A control method for electric vehicle energy recovery braking parking

Abstract

The present invention relates to a control method for energy recovery brake parking of an electric vehicle, comprising the following steps: 1. When the electric vehicle is in the state of electric vehicle energy recovery brake parking, a vehicle controller collects vehicle accelerator and brake pedal signals , and analyze and generate the corresponding internal torque command. II. Adjust the above-mentioned internal torque command generated in step I through the energy recovery attenuation coefficient y. Ⅲ. The above-mentioned internal torque command adjusted in step Ⅱ is processed by de-torque processing to generate a motor torque command. IV. The above-mentioned motor torque command in step III is sent to the motor controller through CAN communication, and the motor controller controls the motor to perform corresponding torque output. The present invention adjusts the internal torque command by increasing the energy recovery attenuation coefficient y at the time before the torque command withdrawal process, so that the adjusted internal torque command curve can approach the curve of the motor torque command, and the torque command can be withdrawn more quickly .

Description

technical field [0001] The invention relates to the field of electric vehicle motor braking, in particular to a control method for electric vehicle energy recovery braking and parking. Background technique [0002] During the braking energy recovery process of a pure electric bus, the vehicle controller analyzes the driver's braking intention, and sends the corresponding electric braking torque command to the motor controller through CAN communication, and the motor controller executes the corresponding torque output. In the process of the vehicle from braking to stopping, there must be a process of removing the electric braking torque to prevent the motor from still outputting negative torque when the vehicle stops, causing the vehicle to generate driving force in the opposite direction. [0003] The traditional pure electric bus braking torque control mainly adopts a fixed energy recovery attenuation curve, mainly that is, the energy recovery attenuation start speed, energ...

AI Technical Summary

Problems solved by technology

This control method has two disadvantages: 1. If the vehicle is equipped with a high-torque motor, the vehicle needs to start untwisting at a higher speed; if the vehicle is equipped with a small-torque motor, the vehicle can start to untwist at a lower speed

However, if the initial vehicle speed of energy recovery attenuation is set too high, the low-speed energy recovery capability of the low-speed motor cannot be fully utilized; if the initial vehicle speed of energy recovery attenuation is set too low, the high-torque motor may not be able to full withdrawal

2. If the untwisting trend of the energy recovery attenuation curve is slow, the motor may not be able to fully untwist when the vehicle brakes in an emergency; Ride comfort and energy recovery performance

The starting speed of the energy recovery attenuation is set too high. Although it can ensure that the motor has no residual torque when the brake is stopped, the vehicle cannot fully utilize the motor capacity below 20 km / h due to the premature attenuation of the torque, which is not conducive to driving performance. consumption reduction

Moreover, this method does not consider the untwist time that motors with different peak torques can achieve, and uniformly sets the starting speed of energy recovery attenuation, which cannot make full use of the energy recovery capabilities of motors with different torques.

Images