Six-phase alternating current motor harmonic current control strategy

Abstract

The invention relates to a six-phase alternating current motor harmonic current control strategy. Negative-sequence five-time and positive-sequence seven-time harmonic current detection and loop control are added on a conventional three-phase alternating current motor control method. A locking phase of a first stator not only outputs a magnetic chain angle and a magnetic chain frequency of the first stator and the negative-sequence six-time angle and the positive-sequence six-time angle are added. According to the design phase errors of the two stators, the magnetic chain angle of the second stator and the negative-sequence six-time angle and the positive-sequence six-time angle of the second stator are output; afterwards, according to features of two stator currents on a synchronous rotating reference frame, the negative-sequence five-time current components and the positive-sequence seven-time harmonic current components of stator currents are decomposed. Loop control is carried out on the negative-sequence five-time currents and the positive-sequence seven-time currents. A control result is converted through coordinates and stacked on the synchronous rotating reference frame, and the base wave currents are used for controlling the output base wave control voltage. Afterwards, the control result undergoes inverse transformation of synchronous rotation coordinates, a PWM module outputs pulse-width waves and a corresponding converter power unit composed of power electronic components is controlled.

Description

technical field [0001] The invention relates to a harmonic current control method of a six-phase AC motor. Background technique [0002] In recent years, with the increasingly serious problems of energy shortage and environmental degradation, the utilization of renewable energy, especially wind energy, has been paid more and more attention. Among the numerous wind power generation schemes, doubly-fed units and full-power units are two common models. Full-power wind turbines use permanent magnet or electric excitation synchronous alternators as power conversion devices, and are flexibly connected between the generators and the grid through full-power converters, which have good grid adaptability and a wider speed range. It is beneficial to the use of wind energy with small wind speed, and is more and more favored by domestic and foreign fan manufacturers. [0003] The single-unit capacity of wind turbines is increasing, but the output voltage and current of the converter ar...

AI Technical Summary

Problems solved by technology

In this way, it is difficult to achieve compatibility between the six-phase (also known as the stator double-winding difference of 30 degrees) AC motor and the double-winding three-phase (stator double-winding no phase difference) AC motor control program, which increases the workload of converter software development and maintenance

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