to the on state during the floating-down power-off stage of the suspension controller control circuit 202, connect to the system power input circuit 201 to provide a discharge loop, and discharge the bus voltage. As the charged capacitors in the system power input circuit 201 and the input filter module 12 discharge, when their charge is insufficient to support the working voltage requirement of the discharge control module 14, the discharge control module 14 stops working, and the discharge module 16 also returns to the off state, and the discharge ends.

[0054] The above-mentioned suspension controller discharge circuit 100, through the circuit structure design of the input filter module 12, the discharge control module 14, and the discharge module 16, during the suspension power-on stage of the suspension controller control circuit 202, the input filter module 12 supplies power to the discharge control module 14 from the system power input circuit 201. At this time, since no control signal is input to the discharge module 16, it remains in the off state and will not discharge the DC bus voltage of the suspension controller control circuit 202 in the system. When the suspension controller control circuit 202 enters the floating-off power-off stage, both the system power input circuit 201 and the suspension controller control circuit 202 are in the power-off state. Although the external direct power supply of the discharge control module 14 is also disconnected, the discharge control module 14 can rely on the power of the filter capacitors in the system power input circuit 201 and the input filter module 12 to switch to or maintain the working state, and output a discharge control voltage to the discharge module 16, so that the discharge module 16 switches to the working state to provide a discharge circuit required for discharging the DC bus voltage, thereby discharging the DC bus voltage. At the end of the discharge, since the discharge control module 14 discharges the power of the filter capacitors in the system power input circuit 201 and the input filter module 12, the input voltage provided by this power is lower than the working voltage requirement of the discharge control module 14, and it returns to the non-working state. At the same time, the discharge module 16 returns to the off state due to the loss of the discharge control voltage.

[0055] In the traditional means of discharging the bus voltage, for the scheme of connecting a discharge resistor in parallel, when the system power supply voltage is DC440V and the DC bus filter capacitor is configured as 0.01F, the time required to discharge to below DC60V should not be greater than 1 minute. Then the selected discharge resistor should not be greater than 3KΩ, and the loss of the discharge resistor during normal operation is about 64.5W. Moreover, due to the scheme of connecting a discharge resistor in parallel, the discharge resistor works in real time throughout the operation of the system, so its loss will always occur. For the method controlled by a normally closed relay, there is no normally closed relay suitable in the range of DC300 - 1000V in the current market.

[0056] Compared with the traditional means of discharging the bus voltage, the above scheme of the present application no longer uses the method of directly connecting a discharge resistor in parallel for discharging, but adopts an automatic discharge circuit composed of the input filter module 12, the discharge control module 14, and the discharge module 16. The discharge control module 14 automatically controls the discharge module 16 to discharge the bus voltage by following the working state of the suspension controller control circuit 202 using the system input power. The discharge is precisely controllable. And during the normal suspension stage of the system, the discharge circuit exits the working state, avoiding the problems of high loss, high heat generation, and reduced system reliability caused by directly connecting a discharge resistor in parallel, and also eliminating the need for a suitable normally closed relay, thereby achieving the purpose of significantly improving the discharge performance.

[0057] In one embodiment, asFigure 2 As shown, the discharge control module 14 includes a flyback power supply unit 142, a low-pass filter unit 144, and an output voltage feedback loop 146. The output end of the input filter module 12 is connected to the input end of the flyback power supply unit 142. The output end of the flyback power supply unit 142 is connected to the input end of the low-pass filter unit 144. The feedback input end of the flyback power supply unit 142 is connected to the output end of the output voltage feedback loop 146. The output end of the low-pass filter unit 144 is respectively connected to the input end of the output voltage feedback loop 146 and the control end of the discharge module 16. The output end of the low-pass filter unit 144 is also used to connect to the suspension controller control circuit 202. During the suspension power-on stage of the suspension controller control circuit 202, the flyback power supply unit 142 is powered by the input filter module 12, and the low-pass filter unit 144 outputs a control voltage to the suspension controller control circuit 202. During the floating-off power-off stage of the suspension controller control circuit 202, the flyback power supply unit 142 works and keeps outputting a control voltage to the low-pass filter unit 144, and the low-pass filter unit 144 outputs a control voltage to the discharge module 16 until the voltage at the input end of the flyback power supply unit 142 is lower than the working voltage of the flyback power supply unit 142.

[0058] It can be understood that the flyback power supply unit 142 is an output control unit with a flyback power supply as the core, and can provide the required discharge control voltage VCC for the discharge module 16 during the floating-off power-off stage of the system after starting to work. The low-pass filter unit 144 is used to filter and output the output voltage VCC of the flyback power supply unit 142, and can be constructed by various types of filter inductors and capacitor components in the art, as long as it can provide a suitable low-pass filter in the circuit. The output voltage feedback loop 146 is used to feedback the output voltage VCC to the flyback power supply unit 142, so that the flyback power supply unit 142 decides whether to work according to the change of the output voltage VCC. The output voltage feedback loop 146 can be built using common resistor and capacitor components according to the feedback voltage input requirements of the flyback power supply core, as long as it can feedback the output voltage VCC to the feedback voltage input of the flyback power supply core.

[0059] Specifically, when the suspension controller is powered on, the suspension controller control circuit 202 starts. When receiving a suspension command, the suspension controller control circuit 202 enters the power-on stage to work. The voltage of the system input power supply connected by the system power input circuit 201 can be voltage-filtered by the input filter module 12 and then input to the flyback power supply unit 142 to supply power to this unit. Due to limitations such as the insufficient input voltage of the flyback power supply unit 142 itself, the failure to meet the working point requirements, or the inability of the output control voltage to reach the discharge module 16 during this stage, the discharge module 16 remains in the off state during the suspension power-on stage of the suspension controller control circuit 202.

[0060] At this time, since the control voltage output by the low-pass filter unit 144 (i.e., the discharge control voltage VCC) is connected to the suspension controller control circuit 202, the suspension controller control circuit 202 can also detect the discharge control voltage VCC of the discharge loop to determine whether the power supply of the discharge loop is normal, so as to know whether the working state of the suspension controller discharge circuit 100 is normal. For example, when it is detected that the discharge control voltage VCC is lower than a certain range value of the rated output voltage value VCC, the suspension controller control circuit 202 generates a fault alarm signal for output, which is sent up to the train diagnosis network system, and the system alarms for the discharge circuit accordingly, prompting that maintenance is required after the train enters the station.

[0061] When the system receives the floating-down command and is powered off, at this time, the suspension controller and its control circuit are both in a power-off state, and the system power input circuit 201 is also powered off. Since the flyback power supply unit 142 will start working or maintain the working state under the power supply of the charged amount of the filter capacitors in the system power input circuit 201 and the input filter module 12, an effective discharge control voltage VCC is generated and output to the discharge module 16, so that the flyback power supply unit 142 switches to the on state during the floating-down power-off stage of the suspension controller control circuit 202. The output control voltage forms an effective discharge control voltage VCC after being filtered by the low-pass filter unit 144 and is given to the discharge module 16, so that the discharge module 16 connects the system power input circuit 201 to provide a discharge loop and discharge the bus voltage. As the charged amount of the filter capacitors in the system power input circuit 201 and the input filter module 12 is discharged, and the power is insufficient to support the working voltage requirement of the flyback power supply unit 142, that is, the input voltage of the flyback power supply unit 142 is lower than the working voltage of the flyback power supply unit 142, the flyback power supply unit 142 stops working, and the discharge module 16 also returns to the closed state, and the discharge ends.

[0062] Through the design of the above discharge control module 14, automatic discharge control can be efficiently and reliably realized with a simple circuit architecture, and the working state of the suspension controller discharge circuit 100 can be further detected, thereby further improving the circuit performance.

[0063] In one embodiment, as Figure 3As shown, the flyback power supply unit 142 includes a flyback power supply chip U1 and a filter capacitor C1. The output voltage feedback loop 146 includes a loop resistor RF1, a loop resistor RF2, a loop capacitor C2, and a unidirectional conduction diode D2. The low-pass filter unit 144 includes a filter inductor L1, a filter capacitor C3, and a freewheeling diode D3. The 5th pin (i.e., HVIN, the high-voltage input pin) and the 8th pin (i.e., DRAIN, the drain pin of the internal Mos transistor of the chip) of the flyback power supply chip U1 are respectively connected to the output end of the input filter module 12, and the 4th pin (i.e., VDD power supply pin) of the flyback power supply chip U1 is connected to one end of the filter capacitor C1. The other end of the filter capacitor C1 is respectively connected to one end of the loop resistor RF2, one end of the loop capacitor C2, one end of the filter inductor L1, the cathode of the freewheeling diode D3, the 1st pin and the 2nd pin (i.e., GND ground pin) of the flyback power supply chip U1. The 6th pin NC of the flyback power supply chip U1 is a non-functional pin and remains floating.

[0064] The other end of the loop resistor RF2 is respectively connected to one end of the loop resistor RF1 and the 3rd pin (i.e., FB, the feedback pin) of the flyback power supply chip U1. The other end of the loop resistor RF1 is respectively connected to the other end of the loop capacitor C2 and the cathode of the unidirectional conduction diode D2. The anode of the unidirectional conduction diode D2 is respectively connected to the other end of the filter inductor L1 and one end of the filter capacitor C3. The other end of the filter capacitor C3 is grounded, and the anode of the freewheeling diode D3 is grounded. One end of the filter capacitor C3 is also used to connect the control end of the discharge module 16 through the normally closed contact of the relay K1 in the suspension controller control circuit 202, or to access the suspension controller control circuit 202 through the normally open contact of the relay K1.

[0065] Specifically, in this embodiment, the discharge control module 14 with the above specific circuit structure is designed, and the flyback power supply chip U1 is an existing flyback power supply chip integrating switching devices. The loop resistor RF1, the loop resistor RF2, the loop capacitor C2, and the unidirectional conduction diode D2 constitute the main body of the output voltage feedback loop 146. The output voltage feedback loop 146 extracts a feedback voltage signal from the discharge control voltage VCC and sends it to the feedback input terminal (3rd pin) of the flyback power supply chip U1. The filter capacitor C1 is the working power filter capacitor of the flyback power supply chip U1. The filter inductor L1 and the filter capacitor C3 constitute a low-pass filter to filter the output of the flyback power supply chip U1, and the freewheeling diode D3 provides freewheeling for the filter inductor L1.

[0066] When the suspension controller is powered on, the suspension controller control circuit 202 is started. When receiving a suspension command, the control circuit will first connect the system power input circuit 201 to access the system input power supply. Then, it charges the internal filter capacitor E1 through the system power input circuit 201. When it detects that the voltage of the filter capacitor E1 is charged to the input voltage value, the suspension controller normally operates to output a suspension current.

[0067] During the charging process of the filter capacitor E1, when the voltage across the filter capacitor E1 reaches a certain value (such as the operating voltage of the flyback power supply chip U1), the flyback power supply chip U1 starts and outputs a discharge control voltage VCC. The discharge control voltage VCC is connected to the floating controller control circuit 202 through the normally open contacts of the relay K1 in the floating controller control circuit 202 (i.e., K1:3 and K1:4). At this time, since the normally open contacts of the K1 relay are closed, the floating controller control circuit 202 can judge the working state of the discharge circuit by detecting the VCC voltage value. When the detected VCC is lower than the rated output voltage value VCC by a certain range, the system gives an alarm for the discharge circuit fault.

[0068] When the system receives the floating-down command and floats down and powers off normally, at this time, the floating controller and its control circuit are both in a power-off state. Due to the power-off, the system power input circuit 201 and the relay K1 are also both in an open state. There is no discharge loop outside the filter capacitor E1, and the terminal voltage across the filter capacitor E1 will not change. The flyback power supply chip U1, which is powered by the filter capacitor E1 through the input filter module 12, will continue to work and maintain a stable output of the discharge control voltage VCC. Since the relay K1 is powered off and open, its normally closed contacts (i.e., K1:3 and K1:5) remain closed, that is, the discharge control voltage VCC is output to the control end of the discharge module 16 through the normally closed contacts of the relay K1 to control the normal operation of the discharge module 16 to provide a discharge loop until the terminal voltage value of the filter capacitor E1 is lower than the input power supply voltage range (i.e., the operating voltage) of the flyback power supply chip U1 and then stops working, the discharge control voltage VCC loses voltage, the discharge module 16 disconnects and ends the operation, and the discharge ends.

[0069] Through the above specific circuit design, a high-performance discharge effect of the system is achieved efficiently and reliably with a simple circuit.

[0070] In one embodiment, such as Figure 4As shown in the figure, the discharge control module 14 includes a flyback power supply unit 142, a low-pass filter unit 144, and an output voltage feedback loop 146. The output end of the input filter module 12 is connected to the input end of the flyback power supply unit 142. The output end of the flyback power supply unit 142 is connected to the input end of the low-pass filter unit 144. The feedback input end of the flyback power supply unit 142 is connected to the output end of the output voltage feedback loop 146. The feedback input end of the flyback power supply unit 142 is also used to connect to the suspension controller control circuit 202. The output end of the low-pass filter unit 144 is respectively connected to the input end of the output voltage feedback loop 146 and the control end of the discharge module 16. During the power-on stage of the suspension controller control circuit 202, the flyback power supply unit 142 is powered by the input filter module 12, and the flyback power supply unit 142 remains off under the control voltage provided by the suspension controller control circuit 202. During the power-off stage of the suspension controller control circuit 202, the control power voltage provided by the suspension controller control circuit 202 is de-energized, and the flyback power supply unit 142 starts to work and outputs a control voltage to the discharge module 16 through the low-pass filter unit 144 until the input voltage of the flyback power supply unit 142 is lower than the operating voltage of the flyback power supply unit 142.

[0071] It can be understood that in this embodiment, a circuit structure of the discharge control module 14 with another working mechanism is provided. Specifically, when the suspension controller is powered on, the suspension controller control circuit 202 starts, the control power supply (AVCC\AGND) of the suspension controller control circuit 202 works normally, and the control power supply voltage AVCC provided by the suspension controller control circuit 202 is sent to the feedback input end of the flyback power supply unit 142 through the output voltage feedback loop 146. By setting the control power supply voltage AVCC to be higher than the feedback voltage value of the flyback power supply unit 142 within a certain range, the flyback power supply unit 142 can be made not to start working because the control power supply voltage AVCC input to the feedback input end at this time is higher than its feedback voltage value.

[0072] When receiving the suspension command, the suspension controller control circuit 202 enters the power-on stage of operation. The suspension controller works normally and outputs a suspension current. The voltage of the system input power supply connected to the system power input circuit 201 can be voltage-filtered by the input filter module 12 and then input to the flyback power supply unit 142 to supply power to this unit. Since the flyback power supply unit 142 does not start working because the control power supply voltage AVCC input to the feedback input end at this time is higher than its feedback voltage value during this stage, the discharge module 16 remains in the off state during the power-on stage of the suspension controller control circuit 202.

[0073] When the system receives the floating-down command and loses power, the suspension controller and its control circuit are both de-energized. The system power input circuit 201 also loses power. There is no discharge path outside the filter capacitor E1 inside the system power input circuit 201. Therefore, the terminal voltage of the filter capacitor E1 will not change. However, at this time, the control power supply voltage AVCC loses voltage and gradually decreases. When the feedback input terminal of the flyback power supply unit 142 detects that the input control power supply voltage AVCC is lower than the feedback voltage value, it will start to work and maintain a stable output of the discharge control voltage VCC. The discharge control voltage VCC is sent to the control terminal of the discharge module 16 after passing through the low-pass filter unit 144, so that the discharge module 16 connects to the system power input circuit 201 to provide a discharge path for the filter capacitor E1 and discharge the bus voltage. As the charge of the filter capacitor E1 is discharged, when its charge is insufficient to support the working voltage requirement of the flyback power supply unit 142, that is, when the input voltage of the flyback power supply unit 142 is lower than the working voltage of the flyback power supply unit 142, the flyback power supply unit 142 stops working, and the discharge module 16 also returns to the off state, and the discharge ends.

[0074] Through the design of the above discharge control module 14, automatic discharge control can be efficiently and reliably realized with a simple circuit architecture. Since the discharge control module 14 is in the off state during the normal suspension stage of the system, the no-load loss of the circuit can be further reduced.

[0075] In one embodiment, as Figure 5 shown, the flyback power supply unit 142 includes a flyback power supply chip U1 and a filter capacitor C1. The output voltage feedback loop 146 includes a loop resistor RF1, a loop resistor RF2, a loop capacitor C2, and a unidirectional conduction diode D2. The low-pass filter unit 144 includes a filter inductor L1, a filter capacitor C3, and a freewheeling diode D3. The 5th and 8th pins of the flyback power supply chip U1 are respectively connected to the output terminal of the input filter module 12, and the 4th pin of the flyback power supply chip U1 is connected to one end of the filter capacitor C1. The other end of the filter capacitor C1 is respectively connected to one end of the loop resistor RF2, one end of the loop capacitor C2, one end of the filter inductor L1, the cathode of the freewheeling diode D3, the 1st and 2nd pins of the flyback power supply chip U1. The other end of the loop resistor RF2 is respectively connected to one end of the loop resistor RF1 and the 3rd pin of the flyback power supply chip U1. The other end of the loop resistor RF1 is respectively connected to the other end of the loop capacitor C2 and the cathode of the unidirectional conduction diode D2. The anode of the unidirectional conduction diode D2 is respectively connected to the other end of the filter inductor L1, one end of the filter capacitor C3, and the control terminal of the discharge module 16. The other end of the filter capacitor C3 is grounded, and the anode of the freewheeling diode D3 is grounded. The other end of the loop capacitor C2 is also used to connect the control power supply AVCC of the suspension controller control circuit 202, and one end of the loop capacitor C2 is also used to connect the control power supply ground AGND of the suspension controller control circuit 202.

[0076] Specifically, in this embodiment, the discharge control module 14 of the above-mentioned another working mechanism is designed, and the flyback power supply chip U1 integrates the existing flyback power supply chip of the switching device. The loop resistors RF1, RF2, the loop capacitor C2, and the unidirectional conduction diode D2 form the main body of the output voltage feedback loop 146. The output voltage feedback loop 146 takes out the feedback voltage signal from the discharge control voltage VCC and sends it to the feedback input terminal (pin 3) of the flyback power supply chip U1. During the period when the flyback power supply chip U1 does not start working, the control voltage AVCC provided by the floating controller control circuit 202 is sent to the feedback input terminal of the flyback power supply chip U1 through the loop resistor RF1. The filter capacitor C1 is the working power filter capacitor of the flyback power supply chip U1. The filter inductor L1 and the filter capacitor C3 form a low-pass filter to filter the output of the flyback power supply chip U1, and the freewheeling diode D3 provides freewheeling for the filter inductor L1.

[0077] When the floating controller is powered on, the floating controller control circuit 202 starts, and the control power supply (AVCC\AGND) of the floating controller control circuit 202 works normally. The control power supply voltage AVCC will be output to the feedback pin 3 of the flyback power supply chip U1, and the control power supply voltage AVCC is set to be higher than the feedback voltage value of the flyback power supply chip U1 by a certain range. Therefore, since the control power supply voltage AVCC is higher than the feedback voltage value of the flyback power supply chip U1 at this time, the flyback power supply chip U1 will not start to work normally. When receiving the floating command, the floating controller control circuit 202 will first close the system power input circuit 201 to charge the filter capacitor E1. When it is detected that the voltage of the filter capacitor E1 is charged to the input voltage value (VIN), the floating controller works normally and outputs the floating current. During the charging process of the filter capacitor E1, when the terminal voltage of the filter capacitor E1 reaches the start-up voltage of the flyback power supply chip U1, since the control power supply voltage AVCC is higher than the feedback voltage value of the flyback power supply chip U1 at this time, the flyback power supply chip U1 will not start to work at this time.

[0078] When the system receives the landing command and is powered off, at this time, the floating controller and its control circuit are both in a power-off state. Due to the power-off, the system power input circuit 201 is also in a power-off state. There is no discharge loop outside the filter capacitor E1, and the terminal voltage of the filter capacitor E1 will not change. However, at this time, the control power supply voltage AVCC loses voltage and gradually decreases. When the feedback input terminal of the flyback power supply chip U1 detects that the control power supply voltage AVCC is lower than its feedback voltage value, it will start to work normally and maintain a stable output of the discharge control voltage VCC. The control end of the discharge module 16 is powered on and works normally, providing a discharge loop for the filter capacitor E1, thereby discharging the bus voltage; until the terminal voltage value of the filter capacitor E1 is lower than the input power supply voltage range of the flyback power supply chip U1, it stops working, the discharge control voltage VCC loses voltage, and the discharge module 16 loses power and shuts down, and the discharge ends.

[0079] Through the above specific circuit design, a high-performance discharge effect of the system is efficiently and reliably achieved with a simple circuit, and there is no no-load loss.

[0080] In one embodiment, as Figure 5 shown, the suspension controller discharge circuit 100 further includes a current-limiting resistor R3 and a one-way conduction diode D4. One end of the current-limiting resistor R3 is connected to the other end of the loop capacitor C2, the other end of the current-limiting resistor R3 is connected to the negative electrode of the one-way conduction diode D4, and the positive electrode of the one-way conduction diode D4 is used to connect the control power supply of the suspension controller control circuit 202.

[0081] Further, in this embodiment, the control voltage AVCC will be output to the feedback pin 3 of the flyback power chip U1 through the current-limiting resistor R3 and the one-way conduction diode D4, so as to ensure the smoothness and one-way transmission of the control voltage AVCC, and improve the working stability and safety of the circuit.

[0082] In one embodiment, as Figure 6 shown, the input filter module 12 includes a one-way conduction diode D1 and a polarized capacitor EB1. The positive electrode of the one-way conduction diode D1 is used to connect the system power input circuit 201, the negative electrode of the one-way conduction diode D1 is respectively connected to the input end of the discharge control module 14 and the positive electrode of the polarized capacitor EB1, and the negative electrode of the polarized capacitor EB1 is grounded.

[0083] Further, in this embodiment, a one-way conduction diode D1 and a polarized capacitor EB1 are used to form the required input filter module 12, so as to achieve reliable input voltage filtering with the simplest circuit structure, reduce the circuit complexity and production cost. It should be noted that in this embodiment, the Figure 3 shown circuit is taken as an example for illustration, and the same understanding applies to the Figure 5 discharge module 16 part in the

[0084] In one embodiment, as Figure 6 shown, the discharge module 16 includes a relay K2 and a resistor R2. One end of the coil of the relay K2 is connected to the output end of the discharge control module 14, the other end of the coil of the relay K2 is grounded, and among a pair of normally open contacts of the relay K2, one contact is used to connect the system power input circuit 201, and the other contact is connected to one end of the resistor R2, and the other end of the resistor R2 is grounded.

[0085] It should be noted that in this embodiment, the Figure 3 shown circuit is taken as an example for illustration, and for the Figure 5The understanding of the discharge module 16 in the circuit shown is the same by analogy. Further, in this embodiment, a relay K2 and a resistor R2 are used to form the required discharge module 16. Since the relay K2 is a DC normally open relay, there are no strict product selection restrictions. The resistor R2 forms a controlled discharge circuit with a non-directly connected discharge resistor, with low loss and very little heat generation. With the simplest circuit structure, it realizes a reliable, efficient and low-loss automatic discharge effect, and also reduces the circuit complexity and production cost.

[0086] In one embodiment, a suspension control system is further provided, including a system power input circuit, a suspension controller control circuit, and the above-mentioned suspension controller discharge circuit 100. The system power input circuit is used to connect the system input power supply.

[0087] It can be understood that the description and definition of the suspension controller discharge circuit 100 in this embodiment can be understood by analogy with the corresponding description and definition in the respective embodiments of the above-mentioned suspension controller discharge circuit 100, and will not be elaborated here. Those skilled in the art can understand that the suspension control system referred to here may further include other structural components in addition to the above-mentioned suspension controller discharge circuit 100, as well as the existing system power input circuit and suspension controller control circuit. Specifically, it can be understood by analogy with the structural composition of various types of suspension control systems in the art, and will not be elaborated one by one in this specification.

[0088] The above-mentioned suspension control system realizes a high-performance system automatic discharge effect by applying the above-mentioned suspension controller discharge circuit 100.

[0089] In one embodiment, as Figure 7 shown and Figure 8As shown, the system power input circuit includes a positive connector VIN+, a negative connector VIN-, a system main contactor KM1, a system auxiliary contactor KM2, a current-limiting resistor R1, and a system input filter capacitor E1. The positive connector VIN+ is used to connect to the positive terminal of the system input power supply, and the negative connector VIN- is used to connect to the negative terminal of the system input power supply. Among a pair of normally open contacts of the system main contactor KM1, one contact is connected to the positive connector VIN+, and the other contact is respectively connected to one end of the current-limiting resistor R1, the positive electrode of the system input filter capacitor E1, and the input terminal of the floating controller discharge circuit. One end of the coil of the system main contactor KM1 is connected to the drive output terminal of the floating controller control circuit 202, and the other end of the coil of the system main contactor KM1 is grounded. Among a pair of normally open contacts of the system auxiliary contactor KM2, one contact is connected to the positive connector VIN+, and the other contact is respectively connected to the other end of the current-limiting resistor R1 and the input terminal of the discharge module in the floating controller discharge circuit 100. One end of the coil of the system auxiliary contactor KM2 is connected to the drive output terminal of the floating controller control circuit 202, and the other end of the coil of the system auxiliary contactor KM2 is grounded. The negative electrode of the system input filter capacitor E1 is grounded.

[0090] Specifically, for Figure 7 the floating control system 200 shown: When the floating controller is powered on, the floating controller control circuit 202 starts. When receiving a floating command, the floating controller control circuit 202 will first close the relay K1 and disconnect the normally closed loop of the relay K1 (disconnect the normally closed contacts K1:3 and K1:5). Then close the system auxiliary contactor KM2, and charge the filter capacitor E1 through the current-limiting loop composed of the system auxiliary contactor KM2 and the current-limiting resistor R1. When it is detected that the voltage of the filter capacitor E1 is charged to the input voltage (VIN) value, close the system main contactor KM1, and the floating controller normally operates to output a floating current. During the charging process of the filter capacitor E1, when the terminal voltage of the filter capacitor E1 reaches a certain value, the flyback power chip U1 starts and outputs a discharge control voltage VCC. The discharge control voltage VCC is connected to the floating controller control circuit 202 through the normally open contacts K1:3 and K1:4 of the relay K1. Since the relay K1 is closed at this time, the floating controller control circuit 202 can judge the working state of the discharge circuit by detecting the value of its VCC voltage. When it is lower than a certain range value of the rated output voltage value VCC, the system gives an alarm for the discharge circuit failure.

[0091] When the system receives the floating-down command and floats down normally and then powers off, at this time, the suspension controller and its control circuit are both in a power-off state. Due to the power-off, the main contactor KM1 of the system, the auxiliary contactor KM2 of the system, and the relay K1 are also all in an open state. There is no external discharge circuit for the terminal voltage of the filter capacitor E1, so the terminal voltage of the filter capacitor E1 will not change. The flyback power supply chip U1, which is powered by the filter capacitor E1 and the filter capacitor EB1, will continue to work and maintain a stable output of VCC. Since the relay K1 is powered off and open, its normally closed contacts K1:3 and K1:5 remain closed, that is, VCC is output to the coil of the relay K2 through the normally closed contacts K1:3 and K1:5 of the relay K1 to control the normal operation of the relay K2. Its normally open contacts K2:1 and K2:2 are closed. At this time, the current-limiting resistor R1, the resistor R2, and the relay K2 form a discharge circuit, and it stops working until the terminal voltage value of the filter capacitor E1 is lower than the input power supply voltage range of the flyback power supply chip U1. The discharge control voltage VCC loses voltage, the relay K2 opens, and the discharge ends.

[0092] For Figure 8 The suspension control system 200 shown: When the suspension controller is powered on, the control circuit 202 of the suspension controller starts. The control power supply (AVCC\AGND) of the control circuit 202 of the suspension controller works normally. The control power supply voltage AVCC will be output to the feedback pin 3 of the flyback power supply chip U1 through the resistor R3 and the unidirectional conduction diode D4. The control power supply voltage AVCC is set to be higher than the feedback voltage value of the flyback power supply chip U1 by a certain range. Therefore, since the control power supply voltage AVCC is higher than the feedback voltage value at this time, the flyback power supply chip U1 will not start to work normally. When receiving the floating command, the control circuit will first close the auxiliary contactor KM2 of the system, and charge the filter capacitor E1 through the current-limiting circuit composed of the auxiliary contactor KM2 of the system and the resistor R1. When it is detected that the voltage of the filter capacitor E1 is charged to the input voltage value, the main contactor KM1 of the system is closed, and the suspension controller works normally to output the suspension current. During the charging process of the filter capacitor E1, when the charging voltage reaches the startup voltage of the flyback power supply chip U1, since the control power supply voltage AVCC is higher than the feedback voltage value of the flyback power supply chip U1 at this time, the flyback power supply chip U1 will not start to work at this time.

[0093] When the system receives the floating-down command and powers off, the suspension controller and its control circuit are both in a power-off state. Due to the power-off, the main contactor KM1 and the auxiliary contactor KM2 of the system are also in an open state. There is no external discharge circuit for the terminal voltage of the filter capacitor E1, so the terminal voltage of the filter capacitor E1 will not change. However, at this time, the control power supply voltage AVCC loses voltage and gradually decreases. When the feedback terminal of the flyback power supply chip U1 detects that the control power supply voltage AVCC is lower than its output voltage (i.e., lower than the feedback voltage value), it will start to work normally and maintain a stable output of the discharge control voltage VCC. The coil of the relay K2 is energized to control the normal operation of the relay K2, and its normally open contacts K2:1 and K2:2 are closed. At this time, the resistor R1, the resistor R2, and the relay K2 form a discharge circuit, and it stops working until the terminal voltage value of the filter capacitor E1 is lower than the input power supply voltage range of the flyback power supply chip U1. The voltage VCC loses voltage, the relay K2 opens, and the discharge ends.

[0094] Through the circuit design of the above suspension control system 200, a flexible high-performance automatic discharge scheme selection is provided, and the applicability is relatively strong.

[0095] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification.

[0096] The above embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several deformations and improvements can still be made, which all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. A discharge circuit for a suspension controller, characterized in that, it includes an input filter module, a discharge control module and a discharge module; The input end of the input filter module is used to connect the system power input circuit, the input end of the discharge module is used to connect the system power input circuit, and the output end of the discharge module is grounded; The input filter module is used to filter the input voltage introduced by the system power input circuit during the floating power-on stage of the suspension controller control circuit. The discharge module remains closed during the floating power-on stage of the suspension controller control circuit. The discharge control module is used to control the discharge module to discharge the bus voltage during the floating power-off stage of the suspension controller control circuit; wherein, the discharge control module includes a flyback power supply unit, a low-pass filter unit and an output voltage feedback loop; The output end of the input filter module is connected to the input end of the flyback power supply unit, the output end of the flyback power supply unit is connected to the input end of the low-pass filter unit, and the feedback input end of the flyback power supply unit is connected to the output end of the output voltage feedback loop; The output end of the low-pass filter unit is respectively connected to the input end of the output voltage feedback loop and the control end of the discharge module, and the output end of the low-pass filter unit is also used to connect the suspension controller control circuit; During the floating power-on stage of the suspension controller control circuit, the flyback power supply unit is powered by the input filter module, and the low-pass filter unit outputs a control voltage to the suspension controller control circuit; During the floating power-off stage of the suspension controller control circuit, the flyback power supply unit works and keeps outputting the control voltage to the low-pass filter unit. The low-pass filter unit outputs the control voltage to the discharge module until the input voltage of the flyback power supply unit is lower than the working voltage of the flyback power supply unit.

2. The discharge circuit for a suspension controller according to claim 1, characterized in that, The flyback power supply unit includes a flyback power supply chip U1 and a filter capacitor C1. The output voltage feedback loop includes a loop resistor RF1, a loop resistor RF2, a loop capacitor C2 and a unidirectional conduction diode D2; the low-pass filter unit includes a filter inductor L1, a filter capacitor C3 and a freewheeling diode D3; Pin 5 and pin 8 of the flyback power supply chip U1 are respectively connected to the output end of the input filter module. Pin 4 of the flyback power supply chip U1 is connected to one end of the filter capacitor C1. The other end of the filter capacitor C1 is respectively connected to one end of the loop resistor RF2, one end of the loop capacitor C2, one end of the filter inductor L1, the cathode of the freewheeling diode D3, pin 1 and pin 2 of the flyback power supply chip U1. The other end of the loop resistor RF2 is respectively connected to one end of the loop resistor RF1 and pin 3 of the flyback power supply chip U1. The other end of the loop resistor RF1 is respectively connected to the other end of the loop capacitor C2 and the cathode of the unidirectional conduction diode D2. The anode of the unidirectional conduction diode D2 is respectively connected to the other end of the filter inductor L1 and one end of the filter capacitor C3. The other end of the filter capacitor C3 is grounded. The anode of the freewheeling diode D3 is grounded. Among them, pin 1 and pin 2 of the flyback power supply chip U1 are GND ground pins, pin 3 is the feedback pin, pin 4 is the VDD power supply pin, pin 5 is the high-voltage input pin, pin 6 is a non-functional pin and remains floating, and pin 8 is the drain pin of the on-chip Mos tube; One end of the filter capacitor C3 is also used to connect the control end of the discharge module through the normally closed contact of the relay K1 in the suspension controller control circuit, or to access the suspension controller control circuit through the normally open contact of the relay K1.

3. The suspension controller discharge circuit according to claim 1 or 2, characterized in that, The input filter module includes a unidirectional conduction diode D1 and a polarized capacitor EB1. The positive electrode of the unidirectional conduction diode D1 is used to connect the system power input circuit. The negative electrode of the unidirectional conduction diode D1 is respectively connected to the input end of the discharge control module and the positive electrode of the polarized capacitor EB1. The negative electrode of the polarized capacitor EB1 is grounded.

4. The suspension controller discharge circuit according to claim 3, characterized in that, The discharge module includes a relay K2 and a resistor R2. One end of the coil of the relay K2 is connected to the output end of the discharge control module. The other end of the coil of the relay K2 is grounded. Among the pair of normally open contacts of the relay K2, one contact is used to connect the system power input circuit, and the other contact is connected to one end of the resistor R2. The other end of the resistor R2 is grounded.

5. A suspension controller discharge circuit, characterized in that, It includes an input filter module, a discharge control module and a discharge module; The input end of the input filter module is used to connect the system power input circuit. The input end of the discharge module is used to connect the system power input circuit. The output end of the discharge module is grounded; The input filter module is used to filter the input voltage introduced by the system power input circuit during the floating power-on stage of the floating controller control circuit. The discharge module remains closed during the floating power-on stage of the floating controller control circuit. The discharge control module is used to control the discharge module to discharge the bus voltage during the floating power-off stage of the floating controller control circuit; Wherein, the discharge control module includes a flyback power supply unit, a low-pass filter unit, and an output voltage feedback loop; The output end of the input filter module is connected to the input end of the flyback power supply unit. The output end of the flyback power supply unit is connected to the input end of the low-pass filter unit. The feedback input end of the flyback power supply unit is connected to the output end of the output voltage feedback loop. The feedback input end of the flyback power supply unit is also used to connect to the floating controller control circuit. The output end of the low-pass filter unit is respectively connected to the input end of the output voltage feedback loop and the control end of the discharge module; During the floating power-on stage of the floating controller control circuit, the flyback power supply unit is powered by the input filter module, and the flyback power supply unit remains closed under the control power supply voltage provided by the floating controller control circuit; During the floating power-off stage of the floating controller control circuit, the control power supply voltage provided by the floating controller control circuit loses voltage. The flyback power supply unit starts to work and outputs a control voltage to the discharge module through the low-pass filter unit until the input voltage of the flyback power supply unit is lower than the working voltage of the flyback power supply unit.

6. The floating controller discharge circuit according to claim 5, characterized in that, The flyback power supply unit includes a flyback power supply chip U1 and a filter capacitor C1. The output voltage feedback loop includes a loop resistor RF1, a loop resistor RF2, a loop capacitor C2, and a unidirectional conduction diode D2. The low-pass filter unit includes a filter inductor L1, a filter capacitor C3, and a freewheeling diode D3; Pin 5 and pin 8 of the flyback power supply chip U1 are respectively connected to the output end of the input filter module. Pin 4 of the flyback power supply chip U1 is connected to one end of the filter capacitor C1. The other end of the filter capacitor C1 is respectively connected to one end of the loop resistor RF2, one end of the loop capacitor C2, one end of the filter inductor L1, the negative electrode of the freewheeling diode D3, pin 1 and pin 2 of the flyback power supply chip U1. The other end of the loop resistor RF2 is respectively connected to one end of the loop resistor RF1 and pin 3 of the flyback power supply chip U1. The other end of the loop resistor RF1 is respectively connected to the other end of the loop capacitor C2 and the negative electrode of the unidirectional conduction diode D2. The positive electrode of the unidirectional conduction diode D2 is respectively connected to the other end of the filter inductor L1, one end of the filter capacitor C3 and the control end of the discharge module. The other end of the filter capacitor C3 is grounded. The positive electrode of the freewheeling diode D3 is grounded; among them, pin 1 and pin 2 of the flyback power supply chip U1 are GND ground pins, pin 3 is a feedback pin, pin 4 is a VDD power supply pin, pin 5 is a high voltage input pin, pin 6 is a non-functional pin and remains floating, and pin 8 is the drain pin of the on-chip Mos tube; The other end of the loop capacitor C2 is also used to connect the control power supply of the suspension controller control circuit. One end of the loop capacitor C2 is also used to connect the control power supply ground of the suspension controller control circuit.

7. The suspension controller discharge circuit according to claim 6, characterized in that, further comprising a current limiting resistor R3 and a unidirectional conduction diode D4. One end of the current limiting resistor R3 is connected to the other end of the loop capacitor C2. The other end of the current limiting resistor R3 is connected to the negative electrode of the unidirectional conduction diode D4. The positive electrode of the unidirectional conduction diode D4 is used to connect the control power supply of the suspension controller control circuit.

8. The suspension controller discharge circuit according to any one of claims 5 to 7, characterized in that, The input filter module includes a unidirectional conduction diode D1 and a polarized capacitor EB1. The positive electrode of the unidirectional conduction diode D1 is used to connect the system power input circuit. The negative electrode of the unidirectional conduction diode D1 is respectively connected to the input end of the discharge control module and the positive electrode of the polarized capacitor EB1. The negative electrode of the polarized capacitor EB1 is grounded.

9. The suspension controller discharge circuit according to claim 8, characterized in that, The discharge module includes a relay K2 and a resistor R2. One end of the coil of the relay K2 is connected to the output end of the discharge control module. The other end of the coil of the relay K2 is grounded. Among a pair of normally open contacts of the relay K2, one contact is used to connect the system power input circuit, and the other contact is connected to one end of the resistor R2. The other end of the resistor R2 is grounded.

10. A suspension control system, characterized in that, comprises a system power input circuit, a suspension controller control circuit and the suspension controller discharge circuit according to any one of claims 1 to 9. The system power input circuit is used to connect the system input power supply.

11. The suspension control system according to claim 10, characterized in that, the system power input circuit includes a positive connector VIN+, a negative connector VIN-, a system main contactor KM1, a system auxiliary contactor KM2, a current limiting resistor R1, and a system input filter capacitor E1; the positive connector VIN+ is used to connect the positive terminal of the system input power supply, and the negative connector VIN- is used to connect the negative terminal of the system input power supply; in a pair of normally open contacts of the system main contactor KM1, one contact is connected to the positive connector VIN+, and the other contact is respectively connected to one end of the current limiting resistor R1, the positive electrode of the system input filter capacitor E1, and the input end of the suspension controller discharge circuit. One end of the coil of the system main contactor KM1 is connected to the drive output end of the suspension controller control circuit, and the other end of the coil of the system main contactor KM1 is grounded; in a pair of normally open contacts of the system auxiliary contactor KM2, one contact is connected to the positive connector VIN+, and the other contact is respectively connected to the other end of the current limiting resistor R1 and the input end of the discharge module in the suspension controller discharge circuit. One end of the coil of the system auxiliary contactor KM2 is connected to the drive output end of the suspension controller control circuit, and the other end of the coil of the system auxiliary contactor KM2 is grounded; the negative electrode of the system input filter capacitor E1 is grounded.

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