Motor starting control method and system for vehicle

Abstract

The invention provides a motor starting control method and system of a vehicle. The method comprises the following steps: detecting whether an under-voltage fault occurs in a vehicle; if so, determining whether the battery voltage of the vehicle is normal after preset time; if so, acquiring a current rotating speed of a motor and a target rotating speed, corresponding to a current vehicle speed, of the motor, and controlling the current rotating speed of the motor by means of rotating-speed closed-loop control; determining whether current rotating speed of the motor reaches the target speed; and if so, controlling an output torque of the motor according to a torque command sent by the vehicle. With the method provided by the invention, a phenomenon of emergency stopping caused by zero-speed starting of the motor during the under-voltage protection is avoided; and thus the stability of the system and the comfort level of vehicle driving are improved.

Description

technical field [0001] The present invention relates to the technical field of vehicles, in particular to a motor start control method and system for a vehicle. Background technique [0002] In a moving vehicle, there is a phenomenon of busbar undervoltage caused by a short-term steep drop in battery voltage. Under the condition of undervoltage, the operating current of the motor will increase a lot, and the temperature of the motor will also increase a lot, which may cause the motor to burn out. In order to protect the motor, the vehicle generally adopts a motor undervoltage protection processing mechanism. That is, when the vehicle is running, if the battery loses power for a short time and the bus voltage drops to the motor undervoltage protection point, the motor controller detects the undervoltage and shuts off the output, reports a fault, restarts after the voltage is normal, and the vehicle controller continues Given a torque command, the motor controller must contin...

AI Technical Summary

Problems solved by technology

[0003] For example, when the driving vehicle encounters a battery power failure situation, the busbar has a short-term undervoltage at this time, the motor controller turns off the IGBT output, reports the fault, and after the voltage recovers, the motor controller normally receives the torque command sent by the vehicle controller. Control the motor to start at zero speed, but the actual vehicle speed is relatively fast. There is a speed difference between the actual speed of the motor and the output frequency of the motor controller, which causes negative torque. The actual output torque of the motor is negative, and the motor is under braking, so the vehicle will brake feeling, reducing the passenger comfort

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