Braking control method for electric vehicle and electric vehicle

Abstract

The application provides a brake control method of an electric vehicle and the electric vehicle, and belongs to the technical field of brake control of electric vehicles. The current speed of the electric vehicle and the opening degree of the current pedal are obtained, a corresponding relationship between the pedal opening degree, the speed and the target deceleration is obtained in advance, the target deceleration corresponding to the current speed and the current pedal opening degree is extracted, the target deceleration is taken as a control target of brake control, and the vehicle sliding resistance is calculated according to the current speed; the slope of the road section where the electric vehicle is currently located is obtained, and the slope resistance is calculated according to the slope; then, the requested brake torque is calculated according to the vehicle sliding resistance, the slope resistance and the target deceleration value, and the driving motor is controlled to output the requested brake torque. By taking the target deceleration as the brake control target and adaptively calculating the requested brake torque output by the driving motor according to the slope of the road section, the driving motor outputs the requested brake torque, and the driving experience is optimized.

Description

Technical Field

[0001] This invention relates to a braking control method for an electric vehicle and an electric vehicle, belonging to the field of electric vehicle braking control technology. Background Technology

[0002] With the continuous development of new energy technologies, electric vehicles or hybrid vehicles are gradually gaining market recognition and consumer favor due to their numerous advantages such as fast acceleration, zero emissions, low noise, and low energy consumption. Pure electric buses, with their simple system architecture, high efficiency, and clean energy usage, have become the development trend of bus systems.

[0003] When traditional gasoline-powered cars decelerate, the wheel brakes apply braking force to the wheels, converting the kinetic energy of the vehicle's motion into heat energy and releasing it into the air, thus slowing down the vehicle. However, for electric or hybrid vehicles, this kinetic energy wasted due to braking can be converted into electrical energy and stored in the electric vehicle's power battery through coasting energy recovery technology, thereby improving energy utilization.

[0004] Currently, the coasting recovery torque of the single-pedal function developed by passenger car OEMs is a fixed value, which cannot adapt to the slope and cause inconsistent deceleration when coasting on different slopes. This affects the drag feeling when releasing the pedal, especially in single-pedal mode, making it difficult to provide the driver with the correct feeling of vehicle deceleration, thus affecting the safe driving of the vehicle and reducing the user's driving experience. Summary of the Invention

[0005] The purpose of this invention is to provide a braking control method for electric vehicles and an electric vehicle in order to solve the problem that existing electric vehicles are unable to provide a good driving experience for drivers.

[0006] To achieve the above objectives, the present invention provides a braking control method for an electric vehicle, comprising the following steps:

[0007] 1) Obtain the current vehicle speed and the current pedal opening of the electric vehicle. Based on the pre-obtained correspondence between pedal opening, vehicle speed and target deceleration, obtain the target deceleration value corresponding to the current vehicle speed and current pedal opening, and calculate the coasting resistance based on the current vehicle speed.

[0008] 2) Obtain the gradient of the road segment where the electric vehicle is currently located, and calculate the slope resistance based on the gradient;

[0009] 3) Calculate the requested braking torque based on the sliding resistance, gradient resistance, and target deceleration value;

[0010] 4) Control the drive motor to output the requested braking torque.

[0011] The electric vehicle braking control method of the present invention acquires the current vehicle speed and current pedal opening of the electric vehicle. Based on the pre-acquired correspondence between pedal opening, vehicle speed, and target deceleration, it extracts the target deceleration corresponding to the current vehicle speed and current pedal opening, and uses the target deceleration as the control target for braking control. It also calculates the vehicle's coasting resistance based on the current vehicle speed. Furthermore, it acquires the slope of the road segment where the electric vehicle is currently located and calculates the slope resistance. Then, based on the vehicle's coasting resistance, slope resistance, and target deceleration value, it calculates the requested braking torque and controls the drive motor to output the requested braking torque. By using the present invention, by using the target deceleration as the braking control target and adaptively calculating the requested braking torque output by the drive motor based on the slope of the road segment, the drive motor adopts the requested braking torque output, thus optimizing the driving experience.

[0012] Furthermore, in the above method, the pedal has a single-pedal function. In step S1, if the current pedal opening is less than the set opening, the target deceleration value corresponding to the current vehicle speed and the current pedal opening is obtained according to the pre-obtained correspondence between the pedal opening, vehicle speed and target deceleration.

[0013] The pedal with single-pedal function outputs an acceleration command when the pedal opening is greater than the set opening, and outputs a kinetic energy recovery command when the pedal opening is less than the set opening.

[0014] Electric vehicles use a single-pedal brake control system. When the current pedal opening is greater than the set opening, an acceleration command is output; when the pedal opening is less than the set opening, a kinetic energy recovery command is output. Based on the pre-obtained correspondence between pedal opening, vehicle speed, and target deceleration, a target deceleration value corresponding to the current vehicle speed and current pedal opening is obtained. Using the target deceleration as the braking control target not only meets the driver's braking needs but also provides a good driving experience and reduces energy consumption during braking.

[0015] Furthermore, in the above method, in step 4), when controlling the drive motor to output the requested braking torque, the vehicle recovery torque limit is also obtained; if the requested braking torque is greater than the vehicle recovery torque limit, the difference between the requested braking torque and the vehicle recovery torque limit is calculated, and the drive motor is controlled to perform braking compensation based on the difference.

[0016] When controlling the output of the drive motor to request braking torque, considering that the braking torque applied by a single pedal cannot reach the original torque, the vehicle recovery torque limit is also obtained, and braking compensation is performed based on the difference between the requested braking torque and the vehicle recovery torque limit.

[0017] Furthermore, in the above method, the vehicle's regenerative torque limit is obtained through the following steps:

[0018] 1) Obtain the charging power limit P of the power battery BattChrg The current speed n of the drive motor and the operating efficiency of the drive motor Based on the transmission ratio i0, the charging power torque limit of the power battery is calculated using the following formula. :

[0019]

[0020] 2) Obtain the maximum torque limit of the drive motor recovery Limit the charging power and torque of the power battery Maximum torque limit of drive motor recovery The smaller value between these two values ​​is used as the limit for the vehicle's regenerative torque.

[0021] By obtaining the charging power limit P of the power battery BattChrg The current speed n of the drive motor and the operating efficiency of the drive motor The calculation is simple and easy to implement. The power battery charging power torque limit is calculated, and then the smaller value between the power battery charging power torque limit and the drive motor recovery maximum torque limit is used as the vehicle recovery torque limit.

[0022] Furthermore, in the above method, in step 3), the requested braking torque is calculated using the following formula:

[0023]

[0024] In the formula, To request braking torque, For the sake of the whole vehicle, For slope resistance, The resistance to vehicle sliding is r, and the wheel radius is r. This refers to the transmission ratio between the drive motor and the wheels.

[0025] A specific formula for calculating the required braking torque is proposed to facilitate implementation.

[0026] Furthermore, the above method also includes a step of judging the energy recovery capability during the braking control of the electric vehicle. If the charging power limit of the power battery is less than the set power, or the temperature of the power battery is greater than the first set temperature, or the SOC of the power battery is greater than the set threshold, or the temperature of the drive motor is greater than the second set temperature, or the temperature of the drive motor controller is greater than the third set temperature, or there is a communication failure between the vehicle controller and the battery management system or the drive motor controller, then the energy recovery capability is considered weak.

[0027] During the braking control process of an electric vehicle, the energy recovery capability is judged by the power battery charging power limit, power battery temperature, power battery SOC, drive motor temperature, drive motor controller MCU temperature, and whether the vehicle controller VCU has a communication failure with the battery management system BMS or drive motor controller MCU, so as to prompt the driver when the energy recovery capability is weak.

[0028] Furthermore, in the above method, when the energy recovery capability is weak, a symbol is displayed to warn the driver.

[0029] The symbol chip alerts the driver when the energy recovery capability is weak, making it easy for the driver to observe and understand the operation of the regenerative braking function in real time, thus avoiding misuse when the recovery function is limited.

[0030] The present invention also provides an electric vehicle, including a vehicle controller, wherein the vehicle controller executes instructions to implement the above-described braking control method for the electric vehicle. Attached Figure Description

[0031] Figure 1 This is a flowchart of the braking control method for an electric vehicle in an embodiment of the present invention;

[0032] Figure 2 This is an equivalent schematic diagram showing the location of the electric vehicle in an embodiment of the method of the present invention;

[0033] Figure 3 This is a schematic diagram of the electric vehicle mechanical analysis in an embodiment of the method of the present invention;

[0034] Figure 4 This is a structural block diagram of the electric vehicle in an embodiment of the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0036] Method Implementation Examples:

[0037] This invention provides a braking control method for electric vehicles. By optimizing the pedal torque calculation logic, the slope of the current road segment of the electric vehicle is introduced as a parameter for calculating the pedal torque. The target deceleration that the electric vehicle needs to achieve on the current road segment is used as the braking control target. When the single pedal opening is less than a set value, the requested braking torque, i.e., the original torque, is calculated and the drive motor is controlled to output the original torque. The original torque is also compared with the vehicle's regenerative torque limit. When the original torque is greater than the vehicle's regenerative torque limit, braking compensation is performed based on the portion of the original torque that exceeds the vehicle's regenerative torque limit. This ensures that the driver has a correct sense of vehicle deceleration when the electric vehicle is driving on road segments with different slopes, thereby improving the safety and stability of vehicle operation.

[0038] Electric vehicles use a single-pedal pedal for acceleration control and energy recovery control. When the single-pedal pedal is pressed, the pedal opening gradually increases until the set opening is reached, at which point an acceleration command is output. When the single-pedal pedal is released, the pedal opening gradually decreases until it falls below the set opening, at which point an energy recovery command is output.

[0039] The process of electric vehicle braking control method is as follows: Figure 1 As shown, it includes the following steps:

[0040] 1) Detect the single pedal opening. If the single pedal opening is less than 50%, proceed to step 2) to calculate the original torque of the requested motor. This refers to requesting the braking torque output from the drive motor; if the single pedal opening is greater than or equal to 50%, then requesting the original torque of the motor. It is 0.

[0041] 2) The vehicle controller (VCU) extracts the target deceleration value 'a' corresponding to the single pedal opening and the current vehicle speed from the pre-set correspondence between pedal opening, vehicle speed and target deceleration based on the current vehicle speed and the single pedal opening. The target deceleration value 'a' is used as the braking control target of the electric vehicle in the current road segment.

[0042] Based on the current vehicle speed, the sliding resistance is calculated using formula (1). :

[0043] (1)

[0044] In the formula, A, B, and C are all sliding resistance coefficients, and v is the current speed of the electric vehicle.

[0045] The coasting drag coefficient is calibrated based on a whole vehicle coasting test. The test procedure is as follows: In an open area, the electric vehicle is driven to its maximum speed and then enters a coasting state in neutral. During the coasting process, the vehicle's coasting trajectory is collected, i.e., the relationship between coasting speed and coasting time. A mechanical analysis of the electric vehicle during the coasting process is performed, and the force F acting on the electric vehicle at different speeds v is calculated using the formula... Find the sliding resistance coefficients A, B, and C.

[0046] Based on the electric vehicle's mass m and the target deceleration value a, the resultant force of the entire vehicle is calculated using formula (2). That is, the net force of a single pedal:

[0047] (2)

[0048] The current speed v of an electric vehicle is determined based on the current rotational speed n of the drive motor, the wheel radius r, and the transmission ratio between the wheel and the drive motor. The calculations yielded the wheel radius r and the transmission ratio between the wheel and the drive motor. All are constants for the entire vehicle. The current vehicle speed v is calculated using the following formula (3):

[0049] (3)

[0050] 3) Obtain the slope of the road segment currently in which the electric vehicle is located. The slope is calculated based on the output of the gyroscope in the vehicle controller. For example, if the electric vehicle is traveling on a road segment with a slope of θ... Figure 2 and Figure 3 As shown, the vehicle's acceleration is calculated based on its speed, where the vehicle's speed at time t1 is v1 and its speed at time t2 is v2. The vehicle's acceleration is... If the gyroscope in the vehicle controller outputs the absolute acceleration a2 of the electric vehicle along the forward direction, then the acceleration a1 of the vehicle on the current road segment satisfies: Therefore, the slope can be calculated. .

[0051] 4) Based on the combined force of the whole vehicle Ramp resistance and gliding resistance The original torque of the requested motor is calculated using the following formula (4). :

[0052] (4)

[0053] 5) Control the output torque of the drive motor. Furthermore, considering the possibility that the braking torque applied by a single pedal cannot reach the original torque, air brake compensation is also performed. The vehicle's regenerative torque limit Tmax is obtained and compared with the original torque Topd of the requesting motor. If Topd is greater than Tmax, a 1 is sent to the Electronic Brake Controller (EBS) as a braking force compensation request flag, and the difference between Topd and Tmax is sent to the EBS as the braking force compensation request torque. If Topd is less than Tmax, a 0 is sent to the EBS as a braking force compensation request flag, and a braking force compensation request torque with a value of 0 is sent to the EBS.

[0054] The vehicle's total regenerative torque limit Tmax is based on the charging power limit of the power battery. and drive motor recovery torque limit The smaller of the two values ​​represents the charging power limit of the power battery. The following formula (5) is used to calculate:

[0055] (5)

[0056] In equation (5), Limits on the charging power of power batteries. To improve the operating efficiency of the drive motor.

[0057] 6) When controlling the braking of an electric vehicle according to the above steps, a logical judgment is also made on the energy recovery capability of the electric vehicle during braking based on the power battery charging power limit, power battery temperature, power battery SOC, drive motor temperature, drive motor controller MCU temperature, and whether there is a communication failure between the vehicle controller VCU and the battery management system BMS or drive motor controller MCU. Furthermore, after the one-pedal function is activated, a function-limited flag is output to the instrument panel IP, which displays the corresponding function-limited symbol, indicating a reduction in recovery capability. This symbol, displayed on the instrument panel IP, allows the driver to easily understand the real-time operation of the regenerative braking function and avoids misuse when the function is limited.

[0058] The following seven conditions must be met to determine if recycling capacity has weakened:

[0059] 1) The charging power limit for the power battery is less than 30kW;

[0060] 2) The temperature of the power battery exceeds 45℃;

[0061] 3) The SOC of the power battery is greater than 97%;

[0062] 4) The temperature of the drive motor exceeds 130℃;

[0063] 5) The temperature of the drive motor controller exceeds 84℃;

[0064] 6) There is a communication failure between the vehicle control unit (VCU) and the battery management system (BMS);

[0065] 7) There is a communication failure between the vehicle controller (VCU) and the drive motor controller (MCU).

[0066] When considering that the pedal of an electric vehicle is a regular pedal without a single-pedal function, step 1) is skipped and step 2) is performed directly to start braking control. Those skilled in the art should know how to perform braking control when the pedal of an electric vehicle does not have a single-pedal function, so it will not be described in detail here.

[0067] The braking control method for electric vehicles of the present invention can adaptively calculate the original torque requested by the motor based on the slope of the road segment where the electric vehicle is currently located, thereby avoiding inconsistent deceleration when the slope changes, and improving the safety and stability of vehicle operation. Furthermore, simulation tests using the method of the present invention show that the overall vehicle energy consumption is reduced by approximately 10%, improving kinetic energy recovery efficiency and optimizing overall vehicle economy.

[0068] Electric vehicle example:

[0069] This invention provides an electric vehicle, such as Figure 4 As shown, the electric vehicle includes a Battery Management System (BMS), a Vehicle Control Unit (VCU), a Drive Motor Controller (MCU), an Electronic Brake Controller (EBS), and an Instrument Panel (IP). The VCU includes a vehicle speed calculation module for calculating the current vehicle speed and a gradient calculation module for calculating the current road segment. It also includes a single-pedal base torque calculation module, an air brake compensation module, and a functional limitation judgment module. The single-pedal base torque calculation module calculates the original torque of the requesting motor. The air brake compensation module obtains the vehicle's regenerative torque limit and the original torque and makes a judgment to perform air brake compensation. The functional limitation judgment module judges the energy recovery capability of the electric vehicle during braking.

[0070] The vehicle controller (VCU) connects to the battery management system (BMS) to obtain the power battery charging power limit, power battery temperature, and power battery SOC. It also connects to the drive motor controller (MCU) to obtain the drive motor temperature, drive motor controller temperature, drive motor speed, and drive motor regenerative torque limit sent by the drive motor controller, and sends the single-pedal regenerative torque to it.

[0071] The vehicle control unit (VCU) is also connected to the electronic brake control unit (EBS) to send a brake compensation request flag and a brake compensation torque value to achieve air brake compensation. Hydraulic brake compensation can also be used as another compensation method.

[0072] The vehicle control unit (VCU) is connected to the instrument cluster IP to display a corresponding function limitation symbol when the energy recovery capability is weakened, providing an alarm to the driver and preventing accidental operation.

[0073] The electric vehicle of the present invention implements the braking control method of the electric vehicle in the method embodiment by executing corresponding instructions in the vehicle controller (VCU) to control the braking of the electric vehicle. The implementation of this method has been clearly described in the method embodiment and will not be repeated here.

Claims

1. A braking control method for an electric vehicle, characterized in that, Includes the following steps: 1) Obtain the current speed of the electric vehicle and the current pedal opening of the pedal with single-pedal function. If the current pedal opening is less than the set opening, obtain the target deceleration value corresponding to the current speed and the current pedal opening based on the pre-obtained correspondence between pedal opening, vehicle speed and target deceleration. When the pedal opening is greater than the set opening, it outputs an acceleration command; when the pedal opening is less than the set opening, it outputs a kinetic energy recovery command. 2) Calculate the resultant force of the entire vehicle based on the target deceleration value and the mass of the electric vehicle; calculate the coasting resistance based on the current vehicle speed; obtain the slope of the current road segment where the electric vehicle is located, and calculate the slope resistance based on the slope; The gliding resistance is calculated using the following formula. : In the formula, A, B, and C are all sliding resistance coefficients, and v is the current speed of the electric vehicle; The coasting drag coefficient is calibrated based on a whole vehicle coasting test. The test procedure is as follows: In an open area, the electric vehicle is driven to its maximum speed and then enters neutral coasting mode. During the coasting process, the relationship between coasting speed and coasting time is collected, and a mechanical analysis of the electric vehicle during the coasting process is performed. The coefficient is determined based on different vehicle speeds v. b The force F acting on the electric vehicle is obtained through the formula. Find the sliding resistance coefficients A, B, and C; The slope is calculated based on the gyroscope output, and the vehicle's acceleration is calculated based on the vehicle speed, where the vehicle speed at time t1 is v1 and the vehicle speed at time t2 is v2. The vehicle acceleration is then... If the gyroscope outputs the absolute acceleration a2 of the electric vehicle along the forward direction, then the acceleration a1 of the entire vehicle on the current road segment satisfies: Calculate the slope ; 3) Calculate the required braking torque based on the coasting resistance, gradient resistance, and the resultant force of the entire vehicle; 4) When controlling the drive motor to output the requested braking torque, the vehicle recovery torque limit is also obtained; if the requested braking torque is greater than the vehicle recovery torque limit, the difference between the requested braking torque and the vehicle recovery torque limit is calculated, and the difference is used as the braking force compensation request torque for air braking compensation.

2. The braking control method for an electric vehicle according to claim 1, characterized in that, The current speed of an electric vehicle is calculated based on the current rotational speed n of the drive motor, the wheel radius r, and the transmission ratio i0 between the wheel and the drive motor.

3. The braking control method for an electric vehicle according to claim 2, characterized in that, The current vehicle speed v is calculated using the following formula: Where n is the current speed of the drive motor, and r is the wheel radius. This is the transmission ratio between the wheel and the drive motor.

4. The braking control method for an electric vehicle according to claim 1, characterized in that, The vehicle recovery torque limit is obtained by following these steps: 1) Obtain the charging power limit P of the power battery BattChrg The current speed n of the drive motor and the operating efficiency of the drive motor Based on the transmission ratio i0, the charging power torque limit of the power battery is calculated using the following formula. : 2) Obtain the maximum torque limit of the drive motor recovery Limit the charging power and torque of the power battery Maximum torque limit of drive motor recovery The smaller value between these two values ​​is used as the limit for the vehicle's regenerative torque.

5. The braking control method for an electric vehicle according to claim 1, characterized in that, In step 3), the requested braking torque is calculated using the following formula: In the formula, To request braking torque, For the sake of the whole vehicle, For slope resistance, The resistance to vehicle sliding is r, and the wheel radius is r. This refers to the transmission ratio between the drive motor and the wheels.

6. The braking control method for an electric vehicle according to claim 1, characterized in that, It also includes a step for judging the energy recovery capability during the braking control of electric vehicles. If the power battery charging power limit is less than the set power, or the power battery temperature is greater than the first set temperature, or the power battery SOC is greater than the set threshold, or the drive motor temperature is greater than the second set temperature, or the drive motor controller temperature is greater than the third set temperature, or there is a communication failure between the vehicle controller and the battery management system or the drive motor controller, then the energy recovery capability is considered weak.

7. The braking control method for an electric vehicle according to claim 6, characterized in that, When energy recovery capability is weak, a warning sign will be displayed to alert the driver.

8. An electric vehicle, characterized in that, The system includes a vehicle controller, which executes instructions to implement a braking control method for an electric vehicle; the braking control method for the electric vehicle includes the following steps: 1) Obtain the current speed of the electric vehicle and the current pedal opening of the pedal with single-pedal function. If the current pedal opening is less than the set opening, obtain the target deceleration value corresponding to the current speed and the current pedal opening based on the pre-obtained correspondence between pedal opening, vehicle speed and target deceleration. When the pedal opening is greater than the set opening, it outputs an acceleration command; when the pedal opening is less than the set opening, it outputs a kinetic energy recovery command. 2) Calculate the resultant force of the entire vehicle based on the target deceleration value and the mass of the electric vehicle; calculate the coasting resistance based on the current vehicle speed; obtain the slope of the current road segment where the electric vehicle is located, and calculate the slope resistance based on the slope; The gliding resistance is calculated using the following formula. : In the formula, A, B, and C are all sliding resistance coefficients, and v is the current speed of the electric vehicle; The coasting drag coefficient is calibrated based on a whole vehicle coasting test. The test procedure is as follows: In an open area, the electric vehicle is driven to its maximum speed and then enters neutral coasting mode. During the coasting process, the relationship between coasting speed and coasting time is collected, and a mechanical analysis of the electric vehicle during the coasting process is performed. The coefficient is determined based on different vehicle speeds v. b The force F acting on the electric vehicle is obtained through the formula. Find the sliding resistance coefficients A, B, and C; The slope is calculated based on the gyroscope output, and the vehicle's acceleration is calculated based on the vehicle speed, where the vehicle speed at time t1 is v1 and the vehicle speed at time t2 is v2. The vehicle acceleration is then... If the gyroscope outputs the absolute acceleration a2 of the electric vehicle along the forward direction, then the acceleration a1 of the entire vehicle on the current road segment satisfies: Calculate the slope ; 3) Calculate the required braking torque based on the coasting resistance, gradient resistance, and the resultant force of the entire vehicle; 4) When controlling the drive motor to output the requested braking torque, the vehicle recovery torque limit is also obtained; if the requested braking torque is greater than the vehicle recovery torque limit, the difference between the requested braking torque and the vehicle recovery torque limit is calculated, and the difference is used as the braking force compensation request torque for air braking compensation.

9. The electric vehicle according to claim 8, characterized in that, The current speed of an electric vehicle is calculated based on the current rotational speed n of the drive motor, the wheel radius r, and the transmission ratio i0 between the wheel and the drive motor.

10. The electric vehicle according to claim 9, characterized in that, The current vehicle speed v is calculated using the following formula: Where n is the current speed of the drive motor, and r is the wheel radius. This is the transmission ratio between the wheel and the drive motor.

11. The electric vehicle according to claim 8, characterized in that, The vehicle recovery torque limit is obtained by following these steps: 1) Obtain the charging power limit P of the power battery BattChrg The current speed n of the drive motor and the operating efficiency of the drive motor Based on the transmission ratio i0, the charging power torque limit of the power battery is calculated using the following formula. : 2) Obtain the maximum torque limit of the drive motor recovery Limit the charging power and torque of the power battery Maximum torque limit of drive motor recovery The smaller value between these two values ​​is used as the limit for the vehicle's regenerative torque.

12. The electric vehicle according to claim 8, characterized in that, In step 3), the requested braking torque is calculated using the following formula: In the formula, To request braking torque, For the sake of the whole vehicle, For slope resistance, The resistance to vehicle sliding is r, and the wheel radius is r. This refers to the transmission ratio between the drive motor and the wheels.

13. The electric vehicle according to claim 8, characterized in that, It also includes a step for judging the energy recovery capability during the braking control of electric vehicles. If the power battery charging power limit is less than the set power, or the power battery temperature is greater than the first set temperature, or the power battery SOC is greater than the set threshold, or the drive motor temperature is greater than the second set temperature, or the drive motor controller temperature is greater than the third set temperature, or there is a communication failure between the vehicle controller and the battery management system or the drive motor controller, then the energy recovery capability is considered weak.

14. The electric vehicle according to claim 13, characterized in that, When energy recovery capability is weak, a warning sign will be displayed to alert the driver.

Images