Active thermal management method and system for improving energy recovery rate during braking

Abstract

The invention provides an active thermal management method and system for improving the energy recovery rate during braking, and relates to the field of new energy automobiles. Working parameters and environment parameters of an automobile battery and a motor are collected in real time; regulating and controlling the proportion of regenerative braking and mechanical braking according to the dynamic regulation braking strategy, and optimizing the braking recovery effect according to the braking energy recovery strategy; in the braking process, the temperature of the battery is predicted according to data collected in real time, and the battery is cooled and heated or related activities are started / stopped by adopting an automatic control strategy; and energy storage in the braking state is comprehensively adjusted. The energy utilization rate and the endurance mileage of the whole vehicle are improved, the abrasion and the failure rate of a braking system are reduced, the service life of the braking system is prolonged, the energy storage battery is protected against overheating damage, the safety of the energy storage battery is improved, the service life of the energy storage battery is prolonged, and the driving comfort and the control stability of the vehicle are improved.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular to an active thermal management method and system for improving energy recovery rate during braking. Background Art

[0002] During the braking process, a large amount of kinetic energy is converted into heat through friction and dissipated into the air. This energy waste is particularly significant in electric and hybrid vehicles. According to research, under typical urban conditions, the energy consumed by friction braking during vehicle braking accounts for about 50% of the total driving energy of the vehicle.

[0003] The braking energy recovery system can convert part of the kinetic energy into electrical energy when the vehicle brakes and store it for subsequent use. This energy recovery method is of great significance for improving the energy utilization efficiency of electric and hybrid vehicles and extending the driving range.

[0004] With the continuous development of battery technology, the performance indicators of batteries such as energy density, cycle life and safety are constantly improving, which provides better basic conditions for the application of brake energy recovery system.

[0005] With the continuous innovation of thermal management technology, many advanced thermal management methods and technical means have emerged, such as liquid cooling, heat pipe cooling, phase change material cooling, etc. The application of these technologies can more effectively control the temperature of batteries, motors and braking systems and improve energy recovery efficiency. Summary of the invention

[0006] The purpose of the present invention is to provide an active thermal management method and system for improving energy recovery rate during braking, thereby improving the energy utilization rate and cruising range of the entire vehicle, reducing the wear and failure rate of the braking system, extending its service life, protecting energy storage batteries from overheating damage, improving their safety and service life, and improving the driving comfort and handling stability of the vehicle.

[0007] To achieve the above object, the present invention provides an active thermal management method for improving energy recovery rate during braking, comprising the following steps: Real-time collection of vehicle battery, motor operating parameters and environmental parameters; The ratio of regenerative braking and mechanical braking is regulated according to the dynamic adjustment braking strategy, and the braking recovery effect is optimized according to the braking energy recovery strategy; During braking, the battery temperature is predicted based on the data collected in real time, and the battery is cooled or heated, or the related activities are started / stopped using an automatic control strategy; A comprehensive adjustment of energy storage under braking state is provided.

[0008] Preferably, the power, voltage, current and charge state of the vehicle battery, the torque and speed of the motor, the operating power of the condenser and the evaporator, and the environmental parameters include the ambient temperature.

[0009] Preferably, the ratio of regenerative braking and mechanical braking is regulated according to the dynamic adjustment braking strategy, including The fuzzy logic control strategy is adopted to automatically adjust the ratio of mechanical braking force to regenerative braking force according to different braking intensities. Among them, different braking intensities are roughly divided into four categories: active emergency braking, passive emergency braking, active gentle braking state and passive gentle braking state, including Set input variables and output variables, where the input variables are braking intensity, battery state of charge and vehicle speed; the output variable is the ratio of regenerative braking force to mechanical braking force; Set fuzzy rules to describe the mapping relationship between input variables and output variables: Active emergency braking: In active emergency braking, the ratio of mechanical braking force to regenerative braking force is usually 70% mechanical braking force and 30% regenerative braking force. This ratio ensures rapid deceleration while recovering as much energy as possible. Passive emergency braking: In passive emergency braking, the ratio of mechanical braking force to regenerative braking force may be closer to 50% mechanical braking force and 50% regenerative braking force, because the system mainly relies on the driver's response. In this case, the energy recovery efficiency may be slightly lower than that of active emergency braking. Active gentle braking: In the active gentle braking state, in order to improve the energy recovery efficiency, the ratio of mechanical braking force to regenerative braking force can be adjusted to 30% mechanical braking force and 70% regenerative braking force. This ratio is suitable for when the vehicle is slowly decelerating or driving downhill; Passive gentle braking: In passive gentle braking, due to the lower braking intensity, the ratio of mechanical braking force to regenerative braking force can also be set to a lower mechanical braking force, such as 40% mechanical braking force and 60% regenerative braking force, which helps to maximize energy recovery while ensuring braking effect; The collected working parameters of the car battery and motor are converted into membership values ​​in the fuzzy set, including (1) Braking strength ; (2) Battery state of charge Battery charge status soc = ; (3) Vehicle speed Speed v = ; According to the rules and membership values ​​in the fuzzy rule base, fuzzy reasoning is performed to obtain the fuzzy value of the output variable; The maximum membership method is used to convert the fuzzy value of the output variable obtained by fuzzy reasoning into the specific ratio of the regenerative braking force to the mechanical braking force.

[0010] Preferably, during the braking process, the battery temperature is predicted based on the data collected in real time, the battery is cooled or heated, or the automatic control strategy is used to start / stop related activities, and the automatic adjustment strategy is adjusted according to the ambient temperature, battery power, battery load status, and motor speed, specifically: Establish the first temperature control model, and determine whether heating or cooling is needed based on the temperature control model. When the output value of the first temperature control model is greater than the threshold range, the condensing device is started to cool the system; When the output value of the first temperature control model is less than the threshold range, the evaporation device is started to heat up the system; When the output value of the first temperature control model is within the set threshold range, the temperature is neither lowered nor raised.

[0011] Preferably, the first temperature control model is Q total = P loss + P other ; in, Q total is the total heat of the system; P loss is the heat lost; P othe rThe cooling capacity required by other cooling units.

[0012] Preferably, temperature sensors are also provided at the battery, motor and environment. When the temperature transmitted by any temperature sensor exceeds the corresponding set value, the required cooling capacity is calculated according to the constructed second temperature control model, and the corresponding cooling unit is cooled.

[0013] Preferably, a comprehensive adjustment of energy storage under braking state is provided, including two situations: According to the energy storage strategy, when the battery load state is higher than the set threshold or the battery temperature is higher than the limit value, the kinetic energy generated by the torque of the motor is stopped from being converted into electrical energy and stored in the battery; During low-intensity braking, electric motor braking is used for energy recovery first; during high-intensity braking, mechanical braking is combined to ensure driving safety, and the priority of energy recovery is appropriately reduced to avoid overheating.

[0014] An active thermal management system for improving energy recovery during braking, including The acquisition module is used to collect the working parameters of the car battery and motor and the environmental parameters in real time; The energy recovery module is used to adjust the ratio of regenerative braking and mechanical braking according to the dynamic adjustment braking strategy, and optimize the braking recovery effect according to the braking energy recovery strategy; The active thermal management module is used to predict the battery temperature based on the real-time collected data during braking, cool or heat the battery, or start / stop related activities using automatic control strategies; The comprehensive control module is used to set up comprehensive adjustment of energy storage under braking state.

[0015] An electronic device comprises a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the processor implements the steps of an active thermal management method for improving energy recovery rate during braking.

[0016] A storage medium stores computer executable instructions, which, when loaded and executed by a processor, implement the steps of an active thermal management method for improving energy recovery rate during braking.

[0017] Therefore, the present invention adopts the above-mentioned active thermal management method and system for improving energy recovery rate during braking, and the technical effects are as follows: 1. Improve energy recovery efficiency Optimizing energy flow: Active thermal management methods monitor the temperature of the battery, motor and brake system in real time and adjust the cooling or heating strategy to ensure that these components operate within the optimal temperature range. This helps reduce energy loss caused by high or low temperatures, thereby improving the efficiency of braking energy recovery.

[0018] Reduce thermal decay: At high temperatures, the friction material of the brake system is prone to thermal decay, resulting in reduced braking performance. Active thermal management can effectively alleviate the thermal decay phenomenon by timely cooling, maintaining the stability and reliability of the brake system, thereby further improving the efficiency of energy recovery.

[0019] 2. Extend component life Protecting batteries: The battery is one of the core components of electric and hybrid vehicles, and its life directly affects the overall performance and economy of the vehicle. Active thermal management controls the battery temperature to prevent the battery from overheating or overcooling, thereby extending the battery life.

[0020] Reduce wear: The combination of mechanical braking system and regenerative braking system will produce certain wear during the braking process. Active thermal management reduces the frequency and intensity of use of the mechanical braking system by optimizing the braking strategy, thereby reducing wear and extending the service life of the braking system.

[0021] 3. Improved security Prevent thermal runaway: Batteries are prone to thermal runaway at extreme temperatures, leading to safety accidents such as fire or explosion. Active thermal management monitors battery temperature in real time and takes timely cooling measures to prevent thermal runaway and improve vehicle safety.

[0022] Stable braking performance: During braking, stable braking performance is one of the key factors to ensure driving safety. Active thermal management optimizes braking strategies to ensure that the braking system can provide stable braking force under different working conditions, thereby improving driving safety.

[0023] 4. Optimize driving experience Reduced noise and vibration: High temperatures can cause mechanical parts to expand and deform, increasing noise and vibration. Active thermal management reduces the expansion and deformation of mechanical parts by controlling temperature, thereby reducing noise and vibration and improving the driving experience.

[0024] Improve response speed: Electric brakes respond quickly, while mechanical brakes respond slowly. Active thermal management optimizes the braking strategy so that electric brakes and mechanical brakes can better coordinate and cooperate, improve the response speed of the braking system, and make driving smoother.

[0025] 5. Environmental protection and energy saving Reduced energy waste: By increasing the rate of brake energy recovery, active thermal management methods can significantly reduce energy waste and reduce the vehicle's dependence on fossil fuels.

[0026] Lower emissions: Energy recovered during braking in electric and hybrid vehicles can reduce reliance on the grid, thereby reducing carbon emissions and other pollutants from power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 A flow chart of an active thermal management method for improving energy recovery rate during braking according to the present invention; Figure 2 The schematic diagram of an active thermal management system for improving energy recovery rate during braking according to the present invention. DETAILED DESCRIPTION

[0028] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0029] Unless otherwise defined, technical or scientific terms used in the present invention shall have the common meanings understood by one having ordinary skills in the field to which the present invention belongs.

[0030] Embodiment 1 like Figure 1 As shown, the present invention provides an active thermal management method for improving energy recovery rate during braking, comprising the following steps: Step 1: Collect the working parameters and environmental parameters of the car battery and motor in real time; The power, voltage, current and state of charge of the car battery, the torque and speed of the motor, the operating power of the condenser and evaporator, and environmental parameters including ambient temperature.

[0031] Step 2: dynamically adjust the braking strategy to adjust the ratio of regenerative braking and mechanical braking, and optimize the braking recovery effect according to the braking energy recovery strategy, including The fuzzy logic control strategy is adopted to automatically adjust the ratio of mechanical braking force to regenerative braking force according to different braking intensities. Among them, different braking intensities are roughly divided into four categories: active emergency braking, passive emergency braking, active gentle braking state and passive gentle braking state, including Set input variables and output variables, where the input variables are braking intensity, battery state of charge and vehicle speed; the output variable is the ratio of regenerative braking force to mechanical braking force; Set fuzzy rules to describe the mapping relationship between input variables and output variables: Active emergency braking: In active emergency braking, the ratio of mechanical braking force to regenerative braking force is usually 70% mechanical braking force and 30% regenerative braking force. This ratio ensures rapid deceleration while recovering as much energy as possible. Passive emergency braking: In passive emergency braking, the ratio of mechanical braking force to regenerative braking force may be closer to 50% mechanical braking force and 50% regenerative braking force, because the system mainly relies on the driver's response. In this case, the energy recovery efficiency may be slightly lower than that of active emergency braking. Active gentle braking: In the active gentle braking state, in order to improve the energy recovery efficiency, the ratio of mechanical braking force to regenerative braking force can be adjusted to 30% mechanical braking force and 70% regenerative braking force. This ratio is suitable for when the vehicle is slowly decelerating or driving downhill; Passive gentle braking: In passive gentle braking, due to the lower braking intensity, the ratio of mechanical braking force to regenerative braking force can also be set to a lower mechanical braking force, such as 40% mechanical braking force and 60% regenerative braking force, which helps to maximize energy recovery while ensuring braking effect; The collected working parameters of the car battery and motor are converted into membership values ​​in the fuzzy set, including (1) Braking strength ; (2) Battery state of charge Battery charge status soc = ; (3) Vehicle speed Speed v = ; According to the rules and membership values ​​in the fuzzy rule base, fuzzy reasoning is performed to obtain the fuzzy value of the output variable; The maximum membership method is used to convert the fuzzy value of the output variable obtained by fuzzy reasoning into the specific ratio of the regenerative braking force to the mechanical braking force.

[0032] Step 3: During the braking process, the temperature of the battery is predicted based on the data collected in real time, and the battery is cooled or heated, or related activities are started / stopped using an automatic control strategy; The automatic adjustment strategy is adjusted according to the ambient temperature, battery power, battery load status, and motor speed. This active control can more accurately adjust the thermal management strategy according to the actual operating conditions of the vehicle, thereby improving the efficiency and effectiveness of thermal management. Specifically: Establish the first temperature control model, and determine whether heating or cooling is needed based on the temperature control model. When the output value of the first temperature control model is greater than the threshold range, the condensing device is started to cool the system; When the output value of the first temperature control model is less than the threshold range, the evaporation device is started to heat up the system; When the output value of the first temperature control model is within the set threshold range, the temperature is neither lowered nor raised.

[0033] The first temperature control model is Q total = P loss + P other ; in, Q total is the total heat of the system; P loss is the heat lost; P othe rThe cooling capacity required by other cooling units.

[0034] In addition, temperature sensors are installed at the battery, motor and environment. When the temperature transmitted by any temperature sensor exceeds the corresponding set value, the required cooling capacity is calculated according to the constructed second temperature control model, and the corresponding cooling unit is cooled. This can not only extend the service life of the battery and motor, but also improve the energy efficiency and performance of the whole vehicle.

[0035] Step 4: Set up comprehensive adjustment of energy storage under braking state There is a comprehensive adjustment of the energy storage under braking state, including two situations: According to the energy storage strategy, when the battery load state is higher than the set threshold or the battery temperature is higher than the limit value, the kinetic energy generated by the torque of the motor is stopped from being converted into electrical energy and stored in the battery; During low-intensity braking, electric motor braking is used for energy recovery first; during high-intensity braking, mechanical braking is combined to ensure driving safety, and the priority of energy recovery is appropriately reduced to avoid overheating.

[0036] In summary, the change in the torque of the motor during braking involves the motor's transition from a driving state to a power generation state. Energy recovery is achieved by controlling the torque of the motor. This process not only helps to improve energy utilization efficiency, but also helps to improve the endurance of electric vehicles.

[0037] like Figure 2 As shown, an active thermal management system for improving energy recovery during braking includes The acquisition module is used to collect the working parameters of the car battery and motor and the environmental parameters in real time; The energy recovery module is used to adjust the ratio of regenerative braking and mechanical braking according to the dynamic adjustment braking strategy, and optimize the braking recovery effect according to the braking energy recovery strategy; The active thermal management module is used to predict the battery temperature based on the real-time collected data during braking, cool or heat the battery, or start / stop related activities using automatic control strategies; The comprehensive control module is used to set up comprehensive adjustment of energy storage under braking state.

[0038] Since the embodiments of the apparatus part correspond to the embodiments of the method part, please refer to the description of the embodiments of the method part for the embodiments of the apparatus part, which will not be repeated here.

[0039] The present application also provides a storage medium on which a computer program is stored, and when the computer program is executed, the steps provided in the above embodiment can be implemented. The storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0040] The present application also provides an electronic device, which may include a memory and a processor, wherein a computer program is stored in the memory, and when the processor calls the computer program in the memory, the steps provided in the above embodiment may be implemented. Of course, the electronic device may also include various network interfaces, power supplies and other components.

[0041] Therefore, the present invention adopts the above-mentioned active thermal management method and system for improving the energy recovery rate during braking, thereby improving the energy utilization rate and cruising range of the entire vehicle, reducing the wear and failure rate of the braking system, extending its service life, protecting the energy storage battery from overheating damage, improving its safety and service life, and improving the driving comfort and handling stability of the vehicle.

[0042] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. An active thermal management method for improving energy recovery during braking, characterized in that: The following steps are involved: Real-time collection of vehicle battery, motor operating parameters and environmental parameters; The ratio of regenerative braking and mechanical braking is regulated according to the dynamic adjustment braking strategy, and the braking recovery effect is optimized according to the braking energy recovery strategy; During braking, the battery temperature is predicted based on the data collected in real time, and the battery is cooled or heated, or the related activities are started / stopped using an automatic control strategy; A comprehensive adjustment of energy storage under braking state is provided.

2. The active thermal management method for improving energy recovery rate during braking according to claim 1, characterized in that: The power, voltage, current and state of charge of the car battery, the torque and speed of the motor, the operating power of the condenser and evaporator, and environmental parameters including ambient temperature.

3. The active thermal management method for improving energy recovery rate during braking according to claim 1, characterized in that: Dynamically adjust the braking strategy to adjust the ratio of regenerative braking and mechanical braking, including The fuzzy logic control strategy is adopted to automatically adjust the ratio of mechanical braking force to regenerative braking force according to different braking intensities. Among them, different braking intensities are roughly divided into four categories: active emergency braking, passive emergency braking, active gentle braking state and passive gentle braking state, including Set input variables and output variables, where the input variables are braking intensity, battery state of charge and vehicle speed; the output variable is the ratio of regenerative braking force to mechanical braking force; Set fuzzy rules to describe the mapping relationship between input variables and output variables; Convert the collected working parameters of the car battery and motor into membership values ​​in the fuzzy set; According to the rules and membership values ​​in the fuzzy rule base, fuzzy reasoning is performed to obtain the fuzzy value of the output variable; The maximum membership method is used to convert the fuzzy value of the output variable obtained by fuzzy reasoning into the specific ratio of the regenerative braking force to the mechanical braking force.

4. The active thermal management method for improving energy recovery rate during braking according to claim 3, characterized in that: Set fuzzy rules to describe the mapping relationship between input variables and output variables: Active emergency braking: In active emergency braking, the ratio of mechanical braking force to regenerative braking force is usually 70% mechanical braking force and 30% regenerative braking force. This ratio ensures rapid deceleration while recovering as much energy as possible. Passive emergency braking: In passive emergency braking, the ratio of mechanical braking force to regenerative braking force may be closer to 50% mechanical braking force and 50% regenerative braking force, because the system mainly relies on the driver's response. In this case, the energy recovery efficiency may be slightly lower than that of active emergency braking. Active gentle braking: In the active gentle braking state, in order to improve the energy recovery efficiency, the ratio of mechanical braking force to regenerative braking force can be adjusted to 30% mechanical braking force and 70% regenerative braking force. This ratio is suitable for when the vehicle is slowly decelerating or driving downhill; Passive gentle braking: In the passive gentle braking state, due to the lower braking intensity, the ratio of mechanical braking force to regenerative braking force can also be set to a lower mechanical braking force, such as 40% mechanical braking force and 60% regenerative braking force, which helps to maximize energy recovery while ensuring braking effect.

5. The active thermal management method for improving energy recovery rate during braking according to claim 3, characterized in that: The collected working parameters of the car battery and motor are converted into membership values ​​in the fuzzy set, including (1) Braking strength ； (2) Battery state of charge ； (3) Vehicle speed 。 6. The active thermal management method for improving energy recovery rate during braking according to claim 1, characterized in that: During the braking process, the battery temperature is predicted based on the real-time collected data, and the battery is cooled, heated, or the automatic control strategy is used to start / stop related activities. The automatic adjustment strategy is adjusted according to the ambient temperature, battery power, battery load status, and motor speed. Specifically: Establish the first temperature control model, and determine whether heating or cooling is needed based on the temperature control model. When the output value of the first temperature control model is greater than the threshold range, the condensing device is started to cool the system; When the output value of the first temperature control model is less than the threshold range, the evaporation device is started to heat up the system; When the output value of the first temperature control model is within the set threshold range, the temperature is neither lowered nor raised.

7. The active thermal management method for improving energy recovery rate during braking according to claim 4, characterized in that: The first temperature control model is Q total = P loss + P other ； in, Q total is the total heat of the system; P loss is the heat lost; P othe rThe cooling capacity required by other cooling units.

8. The active thermal management method for improving energy recovery rate during braking according to claim 4, characterized in that: Temperature sensors are provided at the battery, motor and environment. When the temperature transmitted by any temperature sensor exceeds the corresponding set value, the required cooling capacity is calculated according to the constructed second temperature control model, and the corresponding cooling unit is cooled.

9. The active thermal management method for improving energy recovery rate during braking according to claim 1, characterized in that: There is a comprehensive adjustment of the energy storage under braking state, including two situations: According to the energy storage strategy, when the battery load state is higher than the set threshold or the battery temperature is higher than the limit value, the kinetic energy generated by the torque of the motor is stopped from being converted into electrical energy and stored in the battery; During low-intensity braking, motor braking is used first for energy recovery; During high-intensity braking, mechanical braking is combined to ensure driving safety, and energy recovery priority is appropriately reduced to avoid overheating.

10. An active thermal management system for improving energy recovery during braking, characterized in that: include The acquisition module is used to collect the working parameters of the car battery and motor and the environmental parameters in real time; The energy recovery module is used to adjust the ratio of regenerative braking and mechanical braking according to the dynamic adjustment braking strategy, and optimize the braking recovery effect according to the braking energy recovery strategy; The active thermal management module is used to predict the battery temperature based on the real-time collected data during braking, cool or heat the battery, or start / stop related activities using automatic control strategies; The comprehensive control module is used to set up comprehensive adjustment of energy storage under braking state.

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