CN116061705A - Electric automobile and control circuit of driving motor thereof - Google Patents

Abstract

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

Description

Electric automobile and control circuit of driving motor thereof

Technical Field

The invention relates to the technical field of new energy automobiles, in particular to an electric automobile and a control circuit of a driving motor of the electric automobile.

Background

With the increase of sales of the pure electric vehicles year by year, the safety requirements of the pure electric vehicles are higher and higher, and the motor controller is an important control unit of the pure electric vehicles, controls and monitors the working state of the motor in real time, so that the driving safety of passengers is ensured.

During the running process of the vehicle, unexpected controller fault states can occur, if the control states are incorrectly processed, the faults of the whole vehicle system can be caused, and even the risks are brought to the personal safety of a driver.

The fault state of the controller can be divided into two points:

1) The power supply chip of the motor controller of the current new energy automobile mainly adopts an SBC (System Basis Chips, system base chip) which is an integrated component and comprises the functions of power supply, monitoring diagnosis, awakening and the like, and if the SBC fails, the power supply abnormality of a plurality of low-voltage power supplies of the motor controller, such as a communication power supply, a power driving power supply, a CPU (central processing unit, a central processing unit) power supply and the like, is caused because of higher integration level, and the system control fails.

2) When the power supply is normal, a torque control logic fault occurs, such as the situations of overlarge electric drive torque, unexpected reverse drive torque and the like in the running process, and the situations are related to a control logic algorithm, so that great potential safety hazards are brought to running safety.

Disclosure of Invention

The invention aims to solve the technical problem of providing an electric automobile and a control circuit of a driving motor thereof, which improve the passive safety performance of the electric automobile.

In order to solve the technical problems, the technical scheme of the invention is as follows:

a control circuit of a driving motor of an electric vehicle, comprising:

the first detection circuit is electrically connected with a low-voltage power supply of the electric automobile and is used for outputting a first control signal when detecting the fault of the low-voltage power supply;

the second detection circuit is electrically connected with the first detection circuit, is powered by the first detection circuit and is used for outputting a second control signal when the low-voltage power supply supplies power normally and the torque control logic of the motor controller of the electric automobile fails;

and the control circuit is electrically connected with the first detection circuit and the second detection circuit respectively and is used for controlling the driving motor of the electric automobile to be in short circuit according to the first control signal or the second control signal.

Optionally, the first detection circuit includes:

the input end of the system basic chip is electrically connected with the low-voltage power supply;

the first transistor switch is electrically connected with the low-voltage power supply, and is electrically connected with the output end of the system base chip through the second transistor switch;

when the system base chip detects the low-voltage power supply fault, a first low-level signal is output to the second transistor switch, the second transistor switch is turned off, the first transistor switch is turned off, and a first control signal is output to the control circuit through the second detection circuit.

Optionally, the output end of the system base chip includes: the first output end, the second output end and the third output end;

the first output end is electrically connected with the second transistor switch through a first resistor;

the second output end is electrically connected with the second transistor switch through a third resistor;

the second transistor switch is electrically connected with the low-voltage power supply through a second resistor;

the source electrode of the second transistor switch is electrically connected with the gate electrode of the first transistor switch;

the third output end is electrically connected with the second detection circuit and supplies power for the second detection circuit;

when the system base chip detects the low-voltage power supply fault, the first output end outputs a first low-level signal to the second transistor switch.

Optionally, when the system base chip detects that the low-voltage power supply supplies power normally, the second output end outputs a 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;

and the control circuit controls the driving motor to work normally according to the third control signal.

Optionally, the second detection circuit includes:

the input end of the central processing unit is electrically connected with the third output end of the system basic chip;

the high-side driving module is electrically connected with the output end of the central processing unit and the third output end of the system basic chip respectively, and is electrically connected with a power driving power supply which is electrically connected with the drain electrode of the first transistor switch; the system basic chip provides a low-voltage power supply for the high-side driving module through the third output end; the power driving power supply provides power supply for the high-side driving module;

when the central processing unit detects that the low-voltage power supply supplies power normally and the torque control logic of the motor controller of the electric automobile fails, a second low-level signal is output to the high-side driving module through the output end of the central processing unit, so that the high-side driving module sends a second control signal to the control circuit.

Optionally, when the central processing unit detects that the low-voltage power supply supplies power normally and the torque control logic of the motor controller of the electric automobile has no fault, the output end of the central processing unit outputs a high-level signal to the high-side driving module, so that the high-side driving module sends a fourth control signal to the control circuit;

and the control circuit controls the driving motor to work normally according to the fourth control signal.

Optionally, the output end of the central processing unit includes: a first output terminal and a second output terminal;

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 end and the second output end.

Optionally, the control circuit includes:

the first relay and the second relay are electrically connected with the high-side driving module;

the first relay is electrically connected with a U phase, a V phase and a V phase of the driving motor;

the second relay is electrically connected with a W phase and a V phase of the driving motor;

when the first relay and the second relay receive a second control signal sent by the high-side driving module according to the second low-level signal, the first relay and the second relay are controlled to be in a power-down state, and a U, V, W three-phase driving loop of the driving motor is in a short-circuit state.

Optionally, the first relay and the second relay are both normally closed relays; and under the power-down state of the first relay and the second relay, the contacts are in a closed state.

The embodiment of the invention also provides an electric automobile, which comprises the control circuit of the driving motor.

The scheme of the invention at least comprises the following beneficial effects:

according to the scheme, the first detection circuit is used for detecting the fault of the low-voltage power supply of the electric automobile, the second detection circuit is used for detecting the fault of the torque control logic of the motor controller of the electric automobile, and the control circuit is used for controlling the driving motor of the electric automobile to be in short circuit according to the detection result of the first detection circuit or the second detection circuit, so that when the fault of the low-voltage power supply of the electric automobile or the fault of the torque control logic of the motor controller occurs, the three-phase driving circuit of the driving motor can be ensured to enter a short circuit state, the automobile stops in a limp state, the risks of sudden acceleration or reverse acceleration and the like caused by the out-of-control of the automobile are avoided, and the passive safety performance of the automobile is improved.

Drawings

Fig. 1 is a schematic diagram of a control circuit of a driving motor of an electric vehicle according to the present invention;

fig. 2 is a schematic diagram of a relay of a control circuit of a driving motor of an electric vehicle according to the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below 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 embodied 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.

As shown in fig. 1, an embodiment of the present invention provides a control circuit for a driving motor of an electric vehicle, including:

the first detection circuit 11 is electrically connected with a low-voltage power supply KL30 of the electric automobile and is used for outputting a first control signal when detecting the fault of the low-voltage power supply;

a second detection circuit 12 electrically connected to the first detection circuit 11, where the second detection circuit 12 is powered by the first detection circuit 11 and is configured to output a second control signal when the low-voltage power supply KL30 supplies power normally and a torque control logic of a motor controller of the electric automobile fails;

and a control circuit 13 electrically connected to the first detection circuit 11 and the second detection circuit 12, respectively, for controlling the driving motor of the electric vehicle to be short-circuited according to the first control signal or the second control signal.

In this embodiment, the motor controller is a core control system for controlling the operation of the motor, which controls the motor to operate in a set direction, speed, angle, response time, etc. In a pure electric vehicle, a motor controller has the function of converting electric energy stored in a power battery into electric energy required by a driving motor according to instructions such as gears, throttle, brake and the like to control running states such as starting running, advancing and retreating speed, climbing force and the like of the pure electric vehicle, and is one of key parts of the electric vehicle.

The low-voltage power supply KL30 is a low-voltage storage battery power supply of the pure electric vehicle, and the power supply voltage range is generally 9V to 16V.

According to the embodiment, the first detection circuit is used for detecting the fault of the low-voltage power supply of the electric automobile, the second detection circuit is used for detecting the fault of the torque control logic of the motor controller of the electric automobile, and the control circuit is used for controlling the driving motor of the electric automobile to be short-circuited according to the detection result of the first detection circuit or the second detection circuit.

In an alternative embodiment of the present invention, the first detection circuit 11 includes:

the system base chip SBC, the input end of the system base chip SBC is electrically connected with the low-voltage power supply KL 30;

the first transistor switch Q1 is electrically connected with the low-voltage power supply KL30, and the first transistor switch Q1 is electrically connected with the output end of the system basic chip SBC through the second transistor switch Q2;

when the system base chip SBC detects that the low-voltage power supply KL30 fails, a first low-level signal is output to the second transistor switch Q2, 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.

In this embodiment, the system base chip SBC is an independent chip that includes features such as power supply, communication, monitoring and diagnosis, security monitoring, and switching control. The power supply module of the chip CAN be a linear power supply or a switching power supply, the communication comprises communication modes such as CAN, CANFD and the like, and the monitoring diagnosis comprises wake-up input, watchdog, reset and interrupt and failure output after circuit diagnosis.

In this embodiment, the circuit fault diagnosis function of SBC is adopted, and if a fault such as abnormal reset of the chip, low output voltage value, high output voltage value occurs, the control output pin of the chip outputs a low-level signal, and the level change of the pin is applied to control the safety protection system.

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 failure of the low-voltage power supply KL30 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, so that the control circuit 13 controls the driving motor to short circuit according to the first control signal, the vehicle stops in a limp-home state, risks such as rapid acceleration or reverse acceleration due to out-of-control of the vehicle are avoided, and the passive safety performance of the vehicle is improved.

In an alternative embodiment of the present invention, the output terminal of the system base chip SBC includes: a first output terminal S1, a second output terminal S2, and a third output terminal S3;

the first output end S1 is electrically connected with the second transistor switch Q2 through a first resistor R1;

the second output end S2 is electrically connected with the second transistor switch Q2 through a third resistor R3;

the second transistor switch Q2 is electrically connected with the low-voltage power supply KL30 through a second resistor R2;

the source electrode of the second transistor switch Q2 is electrically connected with the gate electrode of the first transistor switch Q1;

the third output end S3 is electrically connected to the second detection circuit 12, and supplies power to the second detection circuit;

when the system base chip SBC detects that the low-voltage power supply KL30 fails, the first output terminal S1 outputs a low-level signal to the second transistor switch Q2.

In this embodiment, the system basic chip SBC is configured to provide low-voltage power sources such as 3.3V and 5V for the motor controller, power the high-side driving module and the CPU, and other module circuits, so as to ensure normal operation of the system, monitor a fault state of each low-voltage power source of the power source, and output a low-level signal through a pin of a first output terminal S1 when the SBC diagnoses that a fault occurs in the low-voltage power source KL30, turn off Q2, and change a pin 1 of Q1 from a low level to a high level after Q2 is turned off, so that Q1 is turned off, and output a first control signal to the control circuit 13, so that the control circuit 13 controls the driving motor to short circuit according to the first control signal, and the vehicle stops in a limp state, thereby avoiding risks such as rapid acceleration or reverse acceleration due to out-of-control of the vehicle, and improving passive safety performance of the vehicle.

The first transistor switch Q1 and the second transistor switch Q2 are MOSFETs, i.e., metal-oxide semiconductor field effect transistors, which are field effect transistors widely used in analog circuits and digital circuits, and may be divided into N-type and P-type types, which are commonly referred to as NMOSFETs and PMOSFETs, and other abbreviations include NMOS, PMOS, and the like. In this embodiment, Q2 is NMOS, and Q1 is PMOS, which plays roles in switching on and off states of the circuit.

In an alternative embodiment of the present invention, when the system base chip SBC detects that the low voltage power supply KL30 supplies 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 driving motor to work normally according to the third control signal.

In an alternative embodiment of the present invention, the second detection circuit 12 includes:

the input end of the Central Processing Unit (CPU) is electrically connected with the third output end S3 of the System Basic Chip (SBC);

the high-side driving module U1 is electrically connected with the output end of the CPU and the third output end S3 of the system basic chip SBC respectively, the high-side driving module U1 is electrically connected with the power driving power supply KL30-1, and the power driving power supply KL30-1 is electrically connected with the drain electrode of the first transistor switch Q1; the system basic chip SBC provides a low-voltage power supply for the high-side driving module U1 through the third output end S3; the power driving power supply KL30-1 provides power supply for the high-side driving module U1;

when the Central Processing Unit (CPU) detects that the low-voltage power supply KL30 supplies power normally and the torque control logic of the motor controller of the electric automobile fails, a second low-level signal is output to the high-side driving module U1 through the output end of the CPU, so that the high-side driving module U1 sends a second control signal to the control circuit.

In this embodiment, the high side of the high side driving module U1 refers to the +Vcc/Vdd terminal of the power source terminal or load. The high side driver is a driver with switching elements between Vcc and the load. The power driving power supply KL30-1 is a power driving power supply of the high-side driving module U1.

In the above embodiment of the present invention, when the first transistor switch Q1 is turned off, the power driving power KL30-1 is also turned off, so that the control circuit 13 outputs a second control signal to the control circuit 13 through the high-side driving module U1, so that the control circuit 13 controls the driving motor to short circuit according to the first control signal, and the vehicle stops in a limp state, thereby avoiding the risk of rapid acceleration or reverse acceleration due to the out-of-control of the vehicle, and improving the passive safety performance of the vehicle;

similarly, when the first transistor switch Q1 is turned on, the power driving power KL30-1 is in a normal power supply state, so that a third control signal is output to the control circuit 13 through the high-side driving module U1, and the control circuit 13 controls the driving motor to work normally according to the third control signal;

when the Central Processing Unit (CPU) detects that the low-voltage power supply KL30 supplies power normally and the torque control logic of the motor controller of the electric automobile fails, the output end of the CPU outputs a second low-level signal to the high-side driving module U1, so that the high-side driving module U1 sends a second control signal to the control circuit 13, the control circuit 13 controls the driving motor to short circuit according to the second control signal, the vehicle stops in a limp state, risks such as rapid acceleration or reverse acceleration caused by out-of-control of the vehicle are avoided, and the passive safety performance of the automobile is improved.

In an optional embodiment of the present invention, when the CPU detects that the low-voltage power KL30 supplies power normally and the torque control logic of the motor controller of the electric vehicle has no fault, the CPU outputs a high-level signal to the high-side driving module U1 through the output end of the CPU, so that the high-side driving module U1 sends a fourth control signal to the control circuit;

the control circuit 13 controls the driving motor to work normally according to the fourth control signal.

Similarly, when the central processing unit CPU detects that the low-voltage power supply KL30 supplies power normally and the torque control logic of the motor controller of the electric automobile has no fault, the high-level signal is output to the high-side driving module U1 through the output end of the central processing unit CPU, and the fourth control signal is output to the control circuit 13 through the high-side driving module U1, so that the control circuit 13 controls the driving motor to work normally according to the fourth control signal.

In an alternative 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;

the central processing unit CPU outputs the second low-level signal or the high-level signal to the high-side driving module U1 through the first output terminal C1 and the second output terminal C2.

In this embodiment, the CPU control output is divided into two signals, i.e., 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 enabled and disabled states.

The pin outputs high level in normal working state for enabling relay control function, and the pin outputs low level when CPU recognizes fault state, and closes relay control function.

In an alternative embodiment of the present invention, the control circuit 13 includes:

a first relay J1 and a second relay J2 electrically connected with the high-side driving module U1;

the first relay J1 is electrically connected with a U phase, a V phase and a V phase of the driving motor;

the second relay is electrically connected with a W phase and a V phase of the driving motor;

when the first relay J1 and the second relay J2 receive the second control signal sent by the high-side driving module U1, the first relay J1 and the second relay J2 are controlled to be in a power-down state, and a U, V, W three-phase driving loop of the driving motor is in a short-circuit state. The vehicle is parked in a limp state, so that risks of sudden acceleration or reverse acceleration and the like caused by out-of-control of the vehicle are avoided, and the passive safety performance of the automobile is improved.

In an alternative embodiment of the present invention, the first relay J1 and the second relay J2 are both normally closed relays; and under the power-down state of the first relay and the second relay, the contacts are in a closed state.

The relay is an electronic control device, which is provided with a control system, namely an input loop, a loop where the ends of 1 and 2 in the lower diagram are positioned and a loop where the ends of 3 and 4 in the lower diagram are positioned, namely an output loop, and is generally applied to an automatic control circuit, and an automatic switch which uses smaller current to control larger current plays roles of automatic control, a switching circuit and the like in the circuit.

As shown in fig. 2, the normally closed relay: normally closed means that the 3 and 4 ends of the contact in figure 2 are the two contacts of the relay, and in a natural and unpowered state. If both contacts are conductive, it is referred to as normally closed (NC Normally closed). The contacts in the closed state under the normal (non-energized) condition are called normally closed contacts, and the normally closed contacts are disconnected when the coil is energized.

In this embodiment, the CPU is a core control unit of the motor controller, and all information processing and program running of the controller are controlled by the CPU. The method mainly comprises the steps of controlling time, processing data, executing operation and the like, such as collecting sensor information of gears, throttle, brakes and the like of the pure electric vehicle, and simultaneously, driving and controlling external loads such as relays and the like.

In the embodiment, the driving motor is a permanent magnet synchronous motor and is an important power supply unit of the pure electric vehicle and is used for driving the vehicle to run according to a control instruction.

The working principle of the above embodiment of the present invention is as follows:

the low-voltage power supply KL30 is a storage battery low-voltage power supply of the pure electric vehicle, and provides power input for the system base chip SBC and the power driving power supply KL30-1 respectively.

SBC converts 3.3V and 5V power supply output through an internal voltage conversion circuit, wherein 3.3V pulls up a control pin of Q2 through a resistor R3, when the system works normally, the control pin of Q2 is pulled up to 3.3V, Q2 is in a conducting state, a 1 pin of Q1 is in a low level, Q1 is conducted, and KL30 supplies power to a high-side driving module U1 through a first transistor switch Q1;

when a fault is diagnosed, the control output of the SBC may turn Q2 off by outputting a low level, thereby turning Q1 off.

The high-side driving module U1 is provided with two paths of power supplies for supplying power, wherein the first path is 5V power supply and is provided by a third output end S3 of the SBC, so that the power supply is used for supplying power to the inside of a chip of the high-side driving module U1 and is used for ensuring the normal operation of the chip, the second path is U1 power supply and is provided by KL30-1, the power supply is used for supplying power to a first relay J1 and a second relay J2, driving output is provided for the first relay J1 and the second relay J2 through a U1 internal switching circuit, two signals of the relay control 1 and the relay control 2 are respectively controlled by two signals of the CPU control output 1 and the CPU control output 2, and when the two signals of the CPU control output 1 and the CPU control output 2 are at a high level, the two signals of the relay control 1 and the relay control 2 are used for driving output enabling, and the first relay J1 and the second relay J2 are in an upper electrical state;

when the two signals of the CPU control output 1 and the CPU control output 2 are at a low level, the two signals of the relay control 1 and the relay control 2 drive the output to be enabled to be closed, and the relay is powered down and is in a non-working state.

The first relay J1 and the second relay J2 are respectively controlled by two signals of the relay control 1 and the relay control 2, when the two signals of the relay control 1 and the relay control 2 output driving enabling signals, the first relay J1 and the second relay J2 start to work, and as the used relay is a normally closed type relay, contacts of the relay are in an open state in a working state, at the moment, a U, V, W three-phase driving loop of the permanent magnet synchronous motor is in an open state, and a vehicle normally runs;

when the two signals of the relay control 1 and the relay control 2 do not output driving enabling signals, the first relay J1 and the second relay J2 stop working, and as the used relay is a normally closed relay, the contacts of the relay are in a closed state in a non-working state of the relay, and at the moment, a short circuit state is arranged between U, V, W three-phase driving loops of the permanent magnet synchronous motor, a safety protection mechanism of a motor controller is triggered, and a vehicle enters a limp state to remind a driver to drive away from the vehicle as soon as possible.

According to the embodiment of the invention, KL30 provides power input for SBC and KL30-1 respectively, 3.3V and 5V power output by the SBC supply power to the high-side driving module U1 and the CPU, normal operation of the system is ensured, the high-side driving module U1 outputs two driving signals of the relay control 1 and the relay control 2, the first relay J1 and the second relay J2 are electrically operated on two normally closed relays, the contacts of the normally closed relays are in an off state, the U, V, W three-phase driving loop of the permanent magnet synchronous motor is in an off state, and the vehicle normally runs.

When a fault occurs, three fault states are described:

1) When the low-voltage power supply fails, the SBC controls and outputs a low level to control the MOSFET second transistor switch Q2 (MOSFET) to act, Q2 is switched from an on state to an off state, meanwhile, the 1 pin of Q1 is switched from the low level to the high level, and Q1 is switched off;

after Q1 is turned off, KL30-1 loses power, and as KL30-1 supplies power for the power of the high-side driving module U1, after Q1 is turned off, relay control 1 and relay control 2 disappear, and the first relay J1 and the second relay J2 are changed from the working state to the non-working state;

because the two contacts of the first relay J1 and the second relay J2 in the non-working state are in the closed state, the U-phase and V-phase, V-phase and W-phase driving loops of the driving motor respectively enter a short circuit state, and the vehicle enters a limp state to remind a driver to stop the vehicle as soon as possible.

2) When the low-voltage power supply is completely failed, even if all the most extreme low-voltage power supply is completely interrupted, the KL30-1 loses power, so that the power supply of the high-side driving module U1 loses power, and the first relay J1 and the second relay J2 are in a non-working state;

because the two contacts of the first relay J1 and the second relay J2 in the non-working state are in the closed state, the U-phase driving circuit, the V-phase driving circuit and the W-phase driving circuit of the motor respectively enter a short circuit state, and the vehicle enters a limp state.

Here, the normally closed relay is adopted to realize that the U-phase and V-phase, V-phase and W-phase driving circuits of the motor can still respectively enter a short circuit state even when a low-voltage power supply failure, even a complete failure of the power supply and a torque control logic failure occur.

3) When the low-voltage power supply is normal and the torque control logic of the controller is failed, the CPU control output 1 and the CPU control output 2 are changed from high level to low level, the driving output of the relay control 1 and the relay control 2 is closed, and the relay is changed from the working state to the non-working state;

similarly, the U-phase and V-phase, V-phase and W-phase drive circuits of the motor respectively enter a short circuit state, and the vehicle enters a limp state.

In addition, the IGBT (insulated gate bipolar transistor) circuit of the motor controller can be controlled to enable the upper bridge arm or the lower bridge arm of the U, V, W three-phase motor controller to enter a short circuit state so as to realize the safety protection function, but the scheme can be realized only under the condition that the controller low-voltage power supply works normally, and if the power supply of the low-voltage power supply fails, the safety protection function cannot be realized.

The embodiment of the invention also provides an electric automobile, which comprises the control circuit of the driving motor. All the implementation modes in the control circuit are applicable to the embodiment of the electric automobile, and the same technical effects can be achieved. According to the embodiment of the invention, the potential risks in the two aspects of hardware and software of the motor controller are diagnosed respectively, so that the passive safety performance of the automobile is greatly improved. The protection function can be realized even under the condition of low-voltage power failure of the controller, the driver is reminded to stop the vehicle as soon as possible, and the personal safety is ensured.

While the foregoing is directed to the preferred embodiments of the present invention, it will be appreciated by those skilled in the art that various modifications and adaptations can be made without departing from the principles of the present invention, and such modifications and adaptations are intended to be comprehended within the scope of the present invention.

Claims (10)

1. A control circuit of a driving motor of an electric vehicle, comprising:

a first detection circuit (11) electrically connected with a low-voltage power supply (KL 30) of the electric automobile, and used for outputting a first control signal when detecting the fault of the low-voltage power supply (KL 30);

a second detection circuit (12) electrically connected to the first detection circuit (11), wherein the second detection circuit (12) is powered by the first detection circuit (11) and is configured to output a second control signal when the low-voltage power supply (KL 30) is normally powered and a torque control logic of a motor controller of the electric automobile fails;

and the control circuit (13) is electrically connected with the first detection circuit (11) and the second detection circuit (12) respectively and is used for controlling the driving motor of the electric automobile to be in short circuit according to the first control signal or the second control signal.

2. The control circuit of a drive motor of an electric vehicle according to claim 1, wherein the first detection circuit (11) includes:

a system base chip SBC, wherein the input end of the system base chip SBC is electrically connected with the low-voltage power supply (KL 30);

a first transistor switch (Q1) electrically connected to the low-voltage power supply (KL 30), the first transistor switch (Q1) being electrically connected to the output of the system base chip SBC through a second transistor switch (Q2);

when the system base chip SBC detects that the low-voltage power supply KL30 fails, a first low-level signal is output to the second transistor switch (Q2), 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).

3. The control circuit of a driving motor of an electric vehicle according to claim 2, wherein the output terminal of the system base chip SBC includes: a first output (S1), a second output (S2) and a third output (S3);

the first output end (S1) is electrically connected with the second transistor switch (Q2) through a first resistor (R1);

the second output end (S2) is electrically connected with the second transistor switch (Q2) through a third resistor (R3);

the second transistor switch (Q2) is electrically connected to the low voltage power supply (KL 30) through a second resistor (R2);

a source of the second transistor switch (Q2) is electrically connected to a gate of the first transistor switch (Q1);

the third output end (S3) is electrically connected with the second detection circuit (12) and supplies power for the second detection circuit (12);

the system base chip SBC outputs a first low-level signal to the second transistor switch (Q2) when detecting a failure of the low-voltage power supply (KL 30).

4. The control circuit for a driving motor of an electric vehicle according to claim 3, wherein,

when the system base chip SBC detects that the low-voltage power supply (KL 30) supplies power normally, the second output end (S2) outputs target voltage to the second transistor switch (Q2) through the third resistor (R3), the second transistor switch (Q2) is conducted, the first transistor switch (Q1) is conducted, and a third control signal is output to the control circuit (13) through the second detection circuit (12);

the control circuit (13) controls the driving motor to work normally according to the third control signal.

5. A control circuit of a drive motor of an electric vehicle according to claim 3, characterized in that the second detection circuit (12) comprises:

a Central Processing Unit (CPU), wherein the input end of the CPU is electrically connected with the third output end (S3) of the system base chip SBC;

a high-side driving module (U1) electrically connected to the output end of the central processing unit CPU and the third output end (S3) of the system base chip SBC, respectively, the high-side driving module (U1) being electrically connected to a power driving power supply (KL 30-1), the power driving power supply (KL 30-1) being electrically connected to the drain electrode of the first transistor switch (Q1);

the system base chip SBC provides a low-voltage power supply for the high-side driving module (U1) through the third output end (S3);

the power driving power supply (KL 30-1) provides power supply to the high-side driving module (U1);

when the CPU detects that the low-voltage power supply source (KL 30) supplies power normally and the torque control logic of the motor controller of the electric automobile fails, a second low-level signal is output to the high-side driving module (U1) through the output end of the CPU, so that the high-side driving module (U1) sends a second control signal to the control circuit.

6. The control circuit of a driving motor of an electric vehicle according to claim 5, wherein when the central processing unit CPU detects that a low-voltage power supply (KL 30) supplies power normally and torque control logic of a motor controller of the electric vehicle is not failed, a high-level signal is output to the high-side driving module (U1) through an output end of the central processing unit CPU, so that the high-side driving module (U1) sends a fourth control signal to the control circuit;

the control circuit (13) controls the driving motor to work normally according to the fourth control signal.

7. The control circuit of the driving motor of the electric vehicle according to claim 6, wherein an output terminal of the central processing unit CPU includes: a first output (C1) and a second output (C2);

the CPU outputs the second low level signal or the high level signal to the high side driving module (U1) through the first output end (C1) and the second output end (C2).

8. The control circuit of a drive motor of an electric vehicle according to claim 7, characterized in that the control circuit comprises:

a first relay (J1) and a second relay (J2) electrically connected to the high-side drive module (U1);

the first relay (J1) is electrically connected with a U phase, a V phase and a V phase of the driving motor;

the second relay (J2) is electrically connected with a W phase and a V phase of the driving motor;

when the first relay (J1) and the second relay (J2) receive a second control signal sent by the high-side driving module (U1) according to the second low-level signal, the first relay (J1) and the second relay (J2) are controlled to be in a power-down state, and a U, V, W three-phase driving loop of the driving motor is in a short circuit state.

9. The control circuit of a driving motor of an electric vehicle according to claim 8, wherein the first relay (J1) and the second relay (J2) are both normally closed relays; the first relay (J1) and the second relay (J2) are in a closed state when in a power-down state.

10. An electric vehicle, characterized by comprising a control circuit of the drive motor according to any one of claims 1 to 9.

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