Vector type permanent magnetic brushless motor control method

Abstract

The invention discloses a vector type permanent magnetic brushless motor control method. When a motor starts, by use of a constant-torque zone current closed-loop control method, a permanent magnetic brushless motor is controlled, when a PWM duty ratio output by an electric current loop proportional integral controller reaches a set threshold, by use of a constant-power weak-magnetic zone torque closed-loop control method, the permanent magnetic brushless motor is controlled; and in the constant-power weak-magnetic zone torque closed-loop control method, when a weak-magnetic control advanced conduction overlap angle delta theta FW output by a torque ring proportional integral controller is lower than a set threshold, by use of a constant-torque zone current closed-loop control method, the permanent magnetic brushless motor is controlled.

Description

technical field [0001] The invention relates to a motor control method, in particular to a vector permanent magnet brushless motor control method. Background technique [0002] Pure electric vehicles and hybrid vehicles will become the main forms of future vehicles due to their low pollution and emissions and high fuel economy. The power of pure electric vehicles and hybrid vehicles mainly uses permanent magnet synchronous motors and permanent magnet brushless motors. The permanent magnet brushless motors are permanent magnet synchronous motors with trapezoidal wave back EMF, also known as DC brushless motors. [0003] At present, the use of permanent magnet brushless motors as automotive power motors uses a six-step control strategy based on Hall sensors. Using the six-step control strategy can only achieve scalar control of the motor current. If the permanent magnet brushless motor is an embedded rotor permanent magnet, its dq axis inductance is not equal, and the maximum...

AI Technical Summary

Problems solved by technology

Using the six-step control strategy can only achieve scalar control of the motor current. If the permanent magnet brushless motor is an embedded rotor permanent magnet, its dq axis inductance is not equal, and the maximum torque output of the motor cannot be achieved using scalar control.

In addition, as the motor speed increases, the back EMF of the rotor permanent magnet gradually increases, and the scalar control based on the Hall sensor cannot realize the field weakening function, and the speed-up capability of the motor is limited

Torque output is also limited in the high rev range

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