An electric vehicle and an energy recovery compensation method, system and storage medium thereof

Abstract

The application discloses an electric vehicle and an energy recovery compensation method and system thereof and a storage medium, and belongs to the technical field of electric vehicles, and the method comprises the following steps: receiving a current motor torque and a current motor speed; determining whether the product value of the current motor speed and the current motor torque is positive, if yes, controlling the motor to enter a discharging mode, and if no, controlling the motor to enter a power generation mode; determining whether a current battery SOC value is greater than or equal to 95%, if no, calculating an energy recovery torque by a vehicle controller according to a recoverable power of the battery, the current motor speed and a brake pedal opening, and sending the energy recovery torque data to a motor controller, and if yes, calculating a current energy recovery power P according to a real-time working power P DC of a low-voltage power supply system, a real-time working power P EC of an air conditioner compressor and a current motor speed. The application prevents battery overcharging and reduces the risk of overheating of a brake drum by braking through energy recovery.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, and in particular to an energy recovery and compensation method for electric vehicles. Background Technology

[0002] With the continuous promotion of new energy vehicles, more and more fields are beginning to recognize their advantages. Compared with fuel vehicles, new energy vehicles have the characteristics of faster acceleration, higher efficiency, and lower operating costs. The regenerative braking system of electric vehicles can recover excess energy released during braking or coasting and store it for reuse. It has been proven that the regenerative braking system can not only improve the vehicle's range by recovering energy, but also improve the driving experience to a certain extent. It is another very important operating system for electric vehicles besides the "three-electric system" (battery, motor, and electronic control system). Currently, the energy recovery system is designed to disable motor energy recovery when the battery's remaining charge (SOC) exceeds 95%. Because the battery charge is high, the vehicle control unit (VCU) will disable energy recovery when the battery is recharged to prevent overcharging.

[0003] The existing energy recovery strategies for electric vehicles are as follows:

[0004] (1) SOC < 95%: The VCU enters the energy recovery mode according to the current driving state (coasting in D gear or braking state), the VCU sends a power generation command, and the motor and motor controller enter the power generation mode; at the same time, the VCU calculates the current energy recovery torque command according to the current speed, brake pedal opening and battery recoverable power, and the motor performs energy recovery according to the power generation command and energy recovery torque command.

[0005] (2) SOC≥95%: The Battery Management System (BMS) sends a message that the recoverable power is 0, and the VCU is prohibited from entering energy recovery.

[0006] Based on the energy recovery technology described above, it is known that when the State of Charge (SOC) exceeds 95%, the vehicle cannot engage in energy recovery, which reduces energy recovery efficiency and driving range. Furthermore, without energy recovery, braking increases brake usage, raising the risk of brake drum overheating, especially during downhill driving in mountainous areas. Summary of the Invention

[0007] In view of the above, the present invention aims to provide an electric vehicle and its energy recovery compensation method and system, which can perform braking through energy recovery when the battery SOC is ≥ 95%, thereby reducing the risk of brake drum overheating.

[0008] The technical solution adopted in this invention is as follows:

[0009] This invention provides an energy recovery compensation method for electric vehicles, comprising the following steps:

[0010] S1: Receives the current motor torque and current motor speed;

[0011] S2: Determine whether the product of the current motor speed and the current motor torque is positive. If it is, control the motor to enter the discharge mode. If not, control the motor to enter the power generation mode and proceed to step S3.

[0012] S3: Receive the current battery SOC value;

[0013] S4: Determine whether the current battery SOC value is ≥95%. If not, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller. If yes, proceed to step S5.

[0014] S5: Calculate the real-time operating power P of the low-voltage power supply system DC Real-time operating power P of air conditioner compressor EC ;

[0015] S6: Calculate the current energy recovery power P, P = P DC +P EC ;

[0016] S7: Based on the current energy recovery power P and the current motor speed, calculate the motor recovery torque and send the motor recovery torque to the motor controller;

[0017] S8: Energy recovery control is performed by the motor controller based on the energy recovery torque sent in step S4 or the motor recovery torque calculated in step S7.

[0018] Optionally, in step S4, the vehicle controller sends the energy recovery torque data to the motor controller via the CAN bus.

[0019] Optionally, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, using the following formula:

[0020] T_rec = T_max * BPO,

[0021] Where T_rec is the energy recovery torque, T_max is the maximum recoverable torque calculated based on the battery's recoverable power and the current motor speed without considering the brake pedal opening, and BPO is the brake pedal opening, which is used to adjust the energy recovery torque.

[0022] Optionally, step S6 specifically includes:

[0023] S61: The low-voltage power supply system uses its own collected current I DC and voltage value UDC Calculate the real-time power P of the low-voltage power supply system DC =I DC *U DC The air conditioner compressor uses the current I it collects. EC and voltage value U EC Calculate the real-time power P of the air conditioner compressor. EC =I EC *U EC ;

[0024] S62: The low-voltage power supply system and the air conditioning compressor respectively send their real-time power to the vehicle controller via the CAN bus. The vehicle controller calculates the current recoverable power: P = P0 DC +P EC .

[0025] Optionally, based on the current recoverable power P calculated in step S6 and combined with the current motor speed, the motor recovery torque is calculated in reverse. The formula for the reverse calculation is:

[0026] P = Motor recovery torque * Current motor speed / 9550.

[0027] Optionally, the motor recovery torque value calculated in step S6 is sent to the motor controller via the CAN bus.

[0028] The present invention also provides an energy recovery compensation system for electric vehicles, comprising:

[0029] The first acquisition module is used to receive the current motor torque and the current motor speed;

[0030] The first determining module is used to calculate whether the product of the current motor speed and the current motor torque is positive. If it is, the motor is controlled to enter the discharge mode; if not, the motor is controlled to enter the power generation mode.

[0031] The second acquisition module is used to receive the current battery SOC value;

[0032] The second determining module is used to determine whether the current battery SOC value is ≥95%. If not, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller. If yes, it calculates the real-time operating power P of the low-voltage power supply system. DC Real-time operating power P of air conditioner compressor EC ;

[0033] The first calculation module is used to calculate the current energy recovery power P, P = P DC +P EC ;

[0034] The second calculation module is used to calculate the motor recovery torque based on the current energy recovery power and the current motor speed, and send the motor recovery torque to the motor controller.

[0035] The execution control module performs energy recovery control based on the energy recovery torque or the motor recovery torque through the motor controller.

[0036] The present invention also provides an electric vehicle, including a controller, the controller being used to execute the above-described energy recovery compensation method for an electric vehicle, or including the above-described energy recovery compensation system for an electric vehicle.

[0037] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, is implemented to perform the above-described energy recovery compensation method for electric vehicles.

[0038] In the electric vehicle and its energy recovery compensation method and system provided by this invention, when the current battery SOC value is determined to be <95%, the vehicle controller calculates the energy recovery torque based on the battery's recoverable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller; if the SOC value is ≥95%, the real-time operating power P of the low-voltage power supply system is calculated. DC Real-time operating power P of air conditioner compressor EC Then calculate the current energy recovery power P, P = P DC +P EC Based on the current energy recovery power P and the current motor speed, the motor recovery torque is calculated and sent to the motor controller. The motor controller then performs energy recovery control based on the energy recovery torque or the motor recovery torque. By implementing the control scheme of this invention, the vehicle can still perform energy recovery when the battery SOC is ≥ 95%, increasing the vehicle's range and reducing energy consumption. Furthermore, when the battery SOC is ≥ 95%, braking can be performed through energy recovery to prevent battery overcharging and reduce the risk of brake drum overheating, especially during downhill driving in mountainous areas. Attached Figure Description

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described below with reference to the accompanying drawings, wherein:

[0040] Figure 1 This is a schematic diagram of an energy recovery and compensation method for electric vehicles provided in an embodiment of the present invention. Detailed Implementation

[0041] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0042] Energy recovery in electric vehicles is a highly efficient technology that allows vehicles to convert kinetic energy into electrical energy during deceleration or braking and store it in the battery, thus improving energy efficiency. This energy recovery system has a positive impact on the driving range and overall performance of electric vehicles. The energy recovery process mainly occurs when the vehicle decelerates or brakes. When the driver releases the accelerator or presses the brake pedal, the electric vehicle's motor switches to generator mode, converting the kinetic energy of the wheels into electrical energy through braking. The electrical energy generated by the motor is then transferred to the battery for later use. The benefits of energy recovery are obvious. First, it can significantly increase the driving range of electric vehicles by recovering the energy generated during braking and coasting and storing it in the battery, thus extending the vehicle's travel distance to some extent. Second, energy recovery reduces reliance on the braking system, thereby extending the lifespan of brake pads.

[0043] However, it's important to note that energy recovery systems cannot completely solve all the problems of electric vehicles. In real-world scenarios, the electrical energy generated during energy recovery may place a certain load on the battery. Current technologies use the vehicle control unit (VCU) to disable motor energy recovery to prevent overcharging of the battery, which further reduces energy recovery efficiency and driving range.

[0044] This invention proposes an embodiment of an energy recovery and compensation method for electric vehicles, specifically, as follows: Figure 1 As shown, it includes the following steps:

[0045] S1: Receives the current motor torque and current motor speed;

[0046] Specifically, the current motor torque and current motor speed are received through the vehicle controller. The wheels of the electric vehicle are connected to the rollers of the dynamometer. The dynamometer calculates the wheel torque by measuring the torque and speed of the rollers. The speed is directly read by the speed sensor equipped on the motor.

[0047] S2: Determine whether the product of the current motor speed and the current motor torque is positive. If yes, control the motor to enter the discharge mode. If no, control the motor to enter the power generation mode and proceed to step S3. Specifically, the vehicle controller calculates whether the product of the current motor speed and the current motor torque is positive. If yes, the vehicle controller controls the motor to enter the discharge mode. If no, the vehicle controller controls the motor to enter the power generation mode, i.e., the energy recovery mode.

[0048] S3: Receive the current battery SOC value. Specifically, receive the current battery SOC value sent by the battery management system (BMS) through the vehicle controller.

[0049] S4: The vehicle controller determines whether the current battery SOC value is ≥95%. If not, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller. If yes, proceed to step S5.

[0050] S5: Calculate the real-time operating power P of the low-voltage power supply system DC Real-time operating power P of air conditioner compressor EC Specifically, its real-time operating power P is calculated through the low-voltage power supply system. DC The real-time operating power P of the air conditioner compressor is calculated using EC. EC ;

[0051] S6: Calculate the current energy recovery power P using the vehicle controller, P = P DC +P EC ;

[0052] S7: The vehicle controller calculates the motor recovery torque based on the current energy recovery power P and the current motor speed, and sends the motor recovery torque to the motor controller.

[0053] S8: The motor controller performs energy recovery control based on the energy recovery torque sent in step S4 or the motor recovery torque calculated in step S7.

[0054] In one embodiment of the present invention, in step S4, the vehicle controller sends the energy recovery torque data to the motor controller via the CAN bus. Specifically, during the energy recovery process, when the vehicle begins to decelerate or brake, the vehicle's torque sensor, speed sensor, etc., detect the motor's recovery torque value, and then encode this recovery torque value into a format recognizable by the CAN bus protocol. Each sensor then sends this value to the motor controller via the CAN bus.

[0055] In one embodiment of the present invention, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening. The calculation formula is as follows:

[0056] T_rec = T_max * BPO,

[0057] Where T_rec is the energy recovery torque, T_max is the maximum recoverable torque calculated based on the battery's recoverable power and the current motor speed, without considering the brake pedal opening, and BPO is the brake pedal opening, which is used to adjust the energy recovery torque. The battery's recoverable power typically represents the maximum power that the battery can absorb for energy recovery during braking; this value is usually provided by the battery management system (BMS).

[0058] In one embodiment of the present invention, the energy recovery torque can be calibrated through a specific calibration strategy. For example, according to a certain fixed deceleration, the resistance required by the vehicle when decelerating at the fixed deceleration is calculated, and then the motor resistance is calculated according to the vehicle's transmission ratio and tire radius. Then, the motor power required when decelerating is calculated based on the motor resistance. Finally, the motor energy recovery torque of each vehicle speed range is calculated based on the motor power.

[0059] In one embodiment of the present invention, step S6 specifically includes:

[0060] S61: The low-voltage power supply system uses its own collected current I DC and voltage value U DC Calculate the real-time power P of the low-voltage power supply system DC =I DC *U DC The air conditioner compressor uses the current I it collects. EC and voltage value U EC Calculate the real-time power P of the air conditioner compressor. EC =I EC *U EC ;

[0061] S62: The low-voltage power supply system and the air conditioning compressor respectively send their real-time power to the vehicle controller via the CAN bus. The vehicle controller then calculates the current recoverable power: P = P0 DC +P EC .

[0062] In one embodiment of the present invention, based on the current recoverable power P calculated in step S6 and combined with the current motor speed, the motor recovery torque is calculated in reverse. The formula for the reverse calculation is as follows:

[0063] P = Motor recovery torque * Current motor speed / 9550, where 9550 is a constant used to convert the units of torque and speed to the units of power (usually watts); the current recoverable power P represents the electrical energy power that the motor can generate through energy recovery at a specific moment.

[0064] In one embodiment of the present invention, the motor recovery torque value calculated in step S6 is sent to the motor controller via the CAN bus.

[0065] Based on the above design, when the current battery SOC value is <95%, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller; if the SOC value is ≥95%, the real-time operating power P of the low-voltage power supply system is calculated. DC Real-time operating power P of air conditioner compressor EC Then calculate the current energy recovery power P, P = P DC +P EC Based on the current energy recovery power P and the current motor speed, the motor recovery torque is calculated and sent to the motor controller. The motor controller then performs energy recovery control based on the energy recovery torque or the motor recovery torque. By implementing the control scheme of this invention, the vehicle can still perform energy recovery when the battery SOC is ≥ 95%, increasing the vehicle's range and reducing energy consumption. Furthermore, when the battery SOC is ≥ 95%, braking can be performed through energy recovery to prevent battery overcharging and reduce the risk of brake drum overheating.

[0066] This invention also relates to an energy recovery compensation system for an electric vehicle. The energy recovery compensation system includes at least one software functional module, which can be stored in a storage module or embedded in an operating system (OS) in the form of software or firmware. A processing module is used to execute the executable module stored in the storage module, such as the software functional module and computer program included in the energy recovery compensation system. The energy recovery compensation system for the electric vehicle includes:

[0067] The first acquisition module is used to receive the current motor torque and the current motor speed;

[0068] The first determining module is used to calculate whether the product of the current motor speed and the current motor torque is positive. If it is, the motor is controlled to enter the discharge mode; if not, the motor is controlled to enter the power generation mode.

[0069] The second acquisition module is used to receive the current battery SOC value;

[0070] The second determining module is used to determine whether the current battery SOC value is ≥95%. If not, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller. If yes, it calculates the real-time operating power P of the low-voltage power supply system. DC Real-time operating power P of air conditioner compressor EC ;

[0071] The first calculation module is used to calculate the current energy recovery power P, P = P DC +P EC ;

[0072] The second calculation module is used to calculate the motor recovery torque based on the current energy recovery power and the current motor speed, and send the motor recovery torque to the motor controller.

[0073] The execution control module performs energy recovery control based on the energy recovery torque or the motor recovery torque through the motor controller.

[0074] The present invention also relates to an electric vehicle, including a controller, the controller being used to execute the above-described energy recovery compensation method for an electric vehicle, or including the above-described energy recovery compensation system for an electric vehicle.

[0075] This invention also relates to a non-transitory computer-readable storage medium storing a computer program that, when executed by a processor, is implemented to perform the above-described energy recovery compensation method for electric vehicles.

[0076] Based on the above description of the embodiments, those skilled in the art can clearly understand that this application can be implemented by hardware or by using software plus necessary general-purpose hardware platforms. Based on this understanding, the technical solution of this application can be embodied in the form of a software product. This software product can be stored in a non-volatile storage medium (such as CD-ROM, USB flash drive, mobile hard drive, etc.) and includes several instructions to cause a computer device (such as a personal computer, control system, or network device, etc.) to execute the methods described in the various implementation scenarios of this application.

[0077] The above description of the structure, features, and effects of the present invention is based on the embodiments shown in the figures. However, the above are only preferred embodiments of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched by those skilled in the art to form a variety of equivalent solutions without departing from or changing the design concept and technical effects of the present invention. Therefore, the present invention is not limited to the scope of implementation shown in the figures. Any changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments, that do not exceed the spirit covered by the specification and figures, should be within the protection scope of the present invention.

Claims

1. A method for energy recovery and compensation in electric vehicles, characterized in that, Includes the following steps: S1: Receives the current motor torque and current motor speed; S2: Determine whether the product of the current motor speed and the current motor torque is positive. If it is, control the motor to enter the discharge mode. If not, control the motor to enter the power generation mode and proceed to step S3. S3: Receive the current battery SOC value; S4: Determine whether the current battery SOC value is ≥95%. If not, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller. If yes, proceed to step S5. S5: Calculate the real-time operating power P of the low-voltage power supply system DC Real-time operating power P of air conditioner compressor EC ; S6: Calculate the current energy recovery power P, P = P DC +P EC ; S7: Based on the current energy recovery power P and the current motor speed, calculate the motor recovery torque and send the motor recovery torque to the motor controller; S8: Energy recovery control is performed by the motor controller based on the energy recovery torque sent in step S4 or the motor recovery torque calculated in step S7.

2. The energy recovery and compensation method for electric vehicles according to claim 1, characterized in that, In step S4, the vehicle controller sends the energy recovery torque data to the motor controller via the CAN bus.

3. The energy recovery compensation method for electric vehicles according to claim 1, characterized in that, The vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening. The calculation formula is as follows: T_rec = T_max * BPO, Where T_rec is the energy recovery torque, T_max is the maximum recoverable torque calculated based on the battery's recoverable power and the current motor speed without considering the brake pedal opening, and BPO is the brake pedal opening, which is used to adjust the energy recovery torque.

4. The energy recovery compensation method for electric vehicles according to claim 1, characterized in that, Step S6 specifically includes: S61: The low-voltage power supply system uses its own collected current I DC and voltage value U DC Calculate the real-time power P of the low-voltage power supply system DC =I DC *U DC The air conditioner compressor uses the current I it collects. EC and voltage value U EC Calculate the real-time power P of the air conditioner compressor. EC =I EC *U EC ; S62: The low-voltage power supply system and the air conditioning compressor respectively send their real-time power to the vehicle controller via the CAN bus. The vehicle controller calculates the current recoverable power: P = P0 DC +P EC .

5. The energy recovery compensation method for electric vehicles according to claim 4, characterized in that, Based on the current recoverable power P calculated in step S6, and combined with the current motor speed, the motor recovery torque is calculated in reverse. The formula for the reverse calculation is: P = Motor recovery torque * Current motor speed / 9550.

6. The energy recovery compensation method for electric vehicles according to claim 5, characterized in that, The motor recovery torque value calculated in step S6 is sent to the motor controller via the CAN bus.

7. An energy recovery compensation system for an electric vehicle, characterized in that, include: The first acquisition module is used to receive the current motor torque and the current motor speed; The first determining module is used to calculate whether the product of the current motor speed and the current motor torque is positive. If it is, the motor is controlled to enter the discharge mode; if not, the motor is controlled to enter the power generation mode. The second acquisition module is used to receive the current battery SOC value; The second determining module is used to determine whether the current battery SOC value is ≥95%. If not, the vehicle controller calculates the energy recovery torque based on the battery's recyclable power, the current motor speed, and the brake pedal opening, and sends the energy recovery torque data to the motor controller. If yes, it calculates the real-time operating power P of the low-voltage power supply system. DC Real-time operating power P of air conditioner compressor EC ; The first calculation module is used to calculate the current energy recovery power P, P = P DC +P EC ; The second calculation module is used to calculate the motor recovery torque based on the current energy recovery power and the current motor speed, and send the motor recovery torque to the motor controller. The execution control module performs energy recovery control based on the energy recovery torque or the motor recovery torque through the motor controller.

8. An electric vehicle, characterized in that, It includes a controller for performing the energy recovery compensation method for an electric vehicle as described in any one of claims 1-6, or includes the energy recovery compensation system for an electric vehicle as described in claim 7.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program is implemented to perform the energy recovery compensation method for an electric vehicle as described in any one of claims 1-6.

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