Active short circuit control circuit and method

Abstract

The present invention discloses an active short-circuit control circuit and method, the circuit includes: an overvoltage detection module, an active short-circuit module and a drive control module, when the overvoltage detection module detects that the motor power supply voltage exceeds a preset range and / or the controller control software fails, a first fault signal is sent to the active short-circuit module; the active short-circuit module is used to disconnect the connection between the controller and the drive control module, and send an active short-circuit control signal to the drive control module to adjust the switch tube in the drive control module, so as to control the motor to an active short-circuit safety state, solve the problem in the prior art that the motor output safety torque cannot be guaranteed after the control software fails, and further improve driving safety. In addition, after a fault occurs, the connection between the controller and the drive control module is disconnected to ensure that the controller is not damaged, thereby improving the service life of the motor controller.

Description

Technical Field

[0001] The present invention relates to the field of automobile control, and in particular to an active short-circuit control circuit and method. Background Art

[0002] With the widespread popularity of new energy vehicles, the motor controller in electric vehicles is an important part of the vehicle power system, responsible for converting high-voltage direct current into alternating current to drive the motor, thereby providing power for the vehicle. However, the failure of the motor's external system may cause motor failure, which in turn may damage the motor controller and cause the output to be out of control, making it impossible for the motor controller to output according to the instructions given by the vehicle controller. In addition, when only the motor fails and the motor controller is normal, such as when a unidirectional short circuit occurs in the motor winding, the impact on the vehicle is reflected in unexpected rapid acceleration and deceleration of the vehicle, threatening the vehicle and personal safety.

[0003] When a motor fault is detected in the traditional protection circuit, the motor is controlled to enter a safe state. Usually, there are two safe states for the motor. One is to directly put all power switch devices in an open circuit state (Free Wheeling, FW); the other is to put the half bridge of the power switch device in an open circuit and the opposite half bridge in a short circuit, also known as active three-phase short circuit (Active Short Circuit, ASC). When the motor is running at high speed, in order to avoid the generation of reverse electromotive force, the motor is controlled to enter the ASC safe state; when the motor is running at low speed, the motor is controlled to enter the FW state. However, when the low-voltage power supply fails or the control software fails, the functional safety protection of the motor cannot be guaranteed, which has limitations. Summary of the invention

[0004] The embodiment of the present invention provides an active short-circuit control circuit and method. When a motor fails, the motor is put into a safe state through an active short-circuit method, the output torque is stabilized, and driving safety is ensured.

[0005] In a first aspect, an embodiment of the present invention provides an active short circuit control circuit, comprising: an overvoltage detection module, an active short circuit module and a drive control module;

[0006] The drive control module includes a plurality of switch tubes, and the switch tubes are used to adjust the power supply voltage of the motor;

[0007] The overvoltage detection module is electrically connected to the motor, the drive control module and the controller respectively, and is used to detect the motor power supply voltage and the control software of the controller;

[0008] The overvoltage detection module is used to send a first fault signal to the active short-circuit module when the motor supply voltage exceeds a preset range and / or the controller control software fails; the active short-circuit module is used to disconnect the connection between the controller and the drive control module, and send an active short-circuit control signal to the drive control module.

[0009] In a second aspect, an embodiment of the present invention provides an active short circuit control method, the method comprising:

[0010] Step 1: Determine whether the controller has a low-voltage power supply failure. If yes, start the backup power supply so that the backup power supply supplies power to the overvoltage detection module, the active short-circuit module and the drive control module respectively, and then execute step 2; if no, directly execute step 2;

[0011] Step 2: The overvoltage detection module detects whether the motor supply voltage exceeds a preset range and / or the controller control software fails. If so, the process proceeds to step 3; if not, the original state of the controller is maintained;

[0012] Step 3: Sending a first fault signal to the active short-circuit module;

[0013] Step 4: The active short-circuit module disconnects the connection between the controller and the drive control module, and sends an active short-circuit control signal to the drive control module.

[0014] The technical solution provided by the embodiment of the present invention is that when the overvoltage detection module detects that the motor power supply voltage exceeds the preset range and / or the controller control software fails, a first fault signal is sent to the active short-circuit module; the active short-circuit module is used to disconnect the connection between the controller and the drive control module, and send an active short-circuit control signal to the drive control module to adjust the switch tube in the drive control module, thereby controlling the motor to enter the active short-circuit safety state, solving the problem in the prior art that the motor output safety torque cannot be guaranteed when the control software fails, and further improving driving safety. In addition, after a fault occurs, the connection between the controller and the drive control module is disconnected to ensure that the controller is not damaged, thereby increasing the service life of the motor controller. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 A schematic diagram of the structure of an active short-circuit control circuit provided in Embodiment 1 of the present invention;

[0016] Figure 2 A schematic diagram of the structure of another active short-circuit control circuit provided in Embodiment 1 of the present invention;

[0017] Figure 3 A schematic diagram of the structure of an active short-circuit control circuit provided in Embodiment 2 of the present invention;

[0018] Figure 4 A schematic diagram of the structure of an active short-circuit control circuit provided in Embodiment 3 of the present invention;

[0019] Figure 5 A schematic diagram of a specific connection structure of an active short-circuit module provided in Embodiment 3 of the present invention;

[0020] Figure 6 A flowchart of an active short circuit control method provided in Embodiment 4 of the present invention;

[0021] Figure 7 This is a flow chart of another active short circuit control method provided in Embodiment 4 of the present invention. DETAILED DESCRIPTION

[0022] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0023] Embodiment 1

[0024] Figure 1 The schematic diagram of the structure of an active short-circuit control circuit provided in the first embodiment of the present invention is a circuit that can send an active short-circuit control signal when a motor fault is detected, thereby ensuring that the motor outputs a safe torque. The circuit includes: an overvoltage detection module 110, an active short-circuit module 120 and a drive control module 130;

[0025] The drive control module 130 includes a plurality of switch tubes, and the switch tubes are used to adjust the power supply voltage of the motor;

[0026] The overvoltage detection module 110 is electrically connected to the motor, the drive control module 130 and the controller respectively, and is used to detect the motor supply voltage and the control software of the controller;

[0027] The overvoltage detection module 110 is used to send a first fault signal to the active short-circuit module 120 when the motor supply voltage exceeds a preset range and / or the controller control software fails; the active short-circuit module 120 is used to disconnect the connection between the controller and the drive control module 130, and send an active short-circuit control signal to the drive control module 130.

[0028] The motor control circuit for electric vehicles currently mainly uses a three-phase bridge inverter to realize the conversion function between DC and AC. According to the control principle of the three-phase bridge inverter circuit, under normal operation, in a sinusoidal cycle, each bridge arm switch tube is turned on for half a cycle, and the upper and lower bridge arm switches of the same phase are turned on alternately. The angle difference between the start of conduction of each phase is 120 degrees, and at any moment, three bridge arms are turned on at the same time, but the upper and lower switches of the same-phase bridge arm cannot be turned on at the same time.

[0029] Specifically, the drive control module 130 includes a plurality of switch tubes, which can be divided into: an upper three-bridge switch tube and a lower three-bridge switch tube. The circuit corresponding to the upper three-bridge switch tube is a high-side circuit, and the circuit corresponding to the lower three-bridge switch tube is a low-side circuit. During normal operation, the upper three-bridge switch tube and the lower three-bridge switch tube are alternately turned on to realize the controller's control of the motor. When a fault occurs, an active short circuit can be realized by controlling the closing and opening of the upper three-bridge switch tube or the lower three-bridge switch tube.

[0030] Specifically, the overvoltage detection module 110 is electrically connected to the motor, the drive control module 130 and the motor controller, i.e., the controller, respectively, to detect the motor supply voltage and the control software of the controller. The overvoltage detection module 110 is also used to send a first fault signal to the active short-circuit module 120 when the motor supply voltage exceeds a preset range and / or the controller control software fails; the active short-circuit module 120 is used to disconnect the connection between the controller and the drive control module 130, and send an active short-circuit control signal to the drive control module 130.

[0031] It is understandable that when the motor supply voltage, that is, the operating voltage, exceeds the rated preset range, it indicates that the motor is operating abnormally. When the overvoltage detection module 110 detects that the motor supply voltage exceeds the preset range, a first fault signal can be sent. The preset range can be set according to the actual situation of the vehicle and is not specifically limited here. For example, when it is detected that the motor supply voltage exceeds 60V, a first fault signal is sent to the active short-circuit module 120; in addition, when the motor is working normally, the controller sends a PWM control signal to the drive control module 130. When the internal components of the controller have short circuits, open circuits, and other faults, the controller will be unable to send a control signal, that is, the controller control software fails, and the motor cannot be controlled to operate normally. In this embodiment, when the overvoltage detection module 110 detects that the controller control software fails, a first fault signal can also be sent to the active short-circuit module 120.

[0032] Furthermore, when the motor fails but the controller is able to operate normally, in order to ensure that the controller is not damaged, the active short-circuit module 120 will automatically disconnect the connection between the controller and the drive control module 130 after receiving the first fault signal issued by the overvoltage detection module 110, and send an active short-circuit control signal to the drive control module 130, and the drive control module 130 implements active short-circuiting.

[0033] Figure 2 FIG. 1 is a schematic diagram of another active short-circuit control circuit provided in Embodiment 1 of the present invention. Figure 1 The active short circuit control circuit shown in the figure is further refined. For details, please refer to Figure 2 Optionally, the active short circuit control circuit may further include:

[0034] Backup power supply 140; The backup power supply 140 is electrically connected to the overvoltage detection module 110, the active short-circuit module 120 and the drive control module 130 respectively, and is used to power the overvoltage detection module 110, the active short-circuit module 120 and the drive control module 130 when the low-voltage power supply of the controller fails.

[0035] Optionally, before the overvoltage detection module 110 detects the motor power supply voltage, it can also detect whether the controller low-voltage power supply is working normally. When it is detected that the controller low-voltage power supply fails, the backup power supply 140 supplies power to the overvoltage detection module 110, the active short-circuit module 120 and the drive control module 130. The specific setting method of the backup power supply 140 is not limited. For example, it can be a battery that can directly supply power to the low-voltage side, or it can be a power conversion device that can draw power from the high-voltage side.

[0036] The setting of the backup power supply can prevent the overvoltage detection module, the active short-circuit module and the drive control module from being affected by the abnormal low-voltage power supply of the controller. In the event of failure of the low-voltage power supply of the controller, they can still perform their respective functions normally.

[0037] Optionally, the overvoltage detection module 110 is also used to send a fault repair completion signal to the active short-circuit module 120 when it is detected that the motor power supply voltage has recovered to within a preset range; the active short-circuit module 120 is also used to establish a connection between the controller and the drive control module 130, and stop sending the active short-circuit control signal to the drive control module 130.

[0038] Specifically, after the active short circuit is executed, the overvoltage detection module 110 can monitor the motor supply voltage in real time. When it is detected that the voltage has recovered to within the preset range, it means that the motor can work normally. At this time, the overvoltage detection module 110 sends a fault repair completion signal to the active short circuit module 120, and reports the current state to the controller, so that the controller can monitor and record the active short circuit, providing a basis for subsequent optimization of the motor controller. After receiving the fault repair completion signal, the active short circuit module 120 re-establishes the connection between the controller and the drive control module 130, and the controller re-sends the PWM control signal to control the switch tube in the drive control module 130 to close or disconnect, thereby realizing the control of the motor. At the same time, the active short circuit module 120 stops sending the active short circuit control signal to make the motor control circuit exit the active short circuit state.

[0039] The technical solution provided in the first embodiment of the present invention is that when the overvoltage detection module detects that the motor power supply voltage exceeds the preset range and / or the controller control software fails, a first fault signal is sent to the active short-circuit module; the active short-circuit module is used to disconnect the connection between the controller and the drive control module, and send an active short-circuit control signal to the drive control module to adjust the switch tube in the drive control module, thereby controlling the motor to enter the active short-circuit safety state, solving the problem in the prior art that the motor output safety torque cannot be guaranteed when the control software fails, and further improving driving safety. In addition, after a fault occurs, the connection between the controller and the drive control module is disconnected to ensure that the controller is not damaged, thereby increasing the service life of the motor controller.

[0040] Embodiment 2

[0041] Figure 3 FIG. 1 is a schematic diagram of a structure of an active short-circuit control circuit provided in Embodiment 2 of the present invention. The active short-circuit control circuit provided in Embodiment 2 is further refined on the basis of Embodiment 1 above. For details, see Figure 3 , the active short circuit control circuit may also include:

[0042] Driving fault detection module 150; the driving fault detection module 150 is used to detect the switch tube of the driving control module 130; the driving fault detection module 150 is electrically connected to the active short-circuit module 120, and is used to send a second fault signal to the active short-circuit module 120 when a fault occurs in the switching tube; the active short-circuit module 120 is used to send an active short-circuit control signal to the driving control module 130.

[0043] Optionally, the specific setting method of the drive fault detection module 150 is not limited here. For example, it can be set separately, or it can be set together with the drive overvoltage detection module 110, or it can be set in the drive control module 130. In the present embodiment, it is preferably set separately. The additional setting of the drive fault detection module 150 can make a more direct and accurate judgment on the fault of the motor, thereby issuing a clear fault instruction.

[0044] Furthermore, the drive fault detection module 150 can also be electrically connected to the overvoltage detection module 110 and the drive control module 130. After detecting the first fault signal sent by the overvoltage detection module 110, the drive fault detection module 150 detects the switch tube of the drive control module 130. It can be understood that at this time, the drive fault detection module 150 can not only detect whether each switch tube itself has a fault, but also detect whether the high-side circuit corresponding to the upper three-bridge switch tube and / or the low-side circuit corresponding to the lower three-bridge switch tube has a fault.

[0045] Optionally, the second fault signal may include an upper three-bridge fault signal or a lower three-bridge fault signal, the upper three-bridge fault signal refers to a fault of the upper three-bridge switch tube itself and / or a fault of the high-side circuit corresponding to the upper three-bridge switch tube; the lower three-bridge fault signal refers to a fault of the lower three-bridge switch tube itself and / or a fault of the low-side circuit corresponding to the lower three-bridge switch tube.

[0046] Furthermore, when the driving fault detection module 150 detects that the switch tube fails, it sends a second fault signal to the active short-circuit module 120 ; after receiving the second fault signal, the active short-circuit module 120 sends an active short-circuit control signal to the driving control module 130 .

[0047] Optionally, the active short-circuit module 120 may also be used to control the switch tubes of the upper three bridges of the drive control module 130 to be disconnected and control the switch tubes of the lower three bridges to be closed when it is detected that the second fault signal sent by the drive fault detection module 150 is an upper three-bridge fault signal;

[0048] The active short-circuit module 120 is used to control the switch tubes of the lower three bridges of the drive control module 130 to be disconnected and the switch tubes of the upper three bridges to be closed when it is detected that the second fault signal sent by the drive fault detection module 150 is a lower three-bridge fault signal.

[0049] It can be understood that when the upper three-bridge switch tube itself fails and / or the high-side circuit corresponding to the upper three-bridge switch tube fails, in order to achieve active short circuit and ensure that the motor outputs safe torque, the upper three-bridge switch tube should be disconnected and the lower three-bridge switch tube should be closed. A loop is formed between the lower three-bridge switch tubes, so that a loop cannot be effectively formed between the motor and the controller, thereby preventing abnormal torque output.

[0050] Fault detection and active short-circuit control are carried out alternately, that is, when the switch of the upper three bridges reports a fault, the lower three bridges implement active short circuit; when the switch of the lower three bridges reports a fault, the upper three bridges implement active short circuit, which can ensure the realization of the active short-circuit function to ensure driving safety.

[0051] Similarly, when the lower three-bridge switch tube itself fails and / or the low-side circuit corresponding to the lower three-bridge switch tube fails, the lower three-bridge switch tube should be disconnected and the upper three-bridge switch tube should be closed, forming a loop between the upper three-bridge switch tubes, making it impossible to effectively form a loop between the motor and the controller, thereby preventing abnormal torque output.

[0052] Optionally, the closing and opening of each switch tube in the drive control module 130 can be controlled by multiple drive chips in the drive control module 130. After the drive control module 130 receives an active short-circuit control signal, the drive chip controls the upper three-bridge switch tube or the lower three-bridge switch tube to complete the active short-circuit according to the active short-circuit control signal.

[0053] The active short-circuit module is arranged on the left side of the driver chip, that is, the driver low-voltage side. It has low requirements on the driver chip and can be implemented using a simple driver chip. It is highly economical and convenient for large-scale promotion.

[0054] Optionally, when the overvoltage detection module 110 detects that the motor supply voltage exceeds the voltage threshold and / or the controller control software fails, the active short-circuit module 120 controls the switch tubes of the upper three bridges of the drive control module 130 to be disconnected and the switch tubes of the lower three bridges to be closed.

[0055] It should be noted that in the technical solution provided by the embodiment of the present invention, when the overvoltage detection module 110 detects that a fault has occurred, a default working state can be set, that is, the lower three-bridge switch tube or the upper three-bridge switch tube works by default, that is, the lower three bridges are actively short-circuited or the lower three bridges are actively short-circuited, and then the fault detection module 150 is driven to detect the fault type and send different fault signals.

[0056] Optionally, if the switch tubes of the lower three bridges are working by default, the active short-circuit module 120 directly controls the switch tubes of the upper three bridges of the drive control module 130 to be disconnected, and the switch tubes of the lower three bridges to be closed; if the switch tubes of the upper three bridges are working by default, the active short-circuit module 120 directly controls the switch tubes of the lower three bridges of the drive control module 130 to be disconnected, and the switch tubes of the upper three bridges to be closed.

[0057] By setting the default working state, active short circuit can be achieved at the first time of fault occurrence, avoiding abnormal operation of the motor during vehicle driving, which may cause excessive back electromotive force to damage the power battery, bus capacitor and other high-voltage devices.

[0058] The technical solution provided in the second embodiment of the present invention, after receiving the first fault signal, drives the fault detection module to detect the fault type, and sends different fault signals for different fault types, so that the active short-circuit module sends corresponding active short-circuit control signals for different fault signals, and drives the control module to make different short-circuit controls, thereby completing the active short-circuit work in the motor control circuit more accurately and directly.

[0059] Embodiment 3

[0060] Figure 4 FIG. 1 is a schematic diagram of a structure of an active short-circuit control circuit provided in Embodiment 3 of the present invention. The active short-circuit control circuit provided in Embodiment 3 is refined on the basis of the above-mentioned embodiments. For details, see Figure 4 , wherein the active short-circuit module 120 may further include:

[0061] A first logic circuit 11, a second logic circuit 12, a third logic circuit 13 and a delay circuit 14;

[0062] The first logic circuit 11 is electrically connected to the controller, the overvoltage detection module 110 and the drive control module 130 respectively, and is used to disconnect the connection with the controller after receiving the first fault signal;

[0063] The second logic circuit 12 is electrically connected to the overvoltage detection module 110 and the delay circuit 14, respectively, and is used to send a delay control signal to the delay circuit 14 after receiving the second fault signal, and send an active short circuit control signal to the third logic circuit 13; the delay circuit 14 is used to send an enable signal to the third logic circuit 13 after a set delay time;

[0064] The third logic circuit 13 is used to send an active short-circuit control signal to the drive control module 130 after receiving the enable signal.

[0065] Under normal working conditions, the controller sends out a PWM control signal, which is transmitted to the drive control module 130 after passing through the first logic circuit 11 and the third logic circuit 13 to control the switch tube to open or close, thereby controlling the motor to work. When the overvoltage detection module 110 detects a fault and sends out a first fault signal, the first logic circuit 11 is disconnected, that is, the PWM control signal sent by the controller is disconnected.

[0066] Optionally, the specific configuration of the first logic circuit 11 is not limited here, and in this embodiment, it is preferably implemented by a multi-way switch. Specifically, during normal operation, the first logic circuit 11 receives a high-level signal, and after the overvoltage detection module 110 detects a fault, it sends a first fault signal to the first logic circuit 11. At this time, the first fault signal is a low-level signal. After receiving the low-level signal, the first logic circuit 11 controls the multi-way switch to disconnect, that is, disconnects the PWM control signal sent by the controller.

[0067] Optionally, the second logic circuit 12 can also be connected to the driving fault detection module 150. After the driving fault detection module 150 makes a judgment on the fault type, it sends an upper three-bridge fault signal or a lower three-bridge fault signal to the second logic circuit 12. The second logic circuit 12 sends a corresponding active short-circuit control signal according to the fault type, and the active short-circuit control signal is sent to the third logic circuit 13 through the delay circuit 14; at the same time, the second logic circuit 12 sends a delay control signal to the delay circuit 14, and the delay circuit 14 is used to send an enable signal to the third logic circuit 13 after receiving the delay control signal and setting the delay time. Among them, the specific setting method of the delay circuit 14 can adopt any existing technology, which is not limited here. The present embodiment is preferably constructed by a simple RC delay circuit. The delay time of the RC delay circuit can be adjusted by the size of the resistor and the capacitor. The circuit is simple and easy to use.

[0068] Furthermore, after receiving the enable signal, the third logic circuit 13 sends the active short circuit control signal sent by the second logic circuit 12 to the drive control module 130 to complete the active short circuit operation.

[0069] Optionally, the specific setting method of the third logic circuit 13 is not limited here, and it is also preferably implemented by a multi-way switch in this embodiment. Specifically, during normal operation, the first logic circuit 13 receives a high-level signal. After a fault occurs, the second logic circuit 12 sends a delay control signal and an active short-circuit control signal. After the delay circuit 14 receives the delay control signal, it sends an enable signal after a certain delay time, which can be several microseconds. The enable signal controls the multi-way switch in the third logic circuit 13 to close, so that the active short-circuit control signal is sent to the drive control module 130. By setting the delay circuit 14, it can prevent the upper and lower switches of the same bridge arm from being directly connected when the upper three bridges and the lower three bridges are switched to the active short-circuit state, causing a short-circuit shock.

[0070] Optionally, the second logic circuit 12 may further include an upper three-bridge logic control circuit 122 and a lower three-bridge logic control circuit 121;

[0071] When the active short-circuit module 120 detects that the second fault signal sent by the driving fault detection module 150 is an upper three-bridge fault signal, the upper three-bridge logic control circuit 122 sends a disconnect signal of the switch tube of the upper three bridges to the third logic circuit 13; the lower three-bridge logic control circuit 121 sends a closing signal of the switch tube of the lower three bridges to the third logic circuit 13;

[0072] When the active short-circuit module 120 detects that the second fault signal sent by the driving fault detection module 150 is a lower three-bridge fault signal, the upper three-bridge logic control circuit 122 sends a closing signal of the switch tube of the upper three bridges to the third logic circuit 13; the lower three-bridge logic control circuit 121 sends a disconnecting signal of the switch tube of the lower three bridges to the third logic circuit 13.

[0073] Optionally, in this embodiment, the upper three-bridge logic control circuit 122 and / or the lower three-bridge logic control circuit 121 are preferably implemented by setting a pull-up resistor and / or a pull-down resistor.

[0074] Specifically, when a fault occurs in the upper three bridges, the lower three bridge logic control circuit 121 pulls up the signal to the power supply voltage through a pull-up resistor, and the switch corresponding to the lower three bridge switch tube in the third logic circuit 13 is closed; at the same time, the upper three bridge logic control circuit 122 pulls down the signal to 0V through a pull-down resistor, and the switch corresponding to the upper three bridge switch tube in the third logic circuit 13 is disconnected, and finally the third logic circuit 13 sends an active short-circuit control signal for the lower three bridges.

[0075] Similarly, when a fault occurs in the lower three bridges, the upper three bridge logic control circuit 122 pulls up the signal to the power supply voltage through a pull-up resistor, and the switch corresponding to the upper three bridge switch tube in the third logic circuit 13 is closed; at the same time, the lower three bridge logic control circuit 121 pulls down the signal to 0V through a pull-down resistor, and the switch corresponding to the lower three bridge switch tube in the third logic circuit 13 is disconnected, and finally the third logic circuit 13 sends an active short-circuit control signal for the upper three bridges.

[0076] In the technical solution provided in the third embodiment of the present invention, the active short-circuit module is constructed by a simple logic circuit, and the active short-circuit function can be realized without a complex circuit structure. The circuit has high stability and good practical value.

[0077] On the basis of the above embodiments, the present invention also exemplarily provides a specific connection method of each circuit in an active short-circuit module. Figure 5 The specific connection structure diagram of the active short-circuit module provided in the third embodiment of the present invention will be referred to below. Figure 5 Introduce the working process of the active short-circuit module:

[0078] During normal operation, the HV-OV received by the first logic circuit 11 is a high-level signal. After a fault occurs, the HV-OV signal becomes a low-level signal, namely the first fault signal LO signal. After the first logic circuit 11 receives the LO signal, the multi-way switch X1 is disconnected, and the PWM signal sent by the controller cannot continue to be transmitted. Subsequently, the lower three-bridge logic control circuit 121 and the upper three-bridge logic control circuit 122 control the active short-circuit operation of the drive control module 130; at the same time, the LO signal is transmitted to the delay circuit 14. After a short delay, the delay circuit 14 sends an enable signal, namely the LDO signal, to the third logic circuit 13. It should be noted that Figure 5 The default lower three bridges are actively short-circuited, that is, the input end of the lower three bridges logic control circuit 121 is connected to the pull-up resistor SA end, and the input end of the upper three bridges logic control circuit 122 is connected to the pull-down resistor SA end. It can be understood that if the upper three bridges are actively short-circuited by default, the opposite operation is performed.

[0079] Furthermore, FLT-L is a detected fault signal. If FLT-L is a fault signal of the lower three bridges, the input end of the lower three bridges logic control circuit 121 is connected to the end of the pull-down resistor SB, and the input end of the upper three bridges logic control circuit 122 is connected to the end of the pull-up resistor SB, that is, the lower three bridges logic control circuit 121 and the upper three bridges logic control circuit 122 respectively send signals to the third logic circuit 13 to disconnect the lower three bridge switches and close the upper three bridge switches, thereby realizing active short circuit of the upper three bridges; if FLT-L is a fault signal of the upper three bridges, the existing active short circuit state of the lower three bridges is still maintained.

[0080] Furthermore, after the third logic circuit 13 receives the LDO signal and the active short-circuit control signal issued by the lower three-bridge logic control circuit 121 or the upper three-bridge logic control circuit 122, the multi-way switch X2 is closed to transmit the active short-circuit control signal backward to the drive control module 130, thereby performing the active short-circuit operation.

[0081] Embodiment 4

[0082] Based on the same concept, the present invention also provides an active short circuit control method. Figure 6 This is a flow chart of an active short circuit control method provided in Embodiment 4 of the present invention. The active short circuit control method can be implemented by any active short circuit control circuit provided in the embodiments of the present invention, and the connection mode between the modules involved can also refer to the description in the above embodiments. The method includes:

[0083] S410, determining whether the controller has a low voltage power supply failure condition, if so, executing S420, and then executing S430; if not, directly executing S430.

[0084] S420, start the backup power supply so that the backup power supply supplies power to the overvoltage detection module, the active short circuit module and the drive control module respectively.

[0085] Optionally, the backup power supply is electrically connected to the overvoltage detection module, the active short-circuit module and the drive control module, respectively. Specifically, before the overvoltage detection module detects the motor power supply voltage, it can also detect whether the controller low-voltage power supply is working normally. When it is detected that the controller low-voltage power supply fails, the overvoltage detection module, the active short-circuit module and the drive control module are powered. There is no limitation on the specific setting method of the backup power supply. For example, it can be a battery that can directly supply power to the low-voltage side, or it can be a power conversion device that can draw power from the high-voltage side.

[0086] The setting of the backup power supply can prevent the overvoltage detection module, the active short-circuit module and the drive control module from being affected by the low-voltage power supply of the controller. In the event of failure of the low-voltage power supply of the controller, they can still perform their respective functions normally.

[0087] S430, the overvoltage detection module detects whether the motor supply voltage exceeds a preset range and / or the controller control software fails. If so, it goes to S440; if not, it goes to S460 and maintains the original state of the controller.

[0088] S440: Send a first fault signal to an active short-circuit module.

[0089] The overvoltage detection module is electrically connected to the motor, the drive control module and the controller respectively, and is used to detect the motor supply voltage and the control software of the controller;

[0090] The overvoltage detection module is used to send a first fault signal to the active short-circuit module when the motor supply voltage exceeds a preset range and / or the controller control software fails; the active short-circuit module is used to disconnect the connection between the controller and the drive control module, and send an active short-circuit control signal to the drive control module.

[0091] It is understandable that when the motor supply voltage, i.e., the operating voltage, exceeds the rated preset range, it indicates that the motor is operating abnormally. When the overvoltage detection module detects that the motor supply voltage exceeds the preset range, a first fault signal may be sent. The preset range may be set according to the actual situation of the vehicle and is not specifically limited here. For example, when the motor supply voltage is detected to be over 60V, a first fault signal may be sent to the active short-circuit module. In addition, when the motor is working normally, the controller sends a PWM control signal to the drive control module. When a short circuit, open circuit, or other fault occurs in the internal components of the controller, the controller may be unable to send a control signal, i.e., the controller control software may fail, thereby failing to control the normal operation of the motor. In this embodiment, when the overvoltage detection module detects that the controller control software fails, a first fault signal may also be sent to the active short-circuit module. After executing S440, execute S450.

[0092] S450: The active short-circuit module disconnects the connection between the controller and the drive control module, and sends an active short-circuit control signal to the drive control module.

[0093] Furthermore, when the motor fails but the controller is able to work normally, in order to ensure that the controller is not damaged, the active short-circuit module will automatically disconnect the connection between the controller and the drive control module after receiving the first fault signal issued by the overvoltage detection module, and send an active short-circuit control signal to the drive control module, and the drive control module implements active short-circuiting.

[0094] Specifically, the drive control module contains multiple switch tubes, which are used to adjust the power supply voltage of the motor. They can be divided into: upper three-bridge switch tubes and lower three-bridge switch tubes. The circuit corresponding to the upper three-bridge switch tube is the high-side circuit, and the circuit corresponding to the lower three-bridge switch tube is the low-side circuit. During normal operation, the upper three-bridge switch tube and the lower three-bridge switch tube are alternately turned on to realize the controller's control of the motor. When a fault occurs, active short circuit can be achieved by controlling the closing and opening of the upper three-bridge switch tube or the lower three-bridge switch tube.

[0095] Optionally, the above-mentioned active short-circuit module may include: a drive fault detection module; the drive fault detection module is used to detect the switch tube of the drive control module; the drive fault detection module is electrically connected to the active short-circuit module, and is used to send a second fault signal to the active short-circuit module when a switch tube fails; the active short-circuit module is used to send an active short-circuit control signal to the drive control module.

[0096] Optionally, the second fault signal may include an upper three-bridge fault signal or a lower three-bridge fault signal, the upper three-bridge fault signal refers to a fault of the upper three-bridge switch tube itself and / or a fault of the high-side circuit corresponding to the upper three-bridge switch tube; the lower three-bridge fault signal refers to a fault of the lower three-bridge switch tube itself and / or a fault of the low-side circuit corresponding to the lower three-bridge switch tube.

[0097] If the overvoltage detection module does not detect the above fault condition, the original state of the controller is maintained, that is, the motor is still driven by the controller to run.

[0098] Figure 7 A flowchart of another active short circuit control method provided in Embodiment 4 of the present invention. The active short circuit control method is Figure 6 The active short circuit control method is further refined based on the above, specifically, the active short circuit module is divided: the above active short circuit module can also include a first logic circuit, a second logic circuit, a third logic circuit and a delay circuit. That is, S450 can be refined as follows:

[0099] S451. After receiving the first fault signal, the first logic circuit disconnects from the controller.

[0100] It is understandable that when the motor fails but the controller can work normally, in order to ensure that the controller is not damaged, the active short-circuit module will automatically disconnect the connection between the controller and the drive control module after receiving the first fault signal sent by the overvoltage detection module.

[0101] Specifically, the first logic circuit is electrically connected to the controller, the overvoltage detection module and the drive control module respectively, and is used to disconnect the connection with the controller after receiving the first fault signal.

[0102] S452, the second logic circuit determines whether the second fault signal sent by the driving fault detection module is an upper three-bridge fault signal; if so, execute S453; if not, execute step S454.

[0103] Optionally, the second logic circuit is electrically connected to the overvoltage detection module and the delay circuit, respectively, and is used to send a delay control signal to the delay circuit after receiving the second fault signal, and to send an active short-circuit control signal to the third logic circuit; the delay circuit is used to send an enable signal to the third logic circuit after a set delay time; the third logic circuit is used to send the active short-circuit control signal to the drive control module after receiving the enable signal.

[0104] Optionally, the second fault signal may include an upper three-bridge fault signal or a lower three-bridge fault signal, the upper three-bridge fault signal refers to a fault of the upper three-bridge switch tube itself and / or a fault of the high-side circuit corresponding to the upper three-bridge switch tube; the lower three-bridge fault signal refers to a fault of the lower three-bridge switch tube itself and / or a fault of the low-side circuit corresponding to the lower three-bridge switch tube.

[0105] The second logic circuit detects whether the second fault signal is an upper three-bridge fault signal or a lower three-bridge fault signal. If it is an upper three-bridge fault signal, S453 is executed; if it is a lower three-bridge fault signal, S455 is executed.

[0106] S453, the second logic circuit controls the switch tubes of the upper three bridges of the drive control module to be disconnected, and controls the switch tubes of the lower three bridges to be closed.

[0107] Optionally, the active short-circuit module may be used to control the switch tubes of the upper three bridges of the drive control module to be disconnected and the switch tubes of the lower three bridges to be closed when it is detected that the second fault signal sent by the drive fault detection module is a fault signal of the upper three bridges;

[0108] Optionally, the second logic circuit may further include an upper three-bridge logic control circuit 122 and a lower three-bridge logic control circuit 121;

[0109] When the active short-circuit module detects that the second fault signal sent by the driving fault detection module is an upper three-bridge fault signal, the upper three-bridge logic control circuit 122 sends a disconnect signal of the switch tube of the upper three bridges to the third logic circuit; the lower three-bridge logic control circuit 121 sends a closing signal of the switch tube of the lower three bridges to the third logic circuit.

[0110] S454, the second logic circuit determines whether the second fault signal sent by the driving fault detection module is a lower three-bridge fault signal; if so, execute S455; if not, execute step S456.

[0111] It should be noted that in the technical solution provided by the embodiment of the present invention, when the overvoltage detection module detects that a fault has occurred, a default working state can be set, that is, the lower three-bridge switch tube or the upper three-bridge switch tube works by default, and then the fault detection module is driven to detect the fault type and send different fault signals.

[0112] This embodiment preferably sets the default lower three bridge switch tube operation, that is, when the overvoltage detection module detects that the motor power supply voltage exceeds the voltage threshold and / or the controller control software fails, the active short-circuit module controls the switch tubes of the upper three bridges of the drive control module to disconnect and the switch tubes of the lower three bridges to close.

[0113] Specifically, when the active short-circuit module detects the first fault signal sent by the overvoltage detection module, the switch tube of the upper three bridges of the drive control module is directly controlled to be disconnected and the switch tube of the lower three bridges is closed. Then the drive fault detection module detects the fault type. If the fault is detected to be a lower three bridge fault, S455 is executed to implement active short circuit of the upper three bridges; if it is not a lower three bridge fault, S456 is executed to maintain the default lower three bridge working state.

[0114] By setting the default working state, active short circuit can be achieved at the first time of fault occurrence, avoiding abnormal operation of the motor during vehicle driving, which may cause excessive back electromotive force to damage the power battery, bus capacitor and other high-voltage devices.

[0115] S455 , the second logic circuit controls the switch tubes of the lower three bridges of the drive control module to be disconnected, and the switch tubes of the upper three bridges to be closed.

[0116] The active short-circuit module is used to control the switch tubes of the lower three bridges of the drive control module to be disconnected and the switch tubes of the upper three bridges to be closed when it is detected that the second fault signal sent by the drive fault detection module is a lower three-bridge fault signal.

[0117] Specifically, when the active short-circuit module detects that the second fault signal sent by the driving fault detection module is a lower three-bridge fault signal, the upper three-bridge logic control circuit 122 sends a closing signal of the switch tube of the upper three bridges to the third logic circuit; the lower three-bridge logic control circuit 121 sends a disconnecting signal of the switch tube of the lower three bridges to the third logic circuit.

[0118] S456: The second logic circuit controls the switch tubes of the upper three bridges of the drive control module to be disconnected, and controls the switch tubes of the lower three bridges to be closed.

[0119] Optionally, after S450, the following may also be included:

[0120] S470, the overvoltage detection module determines whether the motor supply voltage is restored to a preset range, if so, execute S480,; if not, execute S490, maintain the active short circuit state of the active short circuit module.

[0121] S480: The active short-circuit module establishes a connection between the controller and the drive control module, and stops sending the active short-circuit control signal to the drive control module.

[0122] Optionally, the overvoltage detection module is also used to send a fault repair completion signal to the active short-circuit module when it detects that the motor power supply voltage has recovered to within a preset range; the active short-circuit module is also used to establish a connection between the controller and the drive control module, and stop sending the active short-circuit control signal to the drive control module.

[0123] Specifically, after the active short circuit is executed, the overvoltage detection module can monitor the motor supply voltage in real time. When it is detected that the voltage has recovered to the preset range, it means that the motor can work normally. At this time, the overvoltage detection module sends a fault repair completion signal to the active short circuit module and reports the current status to the controller, so that the controller can monitor and record the active short circuit, providing a basis for the subsequent optimization of the motor controller. After receiving the fault repair completion signal, the active short circuit module re-establishes the connection between the controller and the drive control module, and the controller re-sends the PWM control signal to control the switch tube in the drive control module to close or disconnect, thereby realizing the control of the motor. At the same time, the active short circuit module stops sending the active short circuit control signal to make the motor control circuit exit the active short circuit state.

[0124] The technical solution provided by the fourth embodiment of the present invention is that when the overvoltage detection module detects that the motor power supply voltage exceeds the preset range and / or the controller control software fails, a first fault signal is sent to the active short-circuit module; the active short-circuit module disconnects the connection between the controller and the drive control module, and sends an active short-circuit control signal to the drive control module to adjust the switch tube in the drive control module, thereby controlling the motor to an active short-circuit safety state, solving the problem in the prior art that the motor output safety torque cannot be guaranteed when the control software fails, and further improving driving safety. In addition, after a fault occurs, the connection between the controller and the drive control module is disconnected to ensure that the controller is not damaged, thereby increasing the service life of the motor controller.

[0125] Note that the above are only preferred embodiments of the present invention and the technical principles used. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in more detail through the above embodiments, the present invention is not limited to the above embodiments, and may include more other equivalent embodiments without departing from the concept of the present invention, and the scope of the present invention is determined by the scope of the appended claims.

Claims

1. An active short circuit control circuit, characterized in that: include: Overvoltage detection module, active short circuit module, drive control module and drive fault detection module; The drive control module includes a plurality of switch tubes, and the switch tubes are used to adjust the power supply voltage of the motor, wherein the switch tubes are divided into upper three-bridge switch tubes and lower three-bridge switch tubes, and active short circuit is realized by controlling the closing and opening of the upper three-bridge switch tubes or the lower three-bridge switch tubes; the closing and opening of each switch tube in the drive control module are controlled by a plurality of drive chips in the drive control module; The overvoltage detection module is electrically connected to the motor, the drive control module and the controller respectively, and is used to detect the motor power supply voltage and the control software of the controller; The overvoltage detection module is used to send a first fault signal to the active short-circuit module when the motor power supply voltage exceeds a preset range and / or the controller control software fails; the active short-circuit module is used to disconnect the controller from the drive control module and send an active short-circuit control signal to the drive control module; The driving fault detection module is used to detect the switch tube of the driving control module; the driving fault detection module is electrically connected to the active short-circuit module, and is used to send a second fault signal to the active short-circuit module when the switch tube fails; the active short-circuit module is used to send an active short-circuit control signal to the driving control module; Among them, the active short-circuit module includes: a first logic circuit, a second logic circuit, a third logic circuit and a delay circuit; the first logic circuit is electrically connected to the controller, the overvoltage detection module and the drive control module, respectively, and is used to disconnect the connection with the controller after receiving the first fault signal; the second logic circuit is electrically connected to the overvoltage detection module and the delay circuit, respectively, and is used to send a delay control signal to the delay circuit after receiving the second fault signal, and send an active short-circuit control signal to the third logic circuit; the delay circuit is used to send an enable signal to the third logic circuit after setting the delay time; the third logic circuit is used to send the active short-circuit control signal to the drive control module after receiving the enable signal.

2. The active short circuit control circuit according to claim 1, characterized in that: Also includes: Backup power supply; The backup power supply is electrically connected to the overvoltage detection module, the active short-circuit module and the drive control module respectively, and is used to power the overvoltage detection module, the active short-circuit module and the drive control module when the low-voltage power supply of the controller fails.

3. The active short circuit control circuit according to claim 1, characterized in that: The active short-circuit module is used to control the switch tubes of the upper three bridges of the drive control module to be disconnected and the switch tubes of the lower three bridges to be closed when detecting that the second fault signal sent by the drive fault detection module is a fault signal of the upper three bridges; The active short-circuit module is used to control the switch tubes of the lower three bridges of the drive control module to be disconnected and the switch tubes of the upper three bridges to be closed when it is detected that the second fault signal sent by the drive fault detection module is a lower three-bridge fault signal.

4. The active short circuit control circuit according to claim 1, characterized in that: When the overvoltage detection module detects that the motor supply voltage exceeds the voltage threshold and / or the controller control software fails, the active short-circuit module controls the switch tubes of the upper three bridges of the drive control module to be disconnected and the switch tubes of the lower three bridges to be closed.

5. The active short circuit control circuit according to claim 1, characterized in that: The second logic circuit includes an upper three-bridge logic control circuit and a lower three-bridge logic control circuit; When the active short-circuit module detects that the second fault signal sent by the drive fault detection module is an upper three-bridge fault signal, the upper three-bridge logic control circuit sends a disconnect signal of the switch tube of the upper three bridges to the third logic circuit; the lower three-bridge logic control circuit sends a closing signal of the switch tube of the lower three bridges to the third logic circuit; When the active short-circuit module detects that the second fault signal sent by the driving fault detection module is a lower three-bridge fault signal, the upper three-bridge logic control circuit sends a closing signal of the switch tube of the upper three bridges to the third logic circuit; the lower three-bridge logic control circuit sends a disconnecting signal of the switch tube of the lower three bridges to the third logic circuit.

6. The active short circuit control circuit according to claim 1, characterized in that: The overvoltage detection module is also used to send a fault repair completion signal to the active short-circuit module when it is detected that the motor power supply voltage has recovered to within a preset range; the active short-circuit module is also used to establish a connection between the controller and the drive control module, and stop sending the active short-circuit control signal to the drive control module.

7. An active short circuit control method, characterized in that: Applicable to the active short circuit control circuit according to any one of claims 1 to 6 above, the active short circuit control method comprising: Step 1: Determine whether the controller has a low-voltage power supply failure. If yes, start the backup power supply so that the backup power supply supplies power to the overvoltage detection module, the active short-circuit module and the drive control module respectively, and then execute step 2; if no, directly execute step 2; Step 2: The overvoltage detection module detects whether the motor supply voltage exceeds a preset range and / or the controller control software fails. If so, the process proceeds to step 3; if not, the original state of the controller is maintained; Step 3: Sending a first fault signal to the active short-circuit module; Step 4: The active short-circuit module disconnects the connection between the controller and the drive control module, and sends an active short-circuit control signal to the drive control module.

8. The active short circuit control method according to claim 7, characterized in that: The active short-circuit module includes: a first logic circuit, a second logic circuit, a third logic circuit and a delay circuit; the step 4 includes: Step 5: After receiving the first fault signal, the first logic circuit disconnects from the controller; Step 6: The second logic circuit determines whether the second fault signal sent by the drive fault detection module is an upper three-bridge fault signal; if so, execute step 7; if not, execute step 8; Step 7: The second logic circuit controls the switch tubes of the upper three bridges of the drive control module to be disconnected, and controls the switch tubes of the lower three bridges to be closed; Step 8: The second logic circuit determines whether the second fault signal sent by the drive fault detection module is a lower three-bridge fault signal; if so, execute step 9; if not, execute step 10; Step 9: the second logic circuit controls the switch tubes of the lower three bridges of the drive control module to be disconnected, and the switch tubes of the upper three bridges to be closed; Step 10: the second logic circuit controls the switch tubes of the upper three bridges of the drive control module to be disconnected, and controls the switch tubes of the lower three bridges to be closed; After step 4, it also includes: Step 11: the overvoltage detection module determines whether the motor power supply voltage is restored to a preset range, if so, executing step 12; if not, maintaining the active short circuit state of the active short circuit module; Step 12: The active short-circuit module establishes a connection between the controller and the drive control module, and stops sending an active short-circuit control signal to the drive control module.

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