Control system and method for suppressing current harmonics of permanent magnet synchronous motor

Abstract

The embodiment of the invention discloses a control system and method for suppressing current harmonics of a permanent magnet synchronous motor. The control system comprises a current sampling modulewhich samples a three-phase current in real time; a current coordinate transformation module which is used for transforming current coordinates; a low-pass filtering processing module which is used for processing a DC component; a fuzzy control decision module which is used for performing calculating to obtain a harmonic compensation voltage; a voltage coordinate conversion module which is used for converting harmonic compensation voltage coordinates; a harmonic compensation voltage injection module which is used for superposing a reference voltage to obtain a final reference voltage signal; and an SVPWM module which modulates the final reference voltage signal and injects the final reference voltage signal into the motor. According to the method, a fifth harmonic component and a seventh harmonic component in a current fundamental wave can be detected in real time, the corresponding harmonic compensation voltages are calculated and injected into a final reference voltage vector, so theeffect of suppressing the current harmonic of the permanent magnet synchronous motor is achieved, the fuzzy control strategy has higher robustness for a nonlinear time-varying system, and the controlperformance of the motor is further improved.

Description

technical field [0001] The invention relates to the technical field of motor control, in particular to a control system and method for suppressing current harmonics of a permanent magnet synchronous motor. Background technique [0002] Permanent magnet synchronous motors have the advantages of simple structure, high power density, and high efficiency, and are widely used in various industrial transmission fields, such as electric vehicles, robots, and CNC machine tools. However, due to factors such as the dead time of the inverter, the voltage drop of the tube, and the non-sinusoidal waveform of the back electromotive force of the motor, the stator current contains a large amount of high-order harmonic current, and the 5th and 7th harmonics account for a large proportion. The existence of harmonics will increase the loss of the motor, and at the same time, the output torque fluctuation will increase and the noise of the motor will increase, which will make the system control...

AI Technical Summary

Problems solved by technology

Its shortcoming is that the nonlinear system theory is not yet mature, and the parameters of the observer and regulator are not easy to tune, which will lead to poor system stability and robustness; the harmonic PI suppression strategy based on coordinate transformation uses the method of coordinate transformation to convert the harmonic The wave current is generated from the original current signal through the PI regulator to generate a compensation

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