A method and device for suppressing harmonic current of permanent magnet synchronous motor

Abstract

The invention provides a harmonic current suppression method and device of a permanent-magnet synchronous motor. The method comprises the steps of obtaining d-axis current deviation and / or q-axis current deviation of to-be-suppressed harmonic current; and extracting a to-be-suppressed harmonic current signal by using a fourier analysis method, then carrying out filtering and superposition, simultaneously carrying out angle compensation on an electrical angle of the motor and carrying out signal reconstruction by the electric angle and the harmonic current signal to obtain output of a repetitive controller; the repetitive controller and a PI controller form an overall current controller to act on vector control of the permanent-magnet synchronous motor. The harmonic current suppression method is simple in logic, only simple repetition is needed when different harmonic current is suppressed, and the size of the harmonic current can be well suppressed, thereby achieving the targets of suppressing torque pulsation and improving the torque control accuracy and meeting the application of the high-performance permanent-magnet synchronous motor in the field of an electric vehicle and the like.

Description

technical field [0001] The invention relates to the technical field of automobiles, in particular to a method and device for suppressing harmonic current of a permanent magnet synchronous motor. Background technique [0002] Due to the advantages of high power density, low moment of inertia, and high efficiency, permanent magnet synchronous motors are more widely used in high-performance motion control applications, such as aerospace, precision machine tools, direct drive of robots, and recently, very rapidly developing electric vehicles fields etc. [0003] Torque smoothing is a fundamental requirement in these areas. Ideally, the permanent magnet synchronous motor can produce a smooth instantaneous torque waveform, but due to the cogging torque of the motor, the air gap flux harmonics, the dead time of the switching power device of the motor controller and the tube voltage drop, the current sensor Due to the calibration error and other reasons, a considerable part of the...

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Problems solved by technology

However, these methods are not enough in terms of system stability, and do not consider the influence of switching frequency on repetitive control when the motor is running at high speed. When the motor running speed increases, its harmonic suppression effect is limited.

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