A harmonic current decoupling control system and method for a convex synchronous motor

Abstract

The invention relates to a harmonic current decoupling control system and method of a convex synchronous motor. The system includes: a harmonic current detection module: obtaining 6k±1 order harmonic current feedback, k is a positive integer; a linear transformation module: converting the harmonic The 6k±1 harmonic current reference and the 6k±1 harmonic current feedback in the wave reference coordinate system are respectively linearly transformed to obtain a new harmonic current; the harmonic current decoupling control module: according to the linearly transformed harmonic current reference The error adjustment between the harmonic current feedback and the independent decoupling control of each harmonic current; the inverse linear transformation module: performs inverse linear transformation on the output voltage to obtain the control output voltage under the harmonic reference coordinate system; the motor control module: The control output voltage is used as the reference value of the output voltage of the convex synchronous motor to control its work. Compared with the prior art, the present invention realizes the dynamic decoupling control of the harmonic current, improves the control precision and response speed of the harmonic current, and simplifies the design of the decoupling controller by utilizing linear transformation.

Description

technical field [0001] The invention relates to the technical field of synchronous motor control, in particular to a harmonic current decoupling control system and method of a convex-level synchronous motor. Background technique [0002] Built-in permanent magnet synchronous motors are usually used as drive motors due to their advantages such as high efficiency, high power density, and wide speed range, and have been widely used in electric vehicles and other fields. However, due to the cogging effect of the motor, the back electromotive force distortion caused by the harmonics of the permanent magnet magnetic force, and the dead zone effect of the inverter, there is a harmonic current of 6k±1 times the fundamental frequency in the stator winding. If not controlled, harmonic current will cause additional copper loss and iron loss, and at the same time generate torque ripple, affecting motor efficiency, noise and torque output stability. [0003] The permanent magnet synchro...

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Problems solved by technology

However, the literature (Zhong Zaimin, Jiang Shang, Kang Jinsong, Chen Xueping, Zhou Yingkun, "Coupling Model and Feedforward Control of Harmonic Voltage and Current of Permanent Magnet Synchronous Motor," Journal of Electrotechnical Society, vol.32, no.18, pp.131 -142,2017.) pointed out that for the convex-stage permanent magnet synchronous motor, there is coupling between the positive and negative sequence harmonic currents of the same frequency, which affects the control performance of the harmonic current

The above-mentioned traditional harmonic current control method does not design a controller based on the dynamic equation of the harmonic current, ignores the dynamic coupling between the harmonics of the convex synchronous motor, and cannot realize the complete decoupling between the harmonic currents, thus affecting the harmonic current control Accuracy and Response Speed

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