Regenerative Braking Torque Curve Control Under Battery Charge Limits
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Solution Overview
Problem
Conventional energy recovery systems in electric vehicles experience uncomfortable torque step changes when battery charging power decreases, leading to sudden acceleration changes and an unpleasant driving experience.
Innovation Solution
A method and system that adjust the energy-recovery-torque curve by determining an inflection-point vehicle speed and reduction proportion based on available charging power, reducing the torque curve to match battery capacity, thereby controlling the driving electric motor for smoother energy recovery.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the originally calibrated energy-recovery-torque curve is restricted by the available power of the battery to prevent overcharge, then battery overcharge is prevented, but the smooth energy-recovery-torque curve cannot be normally responded, causing torque step changing and uncomfortable driving experience
Solution Approach 1:
The patent applies dynamics by making the energy-recovery-torque curve adjustable rather than fixed. The control system dynamically switches between a first energy-recovery-torque curve (for normal conditions) and a second energy-recovery-torque curve (for low available power conditions), allowing the system to adapt its torque characteristics based on real-time battery state and power availability, thereby preventing torque step changes and maintaining driving comfort while ensuring battery protection
Solution Approach 2:
The patent changes the torque curve parameters by introducing a second energy-recovery-torque curve with different characteristics compared to the first curve. When battery available power is low, the system switches to the second curve that is specifically designed to work within the constrained power range, avoiding the torque step changes that would occur if the first curve were simply restricted, thus maintaining smooth torque delivery while preventing battery overcharge
2Productivity
If the energy-recovery torque is maximized to recover more energy and improve driving range, then energy recovery efficiency is improved, but when battery available power decreases, torque step changing happens causing sudden acceleration changes and uncomfortable driving experience
Solution Approach 1:
The system dynamically adjusts the energy-recovery-torque curve based on real-time battery conditions. When battery available power is sufficient, the system uses the first energy-recovery-torque curve that maximizes energy recovery efficiency. When battery available power decreases below a threshold, the system automatically switches to the second energy-recovery-torque curve that operates within the reduced power range, preventing torque step changes and maintaining driving comfort while still achieving effective energy recovery
Solution Approach 2:
The patent prepares two different energy-recovery-torque curves in advance - the first curve for normal operation and the second curve for low available power conditions. By having the second curve pre-calculated and ready, the system can immediately switch to it when battery power becomes insufficient, avoiding any torque discontinuities or step changes that would compromise driving comfort, thus preliminarily preparing the appropriate torque characteristics for different operating conditions
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach alleviates or eliminates torque step changes, enhancing driving comfort by ensuring energy recovery occurs at a lower torque intensity when battery power is insufficient, maintaining smooth acceleration.
Implementation Method 1
energy recovery refers to a technique that converts part of the kinetic energy of an electric vehicle into electric energy through magnetoelectric conversion during braking or deceleration
Data Source
AI summary
The present disclosure relates to the field of vehicle technology and provides an energy recovery control method, a system, and a vehicle. The method is applied in a vehicle, and the vehicle comprises a drive motor and a battery electrically connected to the drive motor; a first energy recovery torque curve with respect to the drive motor is pre-configured in the vehicle, and the first energy recovery torque curve is used to indicate a correspondence relationship between vehicle speed and energy recovery torque of the drive motor. The present disclosure performs reduction on a first energy recovery torque curve by means of utilizing a reduction ratio, allowing energy recovery in accordance with a relatively low torque strength when a usable charge power of the battery is unable to satisfy a preset power requirement corresponding to the first energy recovery torque curve.