Control device and control method for self-adaptive fuzzy control of peak working condition of power battery
By designing a control device that automatically adjusts the driving output power in electric vehicles, the problem of vehicle speed fluctuations under peak operating conditions is solved, and the driving experience without increasing hardware costs is improved and market competitiveness is enhanced.
Patent Information
- Application Number
- CN202411788366.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-06
- Publication Date
- 2025-01-10
AI Technical Summary
The high-power pulse discharge of the power battery of electric vehicles under peak operating conditions causes vehicle speed fluctuations, affecting driving experience and safety. The existing BMS control strategy is complex and increases hardware and calibration costs.
Design an electric vehicle driving power control device, adjust the output power in real time through the vehicle controller, and automatically switch the power limit mode according to the power battery status, vehicle speed and accelerator pedal position to reduce vehicle speed fluctuations and avoid complex control strategies and increased hardware costs.
Effectively reduce vehicle speed fluctuations and improve driving experience without increasing hardware or calibration costs, reducing vehicle costs and improving market competitiveness.
Smart Images
Figure CN119283718A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of electric vehicle power control, and in particular relates to a control device and a control method for adaptive fuzzy control of a power battery under peak operating conditions. Background Art
[0002] With the increasing global awareness of environmental protection and the continuous advancement of technology, electric vehicles (EV) have gradually become an important development direction of the automotive industry. Among them, power batteries, as one of the core components of electric vehicles, undertake the important task of providing power sources for the entire vehicle. However, in actual application, power batteries face many challenges, especially how to ensure efficient energy utilization while avoiding performance degradation or even damage caused by overcharging or over-discharging of the battery. In order to solve these problems, modern electric vehicles are usually equipped with a complex battery management system (BMS), which can monitor the status of the battery in real time and dynamically adjust the battery output power according to the actual operation of the vehicle.
[0003] During the operation of electric vehicles, especially under high load conditions such as acceleration and climbing, the battery needs to provide instantaneous high power output, which is called peak operating conditions. Under these conditions, the output power of the power battery will be strictly limited by its pulse discharge capability. In order to ensure the safety of the battery and extend its service life, the BMS will take a series of measures to control the discharge process of the battery. When the vehicle enters the peak operating condition, the BMS will first allow the battery to output at the maximum pulse power, but this state cannot be maintained for a long time, because after a certain period of time, the battery temperature will rise, the internal resistance will increase, and the battery may be damaged. Therefore, after the high-power pulse discharge is completed, the BMS will automatically switch the system to a lower power level, so that the battery has a short recovery period. This process will be repeated periodically, resulting in vehicle speed fluctuations when accelerating or climbing, affecting the driving experience.
[0004] The periodic fluctuation of vehicle speed is mainly caused by the following factors: Battery performance recovery: Every time you switch from high power to low power, the battery has a cooling and recovery process, which will cause a temporary drop in output power and thus affect vehicle speed.
[0005] BMS algorithm: The BMS control algorithm determines when to switch from high power to low power. The choice of this switching point directly affects the change in vehicle speed.
[0006] Vehicle load changes: When climbing a hill or accelerating, the vehicle's load will change continuously, which also requires the BMS to frequently adjust the power output to maintain optimal performance.
[0007] This speed fluctuation not only affects the driver's comfort, but may also affect the safety of the vehicle to a certain extent. For example, in emergency avoidance or high-speed driving, sudden changes in vehicle speed may increase the risk of accidents.
[0008] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention and should not be regarded as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art. Summary of the invention
[0009] The object of the present invention is to provide a control device and a control method for adaptive fuzzy control of a power battery under peak operating conditions, so as to overcome the problems in the prior art.
[0010] To achieve the above object, the present invention provides an electric vehicle driving power control device, comprising: The vehicle controller is used to receive and process data from the accelerator pedal displacement sensor, vehicle speed signal device, power battery controller and drive motor controller, and adjust the real-time output power of the vehicle according to these data; The accelerator pedal displacement sensor is used to detect the position change of the accelerator pedal and send the information to the vehicle controller; Vehicle speed signal device, used to monitor vehicle speed and provide real-time speed information to the vehicle controller; The power battery controller is used to monitor the status of the power battery, mainly the pulse discharge power, and transmit the relevant information to the vehicle controller; The drive motor controller is used to adjust the output power of the motor according to the instructions of the vehicle controller.
[0011] The vehicle controller further includes: The first acquisition module is used to acquire and update the minimum pulse power limit value Wb0 of the power battery under restricted working conditions; The second acquisition module is used to acquire and update the vehicle speed V0 when the vehicle is running at the lowest pulse power under the restricted working condition; The third acquisition module is used to acquire and update the driver's limited demand power Wa0 corresponding to the accelerator pedal position when the minimum pulse power is running under the restricted working condition; The first switching module is used to switch the real-time driving output power Wv in the power limiting mode.
[0012] The beneficial effects of this device are: Compared with adding ramp switches and loop solutions, this device and control method can save about 20 yuan per unit in hardware costs, can save more than tens of thousands of yuan in corresponding calibration and development costs, and avoid the performance degradation caused by the corresponding control strategy that is difficult to perfect, and can effectively reduce the user's operating burden and learning cost; Compared with adding a slope sensor and loop solution, this device and control method can save about 60 yuan per unit in hardware costs, can save more than hundreds of thousands of yuan in corresponding calibration and development costs, and avoid the corresponding more complex control strategy development work; the cost of the entire vehicle is relatively reduced, which helps to improve the product's market competitiveness.
[0013] A control method based on the above-mentioned electric vehicle driving power control device comprises the following steps: When the real-time pulse discharge power limit value Wb of the power battery is less than the real-time required power Wa of the driver, the power limit mode is entered; In the power limiting mode, when Wb≤Wb0, the limit values are updated to Wb0=Wb, V0=V, Wa0=Wa, and Wv0=Wb-△; In the power limiting mode, when V / V0>Kv, the power limiting mode is exited, and Wv=Wa; In the power limit mode, when |Wa-Wa0| / Wa0>Kw, exit the power limit mode, Wv=Wa; In the power limiting mode, when V / V0≤Kv and |Wa-Wa0| / Wa0≤Kw, Wv=Wv0.
[0014] Wb0: minimum pulse power limit of the power battery under restricted working conditions; V0: vehicle speed when operating at minimum pulse power under restricted conditions; Wa0: The accelerator pedal position corresponds to the driver's limited demand power when operating at the lowest pulse power under restricted conditions; Wv0: driving limit output power under restricted working conditions; Wb: real-time pulse discharge power limit of power battery; V: real-time vehicle speed; Wa: real-time power demanded by the driver; Wv: real-time output power during driving; △: adjustment amount; Kv: vehicle speed change ratio threshold; Kw: Driver demand power change ratio threshold.
[0015] The above-mentioned technical means can automatically adjust the real-time output power of the vehicle during driving to reduce repeated fluctuations in vehicle speed and improve the driver's driving experience without adding additional hardware or calibration costs.
[0016] Preferably, in the above technical solution, in the power limiting mode, when the real-time pulse discharge power limit Wb of the power battery is less than or equal to the minimum pulse power limit Wb0, the limit Wb0=Wb is updated, and V0=V and Wa0=Wa are updated at the same time, and the driving limit output power is set to Wv0=Wb-△, where △ is the preset adjustment amount.
[0017] Preferably, in the above technical solution, in the limited power mode, if the ratio V / V0 of the real-time vehicle speed to the vehicle speed when the minimum pulse power is running is greater than the preset vehicle speed change ratio threshold Kv, the limited power mode is exited and the real-time driving output power is set to the driver's real-time required power Wv=Wa.
[0018] Preferably, in the above technical solution, in the limited power mode, if the rate of change of the driver's real-time required power and the driver's limited required power corresponding to the accelerator pedal position when the minimum pulse power is running |Wa-Wa0| / Wa0 is greater than the preset required power change ratio threshold Kw, the limited power mode is exited and the real-time driving output power is set to the driver's real-time required power Wv=Wa.
[0019] Preferably, in the above technical scheme, in the limited power mode, if the ratio of the real-time vehicle speed to the vehicle speed when the minimum pulse power is running V / V0 is not greater than the preset vehicle speed change ratio threshold Kv and the rate of change of the driver's real-time required power and the driver's limited required power corresponding to the accelerator pedal position when the minimum pulse power is running |Wa-Wa0| / Wa0 is not greater than the preset required power change ratio threshold Kw, then the real-time driving output power is maintained at the driving limit output power Wv=Wv0 under restricted conditions.
[0020] Compared with the prior art, the present invention has the following beneficial effects: It realizes automatic adjustment of driving power without increasing hardware and calibration costs, avoids repeated fluctuations in vehicle speed under restricted conditions, and avoids giving the driver the subjective feeling that the vehicle condition is abnormal. BRIEF DESCRIPTION OF THE DRAWINGS
[0021] Attached Figure 1 is a schematic diagram of the device of the present invention; Attached Figure 2 It is a functional schematic diagram of the vehicle controller of the present invention; Attached Figure 3 It is a program schematic diagram of the control method of the present invention. DETAILED DESCRIPTION
[0022] The specific embodiments of the present invention are described in detail below, but it should be understood that the protection scope of the present invention is not limited by the specific embodiments.
[0023] Unless explicitly stated otherwise, throughout the specification and claims, the term “comprise” or variations such as “include” or “comprising”, etc., will be understood to include the stated elements or components but not to exclude other elements or components.
[0024] A driving power control device for an electric vehicle, comprising: The vehicle controller is used to receive and process data from the accelerator pedal displacement sensor, vehicle speed signal device, power battery controller and drive motor controller, and adjust the real-time output power of the vehicle according to these data; The accelerator pedal displacement sensor is used to detect the position change of the accelerator pedal and send the information to the vehicle controller; Vehicle speed signal device, used to monitor vehicle speed and provide real-time speed information to the vehicle controller; The power battery controller is used to monitor the status of the power battery, mainly the pulse discharge power, and transmit the relevant information to the vehicle controller; The drive motor controller is used to adjust the output power of the motor according to the instructions of the vehicle controller.
[0025] The vehicle controller further includes: The first acquisition module is used to acquire and update the minimum pulse power limit value Wb0 of the power battery under restricted working conditions; The second acquisition module is used to acquire and update the vehicle speed V0 when the vehicle is running at the lowest pulse power under the restricted working condition; The third acquisition module is used to acquire and update the driver's limited demand power Wa0 corresponding to the accelerator pedal position when the minimum pulse power is running under the restricted working condition; The first switching module is used to switch the real-time driving output power Wv in the power limiting mode.
[0026] In the power limit mode, when the real-time pulse discharge power limit Wb of the power battery is less than or equal to the minimum pulse power limit Wb0, the limit Wb0=Wb is updated, and V0=V and Wa0=Wa are updated at the same time, and the driving limit output power is set to Wv0=Wb-△, where △ is the preset adjustment amount.
[0027] In the power limiting mode, if the ratio V / V0 of the real-time vehicle speed to the vehicle speed when the minimum pulse power is running is greater than the preset vehicle speed change ratio threshold Kv, the power limiting mode is exited and the real-time output power of the vehicle is set to the real-time required power of the driver Wv=Wa.
[0028] In the power limiting mode, if the rate of change of the driver's real-time power demand and the driver's limited demand power corresponding to the accelerator pedal position when the minimum pulse power is running |Wa-Wa0| / Wa0 is greater than the preset demand power change ratio threshold Kw, the power limiting mode is exited and the real-time driving output power is set to the driver's real-time demand power Wv=Wa.
[0029] In the limited power mode, if the ratio of the real-time vehicle speed to the vehicle speed when the minimum pulse power is running V / V0 is not greater than the preset vehicle speed change ratio threshold Kv and the rate of change of the driver's real-time demand power and the driver's limited demand power corresponding to the accelerator pedal position when the minimum pulse power is running |Wa-Wa0| / Wa0 is not greater than the preset demand power change ratio threshold Kw, then the real-time driving output power is maintained at the driving limit output power Wv=Wv0 under restricted conditions.
[0030] A control method based on the above-mentioned electric vehicle driving power control device comprises the following steps: When the real-time pulse discharge power limit value Wb of the power battery is less than the real-time required power Wa of the driver, the power limit mode is entered; In the power limiting mode, when Wb≤Wb0, the limit values are updated to Wb0=Wb, V0=V, Wa0=Wa, and Wv0=Wb-△; In the power limiting mode, when V / V0>Kv, the power limiting mode is exited, and Wv=Wa; In the power limit mode, when |Wa-Wa0| / Wa0>Kw, exit the power limit mode, Wv=Wa; In the power limited mode, when V / V0≤Kv and |Wa-Wa0| / Wa0≤Kw, Wv=Wv0. The real-time output power is automatically adjusted through the above-mentioned technical means to reduce the repeated fluctuations in vehicle speed and improve the driver's driving experience without adding additional hardware or calibration costs.
[0031] Attached Figure 1 It is a schematic diagram of the device of the present invention, including a driving controller 100, an accelerator pedal displacement sensor 200, a vehicle speed signal device 300, a power battery controller 400, and a drive motor controller 500.
[0032] Attached Figure 2 The first acquisition module 111 acquires and updates the minimum pulse power limit value Wb0 of the power battery under restricted working conditions, the second acquisition module 112 acquires and updates the vehicle speed V0 when the minimum pulse power is running under restricted working conditions, the third acquisition module 113 acquires and updates the accelerator pedal position corresponding to the driver's limited demand power Wa0 when the minimum pulse power is running under restricted working conditions, the first switching module 121 switches the real-time output power Wv during driving, Attached Figure 3 It is a program diagram of the control method of the present invention. When Wb<Wa, it enters the power limiting mode, otherwise, Wv=Wa; In power limit mode, when Wb≤Wb0, update the limit value Wb0=Wb, V0=V, Wa0=Wa, Wv0=Wb-△; In the power limiting mode, when V / V0>Kv, the power limiting mode is exited, and Wv=Wa; In the power limit mode, when |Wa-Wa0| / Wa0>Kw, exit the power limit mode, Wv=Wa; In the power limiting mode, when V / V0≤Kv and |Wa-Wa0| / Wa0≤Kw, Wv=Wv0.
[0033] The foregoing description of specific exemplary embodiments of the present invention is for the purpose of illustration and demonstration. These descriptions are not intended to limit the present invention to the precise form disclosed, and it is clear that many changes and variations can be made based on the above teachings. The purpose of selecting and describing the exemplary embodiments is to explain the specific principles of the present invention and its practical application, so that those skilled in the art can realize and utilize various different exemplary embodiments of the present invention and various different selections and changes. The scope of the present invention is intended to be limited by the claims and their equivalents.
Claims
1. A driving power control device for an electric vehicle, characterized in that: include: The vehicle controller is used to receive and process data from the accelerator pedal displacement sensor, vehicle speed signal device, power battery controller and drive motor controller, and adjust the real-time output power of the vehicle according to these data; The accelerator pedal displacement sensor is used to detect the position change of the accelerator pedal and send the information to the vehicle controller; Vehicle speed signal device, used to monitor vehicle speed and provide real-time speed information to the vehicle controller; The power battery controller is used to monitor the status of the power battery, mainly the pulse discharge power, and transmit the relevant information to the vehicle controller; The drive motor controller is used to adjust the output power of the motor according to the instructions of the vehicle controller; The vehicle controller includes: The first acquisition module is used to acquire and update the minimum pulse power limit value Wb0 of the power battery under restricted working conditions; The second acquisition module is used to acquire and update the vehicle speed V0 when the vehicle is running at the lowest pulse power under the restricted working condition; The third acquisition module is used to acquire and update the driver's limited demand power Wa0 corresponding to the accelerator pedal position when the minimum pulse power is running under the restricted working condition; The first switching module is used to switch the real-time driving output power Wv in the power limiting mode.
2. A control method based on the electric vehicle driving power control device according to claim 1, characterized in that: The following steps are involved: When the real-time pulse discharge power limit value Wb of the power battery is less than the real-time required power Wa of the driver, the power limit mode is entered; In the power limiting mode, when Wb≤Wb0, the limit values are updated to Wb0=Wb, V0=V, Wa0=Wa, and Wv0=Wb-△; In the power limiting mode, when V / V0>Kv, the power limiting mode is exited, and Wv=Wa; In the power limit mode, when |Wa-Wa0| / Wa0>Kw, exit the power limit mode, Wv=Wa; In the power limiting mode, when V / V0≤Kv and |Wa-Wa0| / Wa0≤Kw, Wv=Wv0.
3. The control method according to claim 2, characterized in that: In the power limit mode, when the real-time pulse discharge power limit Wb of the power battery is less than or equal to the minimum pulse power limit Wb0, the limit Wb0=Wb is updated, and V0=V and Wa0=Wa are updated at the same time, and the driving limit output power is set to Wv0=Wb-△, where △ is the preset adjustment amount.
4. The control method according to claim 2 or 3, characterized in that: In the power limiting mode, if the ratio V / V0 of the real-time vehicle speed to the vehicle speed when the minimum pulse power is running is greater than the preset vehicle speed change ratio threshold Kv, the power limiting mode is exited and the real-time output power of the vehicle is set to the real-time required power of the driver Wv=Wa.
5. The control method according to claim 2 or 3, characterized in that: In the power limiting mode, if the rate of change of the driver's real-time power demand and the driver's limited demand power corresponding to the accelerator pedal position when the minimum pulse power is running |Wa-Wa0| / Wa0 is greater than the preset demand power change ratio threshold Kw, the power limiting mode is exited and the real-time driving output power is set to the driver's real-time demand power Wv=Wa.
6. The control method according to claim 2 or 3, characterized in that: In the limited power mode, if the ratio of the real-time vehicle speed to the vehicle speed when the minimum pulse power is running V / V0 is not greater than the preset vehicle speed change ratio threshold Kv and the rate of change of the driver's real-time demand power and the driver's limited demand power corresponding to the accelerator pedal position when the minimum pulse power is running |Wa-Wa0| / Wa0 is not greater than the preset demand power change ratio threshold Kw, then the real-time driving output power is maintained at the driving limit output power Wv=Wv0 under restricted conditions.