A battery control method of a range extended electric vehicle, a storage medium and a vehicle

Abstract

The application discloses a battery control method of a range-extending electric vehicle, a storage medium and a vehicle, and the method comprises the following steps: controlling the vehicle to enter a pure electric mode or a range-extending mode; calculating a driver demand torque T according to vehicle information of the electric vehicle by a vehicle controller; judging whether the vehicle is in a driving state or an energy recovery state according to the demand torque T by a motor controller; the range-extender, the lithium ion battery, the super capacitor battery, the motor controller, the whole machine controller, the high-voltage relay one, the high-voltage relay two and the high-voltage relay three are matched with each other, when the motor is in power output under the working conditions of low temperature and low residual power, the super capacitor is discharged or the range-extender is discharged, so that the acceleration performance of the vehicle is prevented from being greatly attenuated due to the decline of the discharge capacity of the lithium ion battery; when the estimated energy recovery power is too large or the energy recovery power and the range-extender power are too large, the super capacitor battery is charged, so that the lithium ion battery is prevented from being damaged due to overcharging.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle technology, specifically to a battery control method, storage medium, and vehicle for a range-extended electric vehicle. Background Technology

[0002] Range-extended electric vehicles (REEVs) are typically equipped with one or more electric motors and a fuel-powered range extender, which consists of an engine and a generator system. The vehicle is directly driven by the electric motor; the engine does not participate in driving and there are no mechanical devices such as clutches or gearboxes. When the battery power is insufficient or the electrical energy it provides cannot meet the motor's needs, the engine starts and drives the generator to produce electricity. This electricity can be used to drive the motor or to charge the battery.

[0003] Currently, range-extended electric vehicles are generally equipped with lithium-ion battery systems. Lithium-ion batteries are a type of rechargeable battery that primarily functions by the movement of lithium ions between the positive and negative electrodes. Compared to other types of batteries, they have advantages such as high energy density, good safety performance, and long cycle life. However, lithium-ion batteries also have significant disadvantages in certain aspects.

[0004] Firstly, lithium-ion batteries have poor discharge performance at low temperatures or low charge levels. This causes a significant decrease in vehicle acceleration performance in cold environments or when the remaining charge is insufficient. Even if the range extender is engaged at this time, the combined power of the range extender and the battery may not be able to meet the motor's needs. Increasing the workload of the range extender will lead to a decrease in its efficiency and an increase in fuel consumption. Using a higher power range extender will lead to an increase in energy consumption and cost.

[0005] Most electric vehicles nowadays are equipped with energy recovery systems, which convert the kinetic energy generated during driving into electrical energy to recharge the battery pack and extend the driving range. In cold environments, due to the limited discharge performance of the battery, the range extender and battery will simultaneously supply power to the motor. When the vehicle switches from acceleration to energy recovery mode, the generator power cannot decrease quickly due to engine inertia and other reasons, and the motor generates electrical energy through energy recovery. At this time, the electrical energy generated by the range extender and the electrical energy recovered by the motor will simultaneously charge the battery system, causing the battery system to be overcharged in a short period of time, thus damaging the battery. Even when the battery has a large remaining charge, the simultaneous charging of the battery by the motor and range extender will also cause overcharging.

[0006] Supercapacitors, also known as electrochemical capacitors, are power sources with unique properties that fall between traditional capacitors and batteries. They primarily store energy through double-layer capacitance and redox pseudocapacitance. Compared to lithium-ion batteries, supercapacitors offer better high and low temperature performance and higher charge / discharge rates. However, due to their lower energy density, supercapacitors have not been widely adopted in the electric vehicle (EV) field. Currently, supercapacitors in EVs are generally only used to provide a large driving current for rapid vehicle start-up and high-power applications. Supercapacitors are not being fully utilized, and there remains a risk of significant performance degradation due to decreased lithium-ion electron discharge capacity and overcharging of lithium-ion batteries. Summary of the Invention

[0007] The purpose of this invention is to improve and innovate upon the shortcomings and problems existing in the prior art, and to provide a battery control method, storage medium, and vehicle for a range-extended electric vehicle.

[0008] According to a first aspect of the present invention, the present invention provides a battery control method for a range-extended electric vehicle, specifically comprising:

[0009] The driver issues a command to put the vehicle into pure electric mode or range-extended mode;

[0010] The vehicle controller calculates the driver's required torque T based on the electric vehicle information and sends the required torque T to the motor controller. The motor controller determines whether the vehicle is in driving mode or energy recovery mode based on the required torque T.

[0011] When the vehicle enters pure electric mode and is in driving mode, the vehicle controller estimates the driving power P and compares it with the maximum discharge power P of the lithium battery. A The size of the drive power P determines whether to use a lithium-ion battery or a supercapacitor battery to power the motor controller.

[0012] When the vehicle enters range-extended mode and is in driving state, the vehicle controller estimates the driving power P and compares the actual power generation P2 of the range extender with the driving power P. When the actual power generation P2 of the range extender is less than the driving power P, the lithium-ion battery or supercapacitor battery is selected to power the motor controller in conjunction with the range extender. When the actual power generation P2 of the range extender is greater than or equal to the driving power P, the lithium-ion battery or supercapacitor battery is selected to charge.

[0013] When the vehicle enters pure electric mode and is in energy recovery mode, the vehicle controller estimates the energy recovery power P and compares it with the maximum charging power P of the lithium-ion battery. B Based on the estimated energy recovery power P, choose whether to charge the lithium-ion battery or the supercapacitor battery.

[0014] When the vehicle enters range-extending mode and is in energy recovery mode, the vehicle controller estimates the energy recovery power P and compares the sum of the estimated energy recovery power P and the actual power generated by the range extender P2 with the maximum charging power P of the lithium-ion battery. B The size allows you to choose whether to charge a lithium-ion battery or a supercapacitor.

[0015] As can be seen from the above technical solution, the present invention compares the relative magnitudes of drive power, energy recovery power, maximum charging and discharging power of lithium ions, and actual power generation of the range extender. Specifically, it estimates drive power and energy recovery power based on the required torque T and motor speed r, thereby precisely guiding the overall controller to manage the charging and discharging logic of the range extender and the two battery packs. This minimizes the risk of significant performance degradation due to decreased lithium ion battery discharge capacity and damage to the lithium ion battery due to overcharging. It also solves the problem of the power supply system failing to meet motor power requirements and the issue of lithium ion battery overcharging in certain situations.

[0016] A further solution is that the specific control method for when the vehicle enters pure electric mode and is in driving state is as follows:

[0017] Switch the high-voltage relay three to the off state. The high-voltage relay three is used to control the on / off state of the high-voltage circuit between the motor controller and the range extender.

[0018] The vehicle controller estimates the drive power P based on the required torque T and motor speed r, combined with the power of other electrical appliances.

[0019] The battery management system (BMS1) of a lithium-ion battery determines the maximum discharge power (P) of the lithium-ion battery based on its parameters. A And send it to the overall controller, so that the overall controller can compare P and P A Size;

[0020] When judging P>P A When the controller closes high-voltage relay two and opens high-voltage relay one, the supercapacitor battery system supplies power to the motor controller; when it is determined that P≤P A When high voltage relay 1 is closed, high voltage relay 2 is opened, and the lithium-ion battery system supplies power to the motor controller. High voltage relay 1 is used to control the on / off of the high voltage circuit between the motor controller and the lithium-ion battery. High voltage relay 2 is used to control the on / off of the high voltage circuit between the motor controller and the supercapacitor battery.

[0021] A further solution is that the specific control method for when the vehicle enters range-extending mode and is in driving state is as follows:

[0022] Switch the high-voltage relay three to the closed state and request the range extender to generate electricity. The range extender feeds back the actual power generation power P2 to the vehicle controller. The high-voltage relay three is used to control the on and off of the high-voltage circuit between the motor controller and the range extender;

[0023] The vehicle controller estimates the driving power P according to the required torque T, the motor speed r, and in combination with the power of other electrical appliances;

[0024] When it is judged that P2 < P, the battery management system BMS1 of the lithium-ion battery judges the maximum discharge power P of the lithium-ion battery according to the lithium-ion battery parameters A and sends it to the vehicle controller for the vehicle controller to judge whether P is greater than P A + P2. If P > P A + P2, the vehicle controller closes the high-voltage relay two and disconnects the high-voltage relay one, and the supercapacitor battery and the range extender jointly provide electric energy for the motor; if P ≤ P A + P2, the vehicle controller compares the remaining capacity S1 of the lithium-ion battery with the remaining capacity S2 of the supercapacitor battery. If it is judged that S1 > S2, the vehicle controller closes the high-voltage relay one and disconnects the high-voltage relay two. If S1 ≤ S2, the vehicle controller closes the high-voltage relay two and disconnects the high-voltage relay one;

[0025] When it is judged that P2 ≥ P, the battery management system BMS1 of the lithium-ion battery judges the maximum charging power P of the lithium-ion battery according to the lithium-ion battery parameters B and sends it to the vehicle controller for the vehicle controller to judge whether P is greater than P B + P2. If P2 > P + P B , then the vehicle controller closes the high-voltage relay two and disconnects the high-voltage relay one. If P2 ≤ P + P B , the vehicle controller compares the remaining capacity S1 of the lithium-ion battery with the remaining capacity S2 of the supercapacitor battery. If it is judged that S1 > S2, the vehicle controller controls to close the high-voltage relay two and disconnect the high-voltage relay one. If S1 ≤ S2, the vehicle controller controls to close the high-voltage relay one and disconnect the high-voltage relay two; The high-voltage relay one is used to control the on and off of the high-voltage circuit between the motor controller and the lithium-ion battery; The high-voltage relay two is used to control the on and off of the high-voltage circuit between the motor controller and the supercapacitor battery.

[0026] A further solution is that the specific control method when the vehicle enters the pure electric mode and is in the energy recovery state is as follows:

[0027] Switch the high-voltage relay three to the open state. The high-voltage relay three is used to control the on and off of the high-voltage circuit between the motor controller and the range extender;

[0028] The vehicle controller estimates the energy recovery power P based on the required torque T, motor speed r, and the power of other electrical appliances.

[0029] The battery management system (BMS1) of a lithium-ion battery determines the maximum charging power P of the lithium-ion battery based on the battery parameters. B Used for vehicle controller to compare P and P B The size when judging P>P B The vehicle controller closes high-voltage relay two and opens high-voltage relay one. When P ≤ P... B The vehicle controller controls the closing of high-voltage relay one and the opening of high-voltage relay two. High-voltage relay one is used to control the connection and disconnection of the high-voltage circuit between the motor controller and the lithium-ion battery; while high-voltage relay two is used to control the connection and disconnection of the high-voltage circuit between the motor controller and the supercapacitor battery.

[0030] A further solution is that the specific control method for when the vehicle enters range-extending mode and is in energy recovery state is as follows:

[0031] Switch the high-voltage relay three to the closed state and request the range extender to generate electricity. The range extender feeds back the actual generated power P2 to the vehicle controller. The high-voltage relay three is used to control the on / off state of the high-voltage circuit between the motor controller and the range extender.

[0032] The vehicle controller estimates the energy recovery power P based on the required torque T, motor speed r, and the power of other electrical appliances.

[0033] The battery management system (BMS1) of a lithium-ion battery determines the maximum charging power P of the lithium-ion battery based on the battery parameters. B Used for vehicle controller to compare P+P2 and P B The size of P when determining P + P2 > P B When the vehicle controller closes high-voltage relay two and opens high-voltage relay one, the system determines that P + P2 ≤ P. B At that time, the vehicle controller compares the remaining capacity S1 of the lithium-ion battery with the remaining capacity S2 of the supercapacitor battery. If it is determined that S1>S2, the vehicle controller controls the closing of high-voltage relay 2 and the opening of high-voltage relay 1. If S1≤S2, the vehicle controller controls the closing of high-voltage relay 1 and the opening of high-voltage relay 2. High-voltage relay 1 is used to control the on / off of the high-voltage circuit between the motor controller and the lithium-ion battery. High-voltage relay 2 is used to control the on / off of the high-voltage circuit between the motor controller and the supercapacitor battery.

[0034] A further option is that the lithium-ion battery parameters include the lithium-ion battery temperature and the remaining capacity of the lithium-ion battery.

[0035] A further solution is that the estimated drive power QUOTE T is the required torque, r is the motor speed, and P is the torque required. F The power of other electrical accessories, including the air conditioning system and DC-DC module, is T, where the required torque T≥0.

[0036] A further option is that the estimated energy recovery power QUOTE T is the required torque, r is the motor speed, and P is the torque required. F The power of the remaining electrical accessories, including the air conditioning system and DC-DC module, is T, where the required torque T < 0.

[0037] According to a second aspect of the present invention, a storage medium is provided having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described above.

[0038] According to a third aspect of the present invention, a vehicle is provided, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the method described above.

[0039] Compared with the prior art, the beneficial effects of the present invention are: (1) The present invention, through the cooperation of the range extender, lithium-ion battery, supercapacitor battery, motor controller, whole machine controller, high voltage relay one, high voltage relay two and high voltage relay three, enables the lithium-ion battery to discharge under low temperature and low residual capacitance conditions, and when the motor outputs power, the supercapacitor discharges or the range extender discharges in combination, so as to avoid the vehicle acceleration performance from being greatly reduced due to the decrease in the discharge capacity of the lithium-ion battery; in addition, when the motor recovers energy, when the estimated energy recovery power is too large or the energy recovery power is too large compared with the power generated by the range extender, the whole machine controller closes high voltage relay two and opens high voltage relay one to charge the supercapacitor battery, so as to avoid the lithium-ion battery from being damaged due to overcharging;

[0040] (2) This invention compares the relative magnitudes of drive power, energy recovery power, maximum charging and discharging power of lithium ions and actual power generation of the range extender. Drive power and energy recovery power are estimated based on the required torque T and motor speed r. Maximum charging and discharging power of lithium ions is determined based on the temperature and remaining capacity of the lithium ion battery. This provides precise guidance to the whole machine controller to control the charging and discharging logic of the range extender and the two battery packs, thereby minimizing the reduction in vehicle acceleration performance due to the decrease in the discharge capacity of the lithium ion battery and the damage to the lithium ion battery due to overcharging.

[0041] (3) By comparing the remaining capacity of the lithium-ion battery with that of the supercapacitor battery, the present invention can further accurately guide the charging and discharging logic of the two battery packs, thereby making full use of the remaining capacity of the lithium-ion battery and the supercapacitor battery and improving energy utilization efficiency. Since the maximum charging and discharging power of lithium-ion batteries is related to the remaining capacity of lithium-ion batteries, it can also avoid the significant decline in vehicle acceleration performance due to the decrease in the discharge capacity of lithium-ion batteries and the damage caused by overcharging of lithium-ion batteries. Attached Figure Description

[0042] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0043] Figure 1 This is a hardware connection schematic diagram of the present invention;

[0044] Figure 2 This is a diagram showing the functional interaction relationships of the components in this invention;

[0045] Figure 3 This is the logic diagram for determining the driving state and energy recovery state of the present invention;

[0046] Figure 4 This is the logic diagram for pure electric mode and range-extended mode of the present invention;

[0047] Figure 5 This is the VCU control logic diagram in the pure electric mode of the driving state of this invention;

[0048] Figure 6 This is the VCU control logic diagram in the extended range mode of the drive state of this invention;

[0049] Figure 7 This is the VCU control logic diagram in the pure electric mode of the energy recovery state of this invention;

[0050] Figure 8 This is the VCU control logic diagram for the energy recovery state range extension mode of this invention. Detailed Implementation

[0051] To make the objectives, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0052] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0054] Example 1

[0055] Figure 1 The diagram shows the hardware schematic of this hybrid battery system. The corresponding abbreviations and terms are defined below:

[0056] abbreviations Full English name Chinese abbreviation VCU Vehicle Control Unit Vehicle controller BMS Battery Management System Battery Management System MCU Motor Control Unit motor controller

[0057] In terms of mechanical transmission, the motor is connected to the wheels through a transmission system, which includes a reducer, differential, and half-shafts. The motor controller is responsible for controlling the motor's power output or energy recovery. It is connected to the motor via high-voltage and low-voltage control lines. The lithium-ion battery system, supercapacitor battery system, and fuel range extender are each connected to the MCU via high-voltage lines, supplying power to the MCU. Three high-voltage relays control the on / off state of the three high-voltage circuits: from the lithium-ion battery system to the MCU, from the supercapacitor battery system to the MCU, and from the fuel range extender to the MCU. These three relays are connected to the VCU via a low-voltage control circuit, and their on / off states are controlled by the VCU. BMS1 is the battery management system for the lithium-ion battery, responsible for managing and protecting the lithium-ion battery system. BMS2 is the battery management system for the supercapacitor, responsible for managing and protecting the supercapacitor battery system. The MCU, BMS1, BMS2, and fuel range extender are each connected to the VCU via a low-voltage control circuit and interact via CAN communication.

[0058] Please see Figure 2 To define the division of responsibilities and interactions among the various components, the VCU (Vehicle Control Unit) first calculates the driver's required torque T based on information such as accelerator and brake pedal openings, current vehicle speed, and driving mode. This torque is then transmitted to the MCU (Microcontroller Unit) via CAN communication. The MCU, based on the driver's required torque, controls the motor to output power or recover electrical energy through torque control mode. The methods for calculating the required torque and the MCU control methods are existing technologies and will not be described in detail in this patent.

[0059] The MCU collects the real-time motor speed r and sends it to the VCU. The VCU can estimate the motor power P by combining the required torque T, the motor speed r, and the power of other electrical appliances.

[0060] BMS1 and BMS2 can calculate the remaining capacity (SOC) of the battery pack by calculating the total battery charge and the used charge. BMS1 can calculate the maximum allowable charging power and maximum allowable discharging power of the battery pack at this time based on the ambient temperature, cell temperature and remaining SOC, and send the SOC, maximum charging power and maximum discharging power to VCU via CAN communication. The calculation of SOC and maximum charging and discharging power are existing technologies and will not be described in detail in this patent.

[0061] The VCU can control the on / off state of high-voltage relays one, two, and three via a low-voltage control circuit. High-voltage relays one and two will not be simultaneously on or off. In pure electric mode, high-voltage relay three is off, and when high-voltage relay one is closed, the lithium-ion battery powers the MCU. When high-voltage relay two is closed, the supercapacitor battery powers the MCU. In range-extender mode, the range extender starts, and high-voltage relay three closes. When high-voltage relay one is closed, the circuit of the range extender, lithium-ion battery, and MCU is connected. The range extender and lithium-ion battery can either work together to power the MCU, or the range extender can power the MCU alone, with any remaining energy flowing into the lithium-ion battery. Alternatively, all the energy generated by the range extender and the energy recovered by the MCU can be used to charge the lithium-ion battery. When high-voltage relay two is closed, the circuit of the range extender, supercapacitor battery, and MCU is connected. Again, the range extender and supercapacitor battery can either work together to power the MCU, or the range extender can power the MCU alone, with any remaining energy flowing into the supercapacitor battery. Alternatively, all the energy generated by the range extender and the energy recovered by the MCU can be used to charge the supercapacitor battery.

[0062] The VCU can send engine start / stop commands and power generation commands to the range extender via CAN communication. The range extender responds to the engine start / stop commands and power generation commands sent by the VCU, collects the actual power generation, and sends it back to the VCU.

[0063] Please see Figure 3 The logic for determining the driving state and energy recovery state first determines whether the vehicle is in driving or energy recovery state based on the driver's required torque T obtained from the VCU. When the required torque T ≥ 0, the vehicle is in driving state, and the power supply system sends electrical energy to the MCU to drive the motor. When the required torque T < 0, the vehicle is in energy recovery state, and the motor converts mechanical energy into electrical energy, which is then charged into the battery through the MCU.

[0064] The logic for determining range-extended mode and pure electric mode is as follows: Figure 4As shown, the driver issues a command to enter range-extended mode or pure electric mode via a switch or other interactive method. In range-extended mode, the range extender starts working and combines with the battery to provide power to the vehicle. In pure electric mode, the range extender stops, and the vehicle is powered solely by the battery.

[0065] According to a first aspect of the present invention, a battery control method for a range-extended electric vehicle is provided:

[0066] Based on the vehicle's mode and state, there are four operating conditions: pure electric mode in driving state, range-extended mode in driving state, pure electric mode in energy recovery state, and range-extended mode in energy recovery state. The following sections will explain each of these four operating conditions.

[0067] Control method in pure electric mode of driving state as follows Figure 5 As shown, it specifically includes:

[0068] S101: First, in pure electric mode, the high-voltage relay three is in the open state, the range extender is turned off and does not participate in high-voltage power supply, then proceed to the next step;

[0069] S102: The VCU analyzes the driver's required torque T by the accelerator and brake pedal opening, vehicle speed, etc., and sends the required torque to the MCU. The MCU responds to the required torque and controls the motor to output power. At the same time, the MCU collects the motor speed r and sends it to the VCU to proceed to the next step.

[0070] S103: The VCU uses the required torque T and motor speed r according to the formula:

[0071]

[0072] P F The power of other electrical accessories, including the air conditioning system, DC-DC module, etc., is P, which is the estimated drive power of the whole vehicle. Proceed to the next step.

[0073] S104: The Battery Management System (BMS1) for lithium-ion batteries determines the maximum discharge power P of the battery based on factors such as battery temperature and remaining SOC. A And send it to VCU, VCU compares P and P A The size when judging P>P A When the maximum discharge power of the lithium-ion battery is less than the estimated drive power, in order to protect the lithium-ion battery, the VCU controls the closing of high-voltage relay two and the opening of high-voltage relay one through the low-voltage circuit. At this time, the supercapacitor battery system supplies power to the MCU. When it is determined that P≤P A When the lithium-ion battery is sufficient to meet the power demand of the motor, the high-voltage relay one is closed and the high-voltage relay two is opened through the low-voltage circuit control. At this time, the lithium-ion battery system supplies power to the MCU, and the process ends.

[0074] S105: Jump to the start state and repeat the above calculation process. The calculation period is above 50 Hz to ensure rapid response to the impact of real-time power demand changes on the system.

[0075] It should be noted here that when selecting a supercapacitor battery system, both the maximum discharge power and the maximum charge power of the battery need to exceed the sum of the maximum drive power of the motor, the maximum energy recovery power of the motor, and the power generation power of the range extender.

[0076] The control method in the drive state range extender mode is as Figure 6 shown, specifically including:

[0077] S201: In the range extender mode, the VCU needs to close high-voltage relay three, send a start range extender instruction, and request the range extender to generate electricity at a certain power P1. P1 is a calibratable value, and the power range with the highest working efficiency needs to be selected for assignment considering the working efficiency of the range extender assembly comprehensively;

[0078] S202: The range extender receives the start request sent by the VCU, starts the engine, and generates electricity at power P1. However, since there is a large deviation between the actual power of the engine and the requested power, the range extender needs to collect the actual power generation P2 and send it to the VCU;

[0079] S203: The VCU analyzes the driver's demand torque T through the throttle and brake pedal openings, vehicle speed, etc., and sends this demand torque to the MCU. The MCU responds to this demand torque and controls the motor for power output. At the same time, the MCU collects the motor speed r and sends it to the VCU for the next step;

[0080] S204: The VCU calculates according to the formula based on the demand torque T and the motor speed r:

[0081]

[0082] P F is the power of other electrical accessories, including the air conditioning system, DCDC module, etc. P is the estimated drive power of the vehicle, and proceed to the next step;

[0083] S205: Determine whether the range extender power generation P2 is greater than the drive power P. If P2 < P, it means that the electricity generated by the range extender is not enough to meet the power consumption demand of the motor. At this time, the range extender and the battery system need to jointly provide electrical energy for the MCU, and proceed to S206.1; if P2 ≥ P, it means that the electricity generated by the range extender exceeds the electricity consumed by the motor. At this time, in addition to providing electrical energy for the MCU, the excess electricity of the range extender needs to be charged into the battery system, and proceed to S207.1;

[0084] S206.1: The Battery Management System (BMS1) of a lithium-ion battery determines the maximum discharge power P of the battery pack based on factors such as battery temperature and remaining SOC. A and maximum charging power P B And send it to the VCU, where the VCU determines whether P is greater than P. A +P2, if P>P A +P2 indicates that the combined power from the lithium-ion battery and range extender cannot meet the motor's requirements. In this case, the VCU needs to close high-voltage relay two and open high-voltage relay one, using the supercapacitor battery system and range extender to jointly provide power to the MCU, ending the process. If P≤P A +P2 then proceeds to the next step;

[0085] S206.2: The lithium-ion battery management system BMS1 calculates the remaining available SOC S1, and the supercapacitor battery management system BMS2 calculates the remaining available SOC S2 and sends them to the VCU. The VCU compares S1 and S2. If S1 > S2, the energy in the lithium-ion battery is used first. At this time, the VCU controls the closing of high-voltage relay one and the opening of high-voltage relay two. The lithium-ion battery and the range extender jointly provide power to the MCU. If S1 ≤ S2, the energy in the supercapacitor battery is used first. At this time, the VCU controls the closing of high-voltage relay two and the opening of high-voltage relay one. The supercapacitor battery and the range extender jointly provide power to the MCU. End.

[0086] S207.1: VCU determines P2 and P+P B The size, if P2>P+P B This indicates that the remaining power of the range extender after deducting the power consumed by the motor still exceeds the maximum charging power of the lithium-ion battery. If this power were to be charged into the lithium-ion battery at this point, it would cause overcharging and damage. Therefore, the VCU controls the closing of high-voltage relay two and the opening of high-voltage relay one, allowing the range extender to supply the MCU while the remaining power charges the supercapacitor battery system, thus ending the process. If P2 ≤ P + P B Then proceed to the next step;

[0087] S207.2: The VCU compares the values ​​of S1 and S2. If S1 > S2, it indicates that there is more energy in the lithium-ion battery. In this case, the supercapacitor battery system is charged first. The VCU controls the closing of high-voltage relay 2 and the opening of high-voltage relay 1, so that the energy generated by the range extender is reduced by the part consumed by the motor, and the remaining energy is charged into the supercapacitor battery. If S1 ≤ S2, it indicates that there is less energy in the lithium-ion battery. In this case, the lithium-ion battery is charged first. The VCU controls the closing of high-voltage relay 1 and the opening of high-voltage relay 2, so that the energy generated by the range extender is reduced by the part consumed by the motor, and the remaining energy is charged into the lithium-ion battery. End.

[0088] S208: Jump to the start state and repeat the above calculation process. The calculation cycle is above 50Hz to ensure that the system can quickly respond to the impact of real-time power demand changes.

[0089] Control method in pure electric mode with energy recovery as follows Figure 7 As shown, it specifically includes:

[0090] S301: First, in pure electric mode, the high-voltage relay three is in the open state, the range extender is turned off and does not participate in high-voltage power supply, proceed to the next step;

[0091] S302: The VCU analyzes the driver's required torque T by the accelerator and brake pedal opening, vehicle speed, etc., and sends the required torque to the MCU. The MCU responds to the required torque and controls the motor to perform energy recovery. At the same time, the MCU collects the motor speed r and sends it to the VCU to proceed to the next step.

[0092] S303: The VCU uses the required torque T and motor speed r according to the formula:

[0093]

[0094] P F The power of other electrical accessories, including the air conditioning system, DC-DC module, etc., is P, which is the estimated energy recovery power of the whole vehicle. Proceed to the next step.

[0095] S304: The Battery Management System (BMS1) for lithium-ion batteries determines the maximum charging power P of the battery based on factors such as battery temperature and remaining SOC. B And send it to VCU, VCU compares P and P B The size when judging P>P B At this time, the high-voltage relay 2 is closed and the high-voltage relay 1 is opened by controlling the low-voltage circuit. At this time, the electrical energy generated by energy recovery is charged into the supercapacitor battery system. When it is determined that P≤P B The high-voltage relay one is closed and the high-voltage relay two is opened by controlling the low-voltage circuit. At this time, the electrical energy generated by energy recovery is charged into the lithium-ion battery system, and the process ends.

[0096] S305: Jump to the start state and repeat the above calculation process. The calculation cycle is above 50Hz to ensure a rapid response to the impact of real-time power demand changes on the system.

[0097] Control method in energy recovery state range extension mode as follows Figure 8 As shown, it specifically includes:

[0098] S401: In range-extending mode, the VCU needs to close the high-voltage relay three, send the start command for the range extender and request the range extender to generate electricity at a certain power P1. P1 is a calibrable value. The working efficiency of the range extender assembly needs to be taken into account, and the power range with the highest working efficiency should be selected for assignment.

[0099] S402: The range extender receives the start request sent by the VCU and starts the engine, generating electricity with power P1. However, because there is a large deviation between the actual power of the engine and the requested power, the range extender needs to collect the actual generated power P2 and send it to the VCU.

[0100] S403: The VCU analyzes the driver's required torque T by the accelerator and brake pedal opening, vehicle speed, etc., and sends the required torque to the MCU. The MCU responds to the required torque and controls the motor to perform energy recovery. At the same time, the MCU collects the motor speed r and sends it to the VCU to proceed to the next step.

[0101] S404: The VCU uses the required torque T and motor speed r according to the formula:

[0102]

[0103] P F The power of other electrical accessories, including the air conditioning system, DC-DC module, etc., is P, which is the estimated energy recovery power of the whole vehicle. Proceed to the next step.

[0104] S405: The Battery Management System (BMS1) for lithium-ion batteries determines the maximum charging power P of the battery pack based on factors such as battery temperature and remaining SOC. B And send it to the VCU, the VCU determines whether P+P2 is equal to P. B The size, when P + P2 > P B When the combined power of the range extender's generator and energy recovery exceeds the maximum charging power of the lithium-ion battery, there is a risk of overcharging. Therefore, the VCU controls the closing of high-voltage relay two and the opening of high-voltage relay one, allowing electrical energy to be charged into the supercapacitor battery system, thus ending the process. If P + P2 ≤ P B Then proceed to the next step;

[0105] S406: The VCU compares S1 and S2. If S1 > S2, it indicates that the lithium-ion battery has more energy. In this case, the supercapacitor battery system is charged first. The VCU controls the closing of high-voltage relay two and the opening of high-voltage relay one, allowing energy to be charged into the supercapacitor battery. If S1 ≤ S2, it indicates that the lithium-ion battery has less energy. In this case, the lithium-ion battery is charged first. The VCU controls the closing of high-voltage relay one and the opening of high-voltage relay two, allowing energy to be charged into the lithium-ion battery, and the process ends.

[0106] S407: Jump to the start state and repeat the above calculation process. The calculation cycle is above 50Hz to ensure that the system can quickly respond to the impact of real-time power demand changes.

[0107] Example 2

[0108] A storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the method described in Example 1.

[0109] Example 3

[0110] A vehicle includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, performs the steps of the method described in Embodiment 1.

[0111] It should be noted that the control method involved in this patent can be applied not only to lithium-ion battery and supercapacitor battery systems, but also to battery systems with the same or similar performance characteristics. Among them, lithium-ion batteries can be replaced by nickel-metal hydride batteries, sodium-ion batteries or other batteries with similar performance characteristics, and supercapacitor batteries can be replaced by ordinary capacitors, high-power lithium-ion batteries or other batteries with similar performance characteristics.

[0112] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.

[0113] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example.

[0114] Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. The reference to "embodiment" herein means that a specific feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily indicate the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0115] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A battery control method for a range-extended electric vehicle, characterized in that, Specifically, it includes: The driver issues a command to put the vehicle into pure electric mode or range-extended mode; The vehicle controller calculates the driver's required torque T based on the electric vehicle information and sends the required torque T to the motor controller. The motor controller determines whether the vehicle is in driving mode or energy recovery mode based on the required torque T. When the vehicle enters the pure electric mode and is in the driving state, the vehicle controller estimates the driving power P, compares the maximum discharge power P of the lithium battery with the estimated driving power P, and selects the lithium ion battery or the super capacitor battery to supply power to the motor controller. A and the estimated driving power P, and selects the lithium ion battery or the super capacitor battery to supply power to the motor controller. When the vehicle enters range-extended mode and is in driving mode, the vehicle controller estimates the driving power P and compares the actual power generation P2 of the range extender with the estimated driving power P. When the actual power generation P2 of the range extender is less than the estimated driving power P, the range extender is selected to supply power to the motor controller in conjunction with the lithium-ion battery or the supercapacitor battery. When the actual power generation P2 of the range extender is greater than or equal to the estimated driving power P, the lithium-ion battery or the supercapacitor battery is selected to be charged. When the vehicle enters the pure electric mode and is in the energy recovery state, the vehicle controller estimates the energy recovery power P, compares the maximum charging power P of the lithium ion battery with the estimated energy recovery power P, and selects whether to charge the lithium ion battery or the super capacitor battery. B and the estimated energy recovery power P, and selects whether to charge the lithium ion battery or the super capacitor battery. When the vehicle enters the range extending mode and is in the energy recovery state, the vehicle controller estimates the energy recovery power P, and compares the sum of the estimated energy recovery power P and the actual power generation power P2 of the range extender with the maximum charging power P B of the lithium ion battery, and selects whether to charge the lithium ion battery or the super capacitor battery.

2. The battery control method for a range-extended electric vehicle according to claim 1, characterized in that, The specific control method for when the vehicle enters pure electric mode and is in driving state is as follows: Switch the high-voltage relay three to the off state. The high-voltage relay three is used to control the on / off state of the high-voltage circuit between the motor controller and the range extender. The vehicle controller estimates the drive power P based on the required torque T and motor speed r, combined with the power of other electrical appliances. The battery management system (BMS1) of a lithium-ion battery determines the maximum discharge power (P) of the lithium-ion battery based on its parameters. A And send it to the vehicle controller, so that the vehicle controller can compare P and P A Size; When judging P>P A At this time, the vehicle controller closes high-voltage relay two and opens high-voltage relay one, and the supercapacitor battery system supplies power to the motor controller; When determining P≤P A At the same time, high voltage relay one is closed and high voltage relay two is opened, and the lithium-ion battery system supplies power to the motor controller; One of the high-voltage relays is used to control the on / off state of the high-voltage circuit between the motor controller and the lithium-ion battery. High-voltage relay 2 is used to control the on / off state of the high-voltage circuit between the motor controller and the supercapacitor battery.

3. The battery control method for a range-extended electric vehicle according to claim 1, characterized in that, The specific control method for when the vehicle enters range-extending mode and is in driving state is as follows: Switch the high-voltage relay three to the closed state and request the range extender to generate electricity. The range extender feeds back the actual generated power P2 to the vehicle controller. The high-voltage relay three is used to control the on / off state of the high-voltage circuit between the motor controller and the range extender. The vehicle controller estimates the drive power P based on the required torque T and motor speed r, combined with the power of other electrical appliances. When it is judged that P2 < P, the battery management system BMS1 of the lithium-ion battery determines the maximum discharge power P of the lithium-ion battery according to the lithium-ion battery parameters A , and sends it to the vehicle controller, which is used by the vehicle controller to judge whether P is greater than P A +P2. If P > P A +P2, the vehicle controller closes the second high-voltage relay and disconnects the first high-voltage relay, and the supercapacitor battery and the range extender jointly provide electrical energy for the motor; If P≤P A +P2, the vehicle controller compares the remaining capacity S1 of the lithium-ion battery with the remaining capacity S2 of the supercapacitor battery. If it is determined that S1>S2, the vehicle controller closes high-voltage relay one and opens high-voltage relay two. If S1≤S2, the vehicle controller closes high-voltage relay two and opens high-voltage relay one. When it is determined that P2≥P, the battery management system (BMS1) of the lithium-ion battery determines the maximum charging power P of the lithium-ion battery based on the lithium-ion battery parameters. B And send it to the vehicle controller, so that the vehicle controller can determine whether P is greater than P. B +P2, if P>P2+P B Then the vehicle controller closes high-voltage relay two and opens high-voltage relay one. If P≤P2+P B The vehicle controller compares the remaining capacity S1 of the lithium-ion battery with the remaining capacity S2 of the supercapacitor battery. If it is determined that S1>S2, the vehicle controller controls the high-voltage relay 2 to close and the high-voltage relay 1 to open. If S1≤S2, the vehicle controller controls the high-voltage relay 1 to close and the high-voltage relay 2 to open. One of the high-voltage relays is used to control the on / off state of the high-voltage circuit between the motor controller and the lithium-ion battery. High-voltage relay 2 is used to control the on / off state of the high-voltage circuit between the motor controller and the supercapacitor battery.

4. The battery control method for a range-extended electric vehicle according to claim 1, characterized in that, The specific control method for when the vehicle enters pure electric mode and is in energy recovery state is as follows: Switch the high-voltage relay three to the off state. The high-voltage relay three is used to control the on / off state of the high-voltage circuit between the motor controller and the range extender. The vehicle controller estimates the energy recovery power P based on the required torque T, motor speed r, and the power of other electrical appliances. The battery management system (BMS1) of a lithium-ion battery determines the maximum charging power P of the lithium-ion battery based on the battery parameters. B Used for vehicle controller to compare P and P B The size when judging P>P B The vehicle controller closes high-voltage relay two and opens high-voltage relay one. When P ≤ P... B The vehicle controller controls the closing of high-voltage relay one and the opening of high-voltage relay two. High-voltage relay one is used to control the connection and disconnection of the high-voltage circuit between the motor controller and the lithium-ion battery. High-voltage relay 2 is used to control the on / off state of the high-voltage circuit between the motor controller and the supercapacitor battery.

5. The battery control method for a range-extended electric vehicle according to claim 1, characterized in that, The specific control method for when the vehicle enters range-extending mode and is in energy recovery state is as follows: Switch the high-voltage relay three to the closed state and request the range extender to generate electricity. The range extender feeds back the actual generated power P2 to the vehicle controller. The high-voltage relay three is used to control the on / off state of the high-voltage circuit between the motor controller and the range extender. The vehicle controller estimates the energy recovery power P based on the required torque T, motor speed r, and the power of other electrical appliances. The battery management system (BMS1) of a lithium-ion battery determines the maximum charging power P of the lithium-ion battery based on the battery parameters. B Used for vehicle controller to compare P+P2 and P B The size of P when determining P + P2 > P B When the vehicle controller closes high-voltage relay two and opens high-voltage relay one, the system determines that P + P2 ≤ P. B When the vehicle controller compares the remaining capacity S1 of the lithium-ion battery with the remaining capacity S2 of the supercapacitor battery, if it determines that S1>S2, the vehicle controller controls the closing of high-voltage relay 2 and the opening of high-voltage relay 1. If S1≤S2, the vehicle controller controls the closing of high-voltage relay 1 and the opening of high-voltage relay 2. One of the high-voltage relays is used to control the on / off state of the high-voltage circuit between the motor controller and the lithium-ion battery. High-voltage relay 2 is used to control the on / off state of the high-voltage circuit between the motor controller and the supercapacitor battery.

6. A battery control method for a range-extended electric vehicle according to any one of claims 2 to 5, characterized in that: The lithium-ion battery parameters include the lithium-ion battery temperature and the remaining capacity of the lithium-ion battery.

7. A battery control method for a range-extended electric vehicle according to any one of claims 2 to 3, characterized in that: The estimated driving power T is the required torque, r is the motor speed, and PF is the power of other electrical accessories, including the air conditioning system and DC-DC module, where T is the required torque T≥0.

8. A storage medium having a computer program stored thereon, characterized in that, When the program is executed by the processor, it implements the steps of the method as described in any one of claims 1 to 7.

9. A vehicle, characterized in that, It includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the program, implements the steps of the method as claimed in any one of claims 1 to 7.

Images