An electric vehicle and a control circuit of a drive motor thereof

Abstract

The application provides an electric vehicle and a control circuit of a driving motor thereof. The control circuit of the driving motor comprises: a first detection circuit electrically connected with a low-voltage power supply of the electric vehicle, which is used for outputting a first control signal when the low-voltage power supply fails; a second detection circuit electrically connected with the first detection circuit, which is powered by the first detection circuit, and is used for outputting a second control signal when the low-voltage power supply normally supplies power and a torque control logic of a motor controller of the electric vehicle fails; and a control circuit electrically connected with the first detection circuit and the second detection circuit respectively, which is used for controlling the driving motor of the electric vehicle to short circuit according to the first control signal or the second control signal. The scheme of the application improves the passive safety performance of the vehicle.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of new energy vehicles, in particular to an electric vehicle and a control circuit of a driving motor thereof. BACKGROUND

[0002] With the increasing sales of pure electric vehicles year by year, the safety requirements are also getting higher and higher. The motor controller is a very important control unit of the pure electric vehicle, which controls and monitors the working state of the motor in real time to ensure the driving safety of passengers.

[0003] During the driving of the vehicle, unexpected controller failure states may occur. If not handled properly, it may cause vehicle system failure, and even endanger the personal safety of the driver.

[0004] The failure state of the controller can be divided into the following two points:

[0005] 1) Low-voltage power supply failure. The current power supply chip of the motor controller of the new energy vehicle mainly adopts SBC (System Basis Chips), which is an integrated component containing power supply, monitoring and diagnosis, and wake-up functions. Due to its high integration, if the SBC fails, it will cause abnormal power supply of multiple low-voltage power supplies of the motor controller, such as communication power supply, power drive power supply, CPU (central processing unit) power supply, etc., and system control failure.

[0006] 2) When the power supply is normal, torque control logic failure occurs, such as excessive electric drive torque, insufficient electric drive torque, unexpected reverse drive torque, etc. during driving. The above situations are related to control logic algorithms and also pose a great safety hazard to driving safety. SUMMARY

[0007] The technical problem to be solved by the present application is to provide an electric vehicle and a control circuit of a driving motor thereof, which improves the passive safety performance of the electric vehicle.

[0008] To solve the above technical problems, the technical scheme of the present application is as follows:

[0009] A control circuit of a driving motor of an electric vehicle, comprising:

[0010] A first detection circuit electrically connected to a low-voltage power supply of the electric vehicle, configured to output a first control signal when detecting that the low-voltage power supply fails;

[0011] A second detection circuit electrically connected to the first detection circuit, the second detection circuit being powered by the first detection circuit, configured to output a second control signal when the low-voltage power supply is normally powered and the torque control logic of the motor controller of the electric vehicle fails;

[0012] A control circuit electrically connected to the first detection circuit and the second detection circuit respectively, configured to control the drive motor of the electric vehicle to short circuit according to the first control signal or the second control signal.

[0013] Optionally, the first detection circuit comprises:

[0014] A system base chip, an input end of the system base chip being electrically connected to the low-voltage power supply;

[0015] A first transistor switch electrically connected to the low-voltage power supply, the first transistor switch being electrically connected to an output end of the system base chip through a second transistor switch;

[0016] When the system base chip detects that the low-voltage power supply fails, the system base chip outputs a first low-level signal to the second transistor switch, the second transistor switch is turned off, the first transistor switch is turned off, and the control circuit is outputted with the first control signal through the second detection circuit.

[0017] Optionally, the output end of the system base chip comprises a first output end, a second output end and a third output end;

[0018] The first output end is electrically connected to the second transistor switch through a first resistor;

[0019] The second output end is electrically connected to the second transistor switch through a third resistor;

[0020] The second transistor switch is electrically connected to the low-voltage power supply through a second resistor;

[0021] The source of the second transistor switch is electrically connected to the gate of the first transistor switch;

[0022] The third output end is electrically connected to the second detection circuit to power the second detection circuit;

[0023] When the system base chip detects that the low-voltage power supply fails, the first output end outputs a first low-level signal to the second transistor switch.

[0024] Optionally, when the system base chip detects that the low-voltage power supply is supplying power normally, the second output terminal outputs the target voltage to the second transistor switch through the third resistor, the second transistor switch is turned on, the first transistor switch is turned on, and a third control signal is output to the control circuit through the second detection circuit;

[0025] The control circuit controls the drive motor to work normally according to the third control signal.

[0026] Optionally, the second detection circuit includes:

[0027] A central processing unit, wherein the input terminal of the central processing unit is electrically connected to the third output terminal of the system base chip;

[0028] A high-side drive module is electrically connected to the output terminal of the central processing unit and the third output terminal of the system base chip, respectively. The high-side drive module is electrically connected to a power drive power supply, which is electrically connected to the drain of the first transistor switch. The system base chip provides low-voltage power to the high-side drive module through the third output terminal. The power drive power supply provides power to the high-side drive module.

[0029] When the central processing unit detects that the low-voltage power supply is operating normally and the torque control logic of the electric vehicle's motor controller is malfunctioning, it outputs a second low-level signal to the high-side drive module through the output terminal of the central processing unit, causing the high-side drive module to send a second control signal to the control circuit.

[0030] Optionally, when the central processing unit detects that the low-voltage power supply is supplying power normally and the torque control logic of the electric vehicle's motor controller is not faulty, it outputs a high-level signal to the high-side drive module through the output terminal of the central processing unit, so that the high-side drive module sends a fourth control signal to the control circuit.

[0031] The control circuit controls the drive motor to work normally according to the fourth control signal.

[0032] Optionally, the output terminals of the central processing unit include: a first output terminal and a second output terminal;

[0033] The central processing unit outputs the second low-level signal or the high-level signal to the high-side driving module through the first output terminal and the second output terminal.

[0034] Optionally, the control circuit includes:

[0035] The first relay and the second relay are electrically connected to the high-side drive module;

[0036] The first relay is electrically connected to the U-phase, V-phase, and V-phase of the drive motor;

[0037] The second relay is electrically connected to the W and V phases of the drive motor;

[0038] When the first relay and the second relay receive the second control signal sent by the high-side drive module according to the second low-level signal, the first relay and the second relay are controlled to be in a power-off state, and the U, V and W three-phase drive circuits of the drive motor are in a short-circuit state.

[0039] Optionally, both the first relay and the second relay are normally closed relays; when the first relay and the second relay are powered off, their contacts are closed.

[0040] Embodiments of the present invention also provide an electric vehicle, including a control circuit for a drive motor as described above.

[0041] The above-described solution of the present invention has at least the following beneficial effects:

[0042] The above-described solution of the present invention detects a low-voltage power supply fault in the electric vehicle using a first detection circuit and a fault in the torque control logic of the electric vehicle's motor controller using a second detection circuit. Based on the detection results of the first or second detection circuit, the control circuit controls the drive motor of the electric vehicle to short-circuit. This ensures that when the electric vehicle experiences a low-voltage power supply fault or a fault in the torque control logic of the motor controller, the three-phase drive circuit of the drive motor enters a short-circuit state, and the vehicle stops in a limp state. This avoids the risks of sudden acceleration or reverse acceleration due to loss of vehicle control, and improves the passive safety performance of the vehicle. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of the control circuit of the drive motor of the electric vehicle of the present invention;

[0044] Figure 2 This is a schematic diagram of the relay in the control circuit of the drive motor of the electric vehicle of the present invention. Detailed Implementation

[0045] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0046] like Figure 1 As shown, an embodiment of the present invention provides a control circuit for a drive motor of an electric vehicle, comprising:

[0047] The first detection circuit 11, which is electrically connected to the low-voltage power supply KL30 of the electric vehicle, is used to output a first control signal when a fault is detected in the low-voltage power supply.

[0048] A second detection circuit 12 is electrically connected to the first detection circuit 11. The second detection circuit 12 is powered by the first detection circuit 11 and is used to output a second control signal when the low-voltage power supply KL30 is supplying power normally and the torque control logic of the motor controller of the electric vehicle is faulty.

[0049] The control circuit 13, which is electrically connected to the first detection circuit 11 and the second detection circuit 12 respectively, is used to control the drive motor of the electric vehicle to short-circuit according to the first control signal or the second control signal.

[0050] In this embodiment, the motor controller is a core control system used to control the operation of the motor. It controls the motor to work according to set directions, speeds, angles, response times, etc. In pure electric vehicles, the function of the motor controller is to convert the electrical energy stored in the power battery into the electrical energy required to drive the motor according to commands such as gear position, throttle, and brake, thereby controlling the starting operation, forward and reverse speed, climbing force, and other driving states of the pure electric vehicle. It is one of the key components of electric vehicles.

[0051] The KL30 low-voltage power supply is used to power the low-voltage batteries of pure electric vehicles, with a power supply voltage range of 9V to 16V.

[0052] This embodiment uses a first detection circuit to detect low-voltage power supply failures in the electric vehicle and a second detection circuit to detect faults in the torque control logic of the electric vehicle's motor controller. Based on the detection results of the first or second detection circuit, the control circuit controls the drive motor of the electric vehicle to short-circuit. This ensures that when the electric vehicle experiences a low-voltage power supply failure or a fault in the torque control logic of the motor controller, the three-phase drive circuit of the drive motor enters a short-circuit state, and the vehicle stops in a limp state. This avoids the risks of sudden acceleration or reverse acceleration due to loss of vehicle control, thus improving the passive safety performance of the vehicle.

[0053] In an optional embodiment of the present invention, the first detection circuit 11 includes:

[0054] The system base chip SBC, the input terminal of which is electrically connected to the low-voltage power supply KL30;

[0055] A first transistor switch Q1 is electrically connected to the low-voltage power supply KL30, and the first transistor switch Q1 is electrically connected to the output terminal of the system base chip SBC through a second transistor switch Q2.

[0056] When the system base chip SBC detects a fault in the low-voltage power supply KL30, it outputs a first low-level signal to the second transistor switch Q2, turning off the second transistor switch Q2 and the first transistor switch Q1, and outputs a first control signal to the control circuit 13 through the second detection circuit 12.

[0057] In this embodiment, the system base chip SBC is an independent chip that includes power supply, communication, monitoring and diagnostics, security monitoring, and switching control. The power supply module of the chip can be a linear power supply or a switching power supply. Communication includes CAN, CANFD, and other communication methods. Monitoring and diagnostics include wake-up input, watchdog timer, reset, interrupt, and failure output after circuit diagnosis.

[0058] In this embodiment, the circuit fault diagnosis function of SBC is used. When faults such as abnormal chip reset, low output voltage value, or high output voltage value occur, the control output pin of the chip will output a low level signal. The level change of this pin is used to control this safety protection system.

[0059] In this embodiment, when the low-voltage power supply KL30 fails, a first low-level signal is output to the second transistor switch Q2 when the fault is detected. The second transistor switch Q2 is turned off, the first transistor switch Q1 is turned off, and a first control signal is output to the control circuit 13 through the second detection circuit 12. This causes the control circuit 13 to control the drive motor to short-circuit according to the first control signal, and the vehicle stops in a limp state. This avoids the risk of sudden acceleration or reverse acceleration due to loss of vehicle control, and improves the passive safety performance of the vehicle.

[0060] In an optional embodiment of the present invention, the output terminals of the system base chip SBC include: a first output terminal S1, a second output terminal S2, and a third output terminal S3;

[0061] The first output terminal S1 is electrically connected to the second transistor switch Q2 through the first resistor R1;

[0062] The second output terminal S2 is electrically connected to the second transistor switch Q2 through the third resistor R3;

[0063] The second transistor switch Q2 is electrically connected to the low-voltage power supply KL30 through the second resistor R2;

[0064] The source of the second transistor switch Q2 is electrically connected to the gate of the first transistor switch Q1;

[0065] The third output terminal S3 is electrically connected to the second detection circuit 12 and supplies power to the second detection circuit.

[0066] When the system base chip SBC detects a fault in the low-voltage power supply KL30, the first output terminal S1 outputs a low-level signal to the second transistor switch Q2.

[0067] In this embodiment, the system base chip SBC provides low-voltage power supplies such as 3.3V and 5V to the motor controller, powering the high-side drive module and CPU, ensuring the normal operation of the system. Simultaneously, it monitors the fault status of each low-voltage power supply. When the SBC diagnoses a fault in the low-voltage power supply KL30, it outputs a low-level signal through its first output pin S1 to turn off Q2. After Q2 is turned off, pin 1 of Q1 changes from low to high, turning off Q1. This outputs a first control signal to the control circuit 13, causing the control circuit 13 to short-circuit the drive motor according to the first control signal. The vehicle stops in a limp state, avoiding the risks of sudden acceleration or reverse acceleration due to loss of vehicle control, thus improving the vehicle's passive safety performance.

[0068] Both the first transistor switch Q1 and the second transistor switch Q2 are MOSFETs, or Metal-Oxide-Semiconductor Field-Effect Transistors, which are widely used in analog and digital circuits. They can be divided into N-type and P-type types, commonly referred to as NMOSFETs and PMOSFETs, respectively. Other abbreviations include NMOS and PMOS. In this embodiment, Q2 is an NMOS and Q1 is a PMOS, and they function as switchers between the on and off states of the circuit.

[0069] In an optional embodiment of the present invention, when the system base chip SBC detects that the low-voltage power supply KL30 is supplying power normally, the second output terminal S2 outputs a target voltage to the second transistor switch Q2 through the third resistor (R3), the second transistor switch Q2 is turned on, the first transistor switch Q1 is turned on, and a third control signal is output to the control circuit 13 through the second detection circuit 12; the control circuit 13 controls the drive motor to work normally according to the third control signal.

[0070] In an optional embodiment of the present invention, the second detection circuit 12 includes:

[0071] The central processing unit (CPU) is electrically connected to the third output terminal S3 of the system base chip (SBC).

[0072] A high-side drive module U1 is electrically connected to the output terminal of the central processing unit (CPU) and the third output terminal S3 of the system base chip (SBC). The high-side drive module U1 is electrically connected to a power drive power supply KL30-1, which is electrically connected to the drain of the first transistor switch Q1. The system base chip (SBC) provides low-voltage power to the high-side drive module U1 through the third output terminal S3. The power drive power supply KL30-1 provides power to the high-side drive module U1.

[0073] When the central processing unit (CPU) detects that the low-voltage power supply KL30 is supplying power normally and the torque control logic of the electric vehicle's motor controller is malfunctioning, the CPU outputs a second low-level signal to the high-side drive module U1 through its output terminal, causing the high-side drive module U1 to send a second control signal to the control circuit.

[0074] In this embodiment, in the high-side drive module U1, "high-side" refers to the power supply terminal or the +Vcc / Vdd terminal of the load. A high-side driver is a driver whose switching element is located between Vcc and the load. The power drive power supply KL30-1 is the power drive power supply for the high-side drive module U1.

[0075] In the above embodiments of the present invention, when the first transistor switch Q1 is turned off, the power drive power supply KL30-1 is also turned off, thereby outputting a second control signal to the control circuit 13 through the high-side drive module U1, so that the control circuit 13 controls the drive motor to short-circuit according to the first control signal, and the vehicle stops in a limp state, avoiding the risk of sudden acceleration or reverse acceleration due to loss of vehicle control, and improving the passive safety performance of the car.

[0076] Similarly, when the first transistor switch Q1 is turned on, the power drive power supply KL30-1 is in normal power supply state, thereby outputting the third control signal to the control circuit 13 through the high-side drive module U1, so that the control circuit 13 controls the drive motor to work normally according to the third control signal.

[0077] When the central processing unit (CPU) detects that the low-voltage power supply KL30 is supplying power normally and the torque control logic of the electric vehicle's motor controller is faulty, the CPU outputs a second low-level signal to the high-side drive module U1 through its output terminal. This causes the high-side drive module U1 to send a second control signal to the control circuit 13, which then controls the drive motor to short-circuit according to the second control signal. The vehicle stops in a limp state, avoiding the risks of sudden acceleration or reverse acceleration due to loss of vehicle control, thus improving the vehicle's passive safety performance.

[0078] In an optional embodiment of the present invention, when the central processing unit (CPU) detects that the low-voltage power supply KL30 is supplying power normally and the torque control logic of the electric vehicle's motor controller is not faulty, the CPU outputs a high-level signal to the high-side drive module U1 through the output terminal of the CPU, so that the high-side drive module U1 sends a fourth control signal to the control circuit.

[0079] The control circuit 13 controls the drive motor to work normally according to the fourth control signal.

[0080] Similarly, when the central processing unit (CPU) detects that the low-voltage power supply KL30 is supplying power normally and the torque control logic of the electric vehicle's motor controller is not faulty, the CPU outputs a high-level signal to the high-side drive module U1 through its output terminal. The high-side drive module U1 then outputs a fourth control signal to the control circuit 13, causing the control circuit 13 to control the drive motor to work normally according to the fourth control signal.

[0081] In an optional embodiment of the present invention, the output terminal of the central processing unit (CPU) includes: a first output terminal C1 and a second output terminal C2;

[0082] The central processing unit (CPU) outputs the second low-level signal or the high-level signal to the high-side driver module U1 through the first output terminal C1 and the second output terminal C2.

[0083] In this embodiment, the CPU control output is divided into two signals: CPU control output 1 and CPU control output 2, which respectively control the relay control 1 of the first relay J1 and the relay control 2 of the second relay J2 to enter the enable and disable states.

[0084] During normal operation, this pin outputs a high level to enable the relay control function. When the CPU detects a fault, this pin outputs a low level to disable the relay control function.

[0085] In an optional embodiment of the present invention, the control circuit 13 includes:

[0086] The first relay J1 and the second relay J2 are electrically connected to the high-side drive module U1;

[0087] The first relay J1 is electrically connected to the U phase, V phase, and V phase of the drive motor;

[0088] The second relay is electrically connected to the W and V phases of the drive motor;

[0089] When the first relay J1 and the second relay J2 receive the second control signal sent by the high-side drive module U1, they are energized, and the U, V, and W phase drive circuits of the drive motor are short-circuited. The vehicle stops in a limp-like state, avoiding the risks of sudden acceleration or reverse acceleration due to loss of vehicle control, thus improving the vehicle's passive safety performance.

[0090] In an optional embodiment of the present invention, both the first relay J1 and the second relay J2 are normally closed relays; when the first relay and the second relay are powered off, their contacts are closed.

[0091] A relay is an electronic control device. It has a control system, also known as the input circuit (the circuit containing terminals "1" and "2" in the diagram below), and a controlled system, also known as the output circuit (the circuit containing terminals "3" and "4" in the diagram below). It is usually used in automatic control circuits. It is an "automatic switch" that uses a small current to control a larger current. It plays a role in automatic control and circuit switching in the circuit.

[0092] like Figure 2 As shown, a normally closed relay: normally closed refers to the contacts... Figure 2 Terminals "3" and "4" are the two contacts of the relay in the natural, unenergized state. If both contacts are conductive, it is called normally closed (NC). A normally closed contact is a contact that is closed in the normal (unenergized) state and will open when the coil is energized.

[0093] In this embodiment, the CPU is the core control unit of the motor controller, which controls all information processing and program execution. This mainly includes controlling timing, processing data, and executing operations, such as collecting sensor information on the gear position, throttle, and brakes of the electric vehicle, while simultaneously driving and controlling external loads such as relays.

[0094] In this embodiment, the drive motor is a permanent magnet synchronous motor, which is an important power supply unit for pure electric vehicles and is used to drive the vehicle to move according to control commands.

[0095] The working principle of the above embodiments of the present invention is as follows:

[0096] The low-voltage power supply KL30 provides low-voltage power to the battery of pure electric vehicles, and provides power input to the system base chip SBC and the power drive power supply KL30-1 respectively.

[0097] SBC converts the voltage to 3.3V and 5V through its internal voltage conversion circuit. The 3.3V output is pulled up to the control pin of Q2 through resistor R3. When the system is working normally, the control pin of Q2 is pulled up to 3.3V, Q2 is in the on state, pin 1 of Q1 is low level, Q1 is on, and KL30 provides power to the high-side drive module U1 through the first transistor switch Q1.

[0098] When a fault is detected, the SBC control output can turn off Q2 by outputting a low level, thereby turning off Q1.

[0099] The high-side drive module U1 is powered by two power supplies. The first power supply is 5V, provided by the third output terminal S3 of the SBC, which powers the internal chip of the high-side drive module U1 to ensure the normal operation of the chip. The second power supply is provided by KL30-1, which is the power drive power supply for the first relay J1 and the second relay J2. The drive output of the first relay J1 and the second relay J2 is provided through the internal switching circuit of U1. The two signals of relay control 1 and relay control 2 are controlled by the two signals of CPU control output 1 and CPU control output 2 respectively. When the two signals of CPU control output 1 and CPU control output 2 are high, the two signals of relay control 1 and relay control 2 drive the output enable, and the first relay J1 and the second relay J2 are in the power-on working state.

[0100] When both CPU control output 1 and CPU control output 2 are at a low level, the relay control 1 and relay control 2 signals drive the output enable to turn off, the relay is powered down, and it is in a non-working state.

[0101] The first relay J1 and the second relay J2 are controlled by two signals, relay control 1 and relay control 2, respectively. When the two signals, relay control 1 and relay control 2, output drive enable signals, the first relay J1 and the second relay J2 start to work. Since the relays used are normally closed relays, their contacts are open when the relays are working. At this time, the U, V and W three-phase drive circuits of the permanent magnet synchronous motor are open, and the vehicle drives normally.

[0102] When relay control 1 and relay control 2 do not output drive enable signals, the first relay J1 and the second relay J2 stop working. Since the relays used are normally closed, their contacts are closed when the relays are not working. At this time, the U, V and W three-phase drive circuits of the permanent magnet synchronous motor are short-circuited, triggering the safety protection mechanism of the motor controller. The vehicle enters a limp state, reminding the driver to leave the vehicle as soon as possible.

[0103] In the above embodiments of the present invention, KL30 provides power input to SBC and KL30-1 respectively. SBC outputs 3.3V and 5V power to power the high-side drive module U1 and the CPU, ensuring normal system operation. The high-side drive module U1 outputs two drive signals, relay control 1 and relay control 2. The first relay J1 and the second relay J2, two normally closed relays, are powered on and their contacts are open. The U, V and W three-phase drive circuits of the permanent magnet synchronous motor are in an open circuit state, and the vehicle drives normally.

[0104] When a fault occurs, it is described in three fault states:

[0105] 1) Operating state when low-voltage power supply fails: When the low-voltage power supply fails, since the SBC itself has a fault diagnosis function, the SBC control output is low level, which controls the second transistor switch Q2 (MOSFET) to operate. Q2 changes from the on state to the off state, and at the same time, pin 1 of Q1 changes from low level to high level, and Q1 is turned off.

[0106] After Q1 is turned off, KL30-1 loses power. Since KL30-1 supplies power to the high-side drive module U1, the two relay drive signals, relay control 1 and relay control 2, disappear after Q1 is turned off. The first relay J1 and the second relay J2 change from working state to non-working state.

[0107] Because the two contacts of the first relay J1 and the second relay J2 are closed when they are not in operation, the U-phase and V-phase, and V-phase and W-phase drive circuits of the drive motor enter a short circuit state, and the vehicle enters a limp state, reminding the driver to stop the vehicle as soon as possible.

[0108] 2) Operating state when the low-voltage power supply fails completely: When the low-voltage power supply fails completely, even in the most extreme case where all low-voltage power supplies are interrupted, KL30-1 loses power, causing the power supply to the high-side drive module U1 to fail, and the first relay J1 and the second relay J2 are in a non-operating state.

[0109] Since the first relay J1 and the second relay J2 are not in operation and their two contacts are closed, similarly, the U-phase and V-phase, and V-phase and W-phase drive circuits of the motor enter a short-circuit state, and the vehicle enters a limp state.

[0110] Here, normally closed relays are used to ensure that even in the event of a low-voltage power supply failure, a complete power supply failure, or a torque control logic failure, the U-phase and V-phase, and V-phase and W-phase drive circuits of the motor can still enter a short-circuit state respectively.

[0111] 3) Working state when the low voltage power supply is working normally and a control logic fault occurs: When the low voltage power supply is normal and the torque control logic of the controller fails, the CPU control output 1 and CPU control output 2 change from high level to low level, shut down the drive output of relay control 1 and relay control 2, and the relay changes from working state to non-working state.

[0112] Similarly, the U-phase and V-phase, and V-phase and W-phase drive circuits of the motor enter a short-circuit state, and the vehicle enters a limp state.

[0113] Alternatively, the upper or lower bridge arm of the U, V, and W phases can be short-circuited by controlling the IGBT (Insulated Gate Bipolar Transistor) circuit of the motor controller to achieve a safety protection function. However, this solution can only be implemented when the low-voltage power supply of the controller is working normally. If the low-voltage power supply fails, the safety protection function cannot be achieved.

[0114] Embodiments of the present invention also provide an electric vehicle, including a control circuit for a drive motor as described above. All implementations of the above control circuit are applicable to embodiments of this electric vehicle and achieve the same technical effects. The above embodiments of the present invention, by diagnosing potential risks in both the hardware and software of the motor controller, greatly improve the passive safety performance of the vehicle. They enable protection functions even in the event of a low-voltage power failure in the controller, reminding the driver to stop the vehicle immediately and ensuring personal safety.

[0115] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A control circuit for a drive motor of an electric vehicle, characterized in that, include: A first detection circuit (11) electrically connected to the low-voltage power supply (KL30) of the electric vehicle is used to output a first control signal when a fault is detected in the low-voltage power supply (KL30); A second detection circuit (12) electrically connected to the first detection circuit (11), the second detection circuit (12) being powered by the first detection circuit (11), is used to output a second control signal when the low-voltage power supply (KL30) is normally powered and the torque control logic of the motor controller of the electric vehicle malfunctions; A control circuit (13) electrically connected to the first detection circuit (11) and the second detection circuit (12) respectively is used to control the drive motor of the electric vehicle to short-circuit according to the first control signal or the second control signal; The first detection circuit (11) includes: The system base chip SBC, the input terminal of which is electrically connected to the low-voltage power supply (KL30); A first transistor switch (Q1) is electrically connected to the low-voltage power supply (KL30), and the first transistor switch (Q1) is electrically connected to the output terminal of the system base chip SBC through a second transistor switch (Q2); The output terminals of the system base chip SBC include: a first output terminal (S1), a second output terminal (S2), and a third output terminal (S3); The first output terminal (S1) is electrically connected to the second transistor switch (Q2) through the first resistor (R1); The second output terminal (S2) is electrically connected to the second transistor switch (Q2) through the third resistor (R3); The second transistor switch (Q2) is electrically connected to the low-voltage power supply (KL30) through the second resistor (R2); The source of the second transistor switch (Q2) is electrically connected to the gate of the first transistor switch (Q1); The third output terminal (S3) is electrically connected to the second detection circuit (12) to supply power to the second detection circuit (12); When the system base chip SBC detects a fault in the low-voltage power supply (KL30), the first output terminal (S1) outputs a first low-level signal to the second transistor switch (Q2), the second transistor switch (Q2) turns off, the first transistor switch (Q1) turns off, and the second detection circuit (12) outputs a first control signal to the control circuit (13).

2. The control circuit for the drive motor of an electric vehicle according to claim 1, characterized in that, When the system base chip SBC detects that the low-voltage power supply (KL30) is supplying power normally, the second output terminal (S2) outputs the target voltage to the second transistor switch (Q2) through the third resistor (R3). The second transistor switch (Q2) is turned on, the first transistor switch (Q1) is turned on, and the third control signal is output to the control circuit (13) through the second detection circuit (12). The control circuit (13) controls the drive motor to work normally according to the third control signal.

3. The control circuit for the drive motor of an electric vehicle according to claim 1, characterized in that, The second detection circuit (12) includes: A central processing unit (CPU) is electrically connected to the third output terminal (S3) of the system base chip (SBC). A high-side drive module (U1) is electrically connected to the output terminal of the central processing unit (CPU) and the third output terminal (S3) of the system base chip (SBC). The high-side drive module (U1) is electrically connected to the power drive power supply (KL30-1), and the power drive power supply (KL30-1) is electrically connected to the drain of the first transistor switch (Q1). The system base chip SBC provides low-voltage power to the high-side drive module (U1) through the third output terminal (S3); The power drive power supply (KL30-1) provides power to the high-side drive module (U1); When the central processing unit (CPU) detects that the low-voltage power supply (KL30) is supplying power normally and the torque control logic of the electric vehicle's motor controller is malfunctioning, it outputs a second low-level signal to the high-side drive module (U1) through the CPU's output terminal, causing the high-side drive module (U1) to send a second control signal to the control circuit.

4. The control circuit for the drive motor of an electric vehicle according to claim 3, characterized in that, When the central processing unit (CPU) detects that the low-voltage power supply (KL30) is supplying power normally and that the torque control logic of the electric vehicle's motor controller is not faulty, it outputs a high-level signal to the high-side drive module (U1) through the output terminal of the CPU, so that the high-side drive module (U1) sends a fourth control signal to the control circuit. The control circuit (13) controls the drive motor to work normally according to the fourth control signal.

5. The control circuit for the drive motor of an electric vehicle according to claim 4, characterized in that, The output terminals of the central processing unit (CPU) include: a first output terminal (C1) and a second output terminal (C2); The central processing unit (CPU) outputs the second low-level signal or the high-level signal to the high-side driver module (U1) through the first output terminal (C1) and the second output terminal (C2).

6. The control circuit for the drive motor of an electric vehicle according to claim 5, characterized in that, The control circuit includes: The first relay (J1) and the second relay (J2) are electrically connected to the high-side drive module (U1); The first relay (J1) is electrically connected to the U-phase and V-phase of the drive motor; The second relay (J2) is electrically connected to the W phase and V phase of the drive motor; When the first relay (J1) and the second relay (J2) receive the second control signal sent by the high-side drive module (U1) according to the second low-level signal, they control the first relay (J1) and the second relay (J2) to be in a power-off state, and the U, V and W three-phase drive circuits of the drive motor are in a short-circuit state.

7. The control circuit for the drive motor of an electric vehicle according to claim 6, characterized in that, Both the first relay (J1) and the second relay (J2) are normally closed relays; when the first relay (J1) and the second relay (J2) are powered off, their contacts are closed.

8. An electric vehicle, characterized in that, It includes the control circuit for the drive motor as described in any one of claims 1 to 7.

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