A method and system for suppressing back electromotive force of permanent magnet synchronous motor of electric vehicle

Abstract

The invention discloses a method and system for suppressing the counter electromotive force of a permanent magnet synchronous motor of an electric vehicle, and relates to the technical field of electric vehicles. If the speed is greater than the preset speed, the excitation current and torque current will be adjusted according to the voltage of the bus capacitor, and the on-off of the switching device in the three-phase bridge circuit will be controlled, so that the voltage of the bus capacitor is within the preset voltage range until the motor’s current The rotation speed is not greater than the preset rotation speed. The method and system for suppressing the back electromotive force of the permanent magnet synchronous motor of the electric vehicle in the present invention protect the bus capacitor and the switching devices in the three-phase bridge circuit from being damaged, so that the whole vehicle has enough time to use the braking system to reduce the vehicle speed Down to zero without reducing motor efficiency, overheating the motor, or increasing maintenance costs.

Description

technical field [0001] The invention relates to the technical field of electric vehicles, in particular to a method and system for suppressing back electromotive force of a permanent magnet synchronous motor of an electric vehicle. Background technique [0002] With the development of society, electric vehicles, as new energy vehicles, conform to the development trend of energy saving and environmental protection. Permanent magnet synchronous motors have become the primary choice for electric vehicle drive motors due to their high power / torque density and high efficiency. However, permanent magnet synchronous motors are excited by permanent magnets. When the vehicle is driving at high speed and the power is abnormally cut off or the high-speed faulty trailer needs to be maintained, the back electromotive force generated on the motor windings will be generated. Since the back electromotive force is proportional to the motor speed, when the back electromotive force is greater...

AI Technical Summary

Problems solved by technology

[0008] The embodiment of the present invention provides a method and system for suppressing the back EMF of a permanent magnet synchronous motor of an electric vehicle to solve the problem of reducing the efficiency of the motor, causing the motor to overheat or increasing the maintenance cost in the existing method and system for suppressing the back EMF of the permanent magnet synchronous motor of the electric vehicle technical problem

Images