Current predictive control method of permanent magnet synchronous motor

Abstract

The invention relates to a current predictive control method of a permanent magnet synchronous motor, which belongs to the electric control field. The dynamic response speed and the control accuracy for the stator current control of the permanent magnet synchronous motor are improved through stator current prediction and deadbeat control, and the system delaying is compensated, so that the noise and the torque ripple of the motor in operation are reduced. The method comprises the steps as follows: obtaining a three phase stator current signal, and the electrical angle and the electrical angular speed of the motor rotor through the technologies of sensor sampling and a photoelectric coded disc or position sensorless detection; carrying out Clarke transformation and Park transformation on the stator current signal to obtain the stator current in a synchronous revolution dq coordinate system; substituting the obtained stator current signal in the dq coordinate system into a control equation of a current predictive controller of the permanent magnet synchronous motor, carrying out deadbeat control according to the given value of the obtained stator current in the dq coordinate system in an outer ring controller to obtain a stator voltage vector in the dq coordinate system; carrying out Park inverse transformation on the obtained stator voltage vector in the dq coordinate system, to obtain a pulse-width modulation (PWM) control signal of an inverter by a space vector pulse width modulation (SVPWM) method, controlling the stator current through the inverter, and then implementing the current predictive control over the permanent magnet synchronous motor.

Description

technical field [0001] The invention relates to a current prediction control method of a permanent magnet synchronous motor, in particular to a permanent magnet synchronous motor used in variable frequency air conditioners, which is applicable to all permanent magnet synchronous motor models, and belongs to the field of electrical control. Background technique [0002] With the development of the permanent magnet material industry, permanent magnet synchronous motors have been widely used. Compared with asynchronous motors, permanent magnet synchronous motors have the advantages of high efficiency, high air-gap magnetic field density, and high power factor. Permanent magnet synchronous motor is mainly divided into two categories according to the induced electromotive force: permanent magnet synchronous motor (PMSM) and brushless DC motor (BLDCM). BLDCM has low cost, simple detection device and control, and large output torque. Under the condition of the same volume, BLDCM ha...

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Problems solved by technology

[0008] Therefore, in order to speed up the dynamic response speed of the permanent magnet synchronous motor, improve the control accuracy, and improve the problems of slow dynamic response speed and steady-state static error of the existing PID controller, it is necessary to design a current predictive control method for the permanent magnet synchronous motor. For permanent magnet synchronous motors, deadbeat control is adopted for the stator current to improve control speed and precision, and reduce torque ripple and noise

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