Locked-rotor protection method for driving motor of electric vehicle

Abstract

The invention provides a locked-rotor protection method for a driving motor of an electric vehicle, which covers the full output range of a control torque of the driving motor. The method comprises the following steps of: dividing the control torque of the driving motor into N regions from 0 to the largest control torque according to a rotating speed signal of the driving motor and a control torque signal of a whole vehicle controller to the driving motor; setting a locked-rotor judging condition for each region and judging whether the driving motor enters into a locked-rotor state or not; if so, intervening the control torque of the driving motor by the whole vehicle controller, wherein an intervening quitting condition of the whole vehicle controller is that a rotating speed of the driving motor is more than a set rotating speed threshold value of a motor locked-rotor state. The locked-rotor protection method covers the condition that the locked-rotor may happen in the full output range of the control torque of the driving motor so as to ensure the driving motor not to be damaged by locked rotor.

Description

technical field [0001] The invention relates to the technical field of motor control of electric vehicles, and specifically designs a method for protecting a drive motor of an electric vehicle from stalling. Background technique [0002] In the actual use of traditional internal combustion engine vehicles, the phenomenon of engine flameout often occurs, mainly because the handbrake is not released in time when starting, the clutch is not stepped on in time when braking, and the brake is loosened too early when starting on a slope. Electric vehicles will also have the phenomenon that the driving motor is suffocated under the above circumstances, which is generally called motor stalling. In the national standard GB / T 18488.2-2006, the experimental method of motor stall is described in detail. When the motor is locked, the power factor is low, the locked rotor current rises rapidly, and the temperature of the inverter also rises rapidly. If it takes a long time, the driving m...

AI Technical Summary

Problems solved by technology

[0003] According to the definition of stalling in the national standard, it can be known that the stalling torque is generally the peak torque of the motor, but in the use of electric vehicles, the torque that causes the driving motor to stall is not only the peak torque, but at any point within its torque output range may cause the drive motor to stall

At the same time, when used at different ambient temperatures, the temperature rise characteristics of the drive motor when it is locked are very different.

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