SVPWM control method for reducing common-mode voltage of six-phase motor

Abstract

The invention provides an SVPWM (Space Vector Pulse Width Modulation) control method for reducing the common-mode voltage of a six-phase motor, which relates to the technical field of multi-phase motor control. Voltage vector selection in an SVPWM control strategy for reducing the common-mode voltage is carried out based on voltage vector redundancy in six-phase motor control. Four proper effective voltage vectors are selected from a large number of vectors, and zero voltage vectors causing great change in amplitude of the common-mode voltage are processed. Through the SVPWM control method for reducing the common-mode voltage of a six-phase motor provided by the invention, the common-mode voltage at a stator node can be reduced greatly under the condition that the harmonic is not increased.

Description

technical field [0001] The invention relates to the technical field of multi-phase motor control, in particular to a SVPWM (Space Vector Pulse Width Modulation, Space Vector Pulse Width Modulation) control method for reducing the common-mode voltage of a six-phase motor. Background technique [0002] Electric motors have been widely used in all aspects of production and life. With the continuous improvement of people's requirements for products and quality of life, there are higher requirements for electric motors as living and production tools. Multi-phase motors have the advantages of small pulsation, suitable for low voltage and high power, small harmonics, good fault tolerance, low noise and energy saving, etc., which have attracted more and more people's attention. At present, multi-phase motors are mostly used in aerospace, precision medical equipment, military, ships and ships, etc., which require high motor reliability and control accuracy. However, with the rise of ...

AI Technical Summary

Problems solved by technology

A contradiction faced in this way is that if the harmonics are to be reduced, the switching tube frequency of the inverter used is very high, but this will cause the voltage at the stator node to change rapidly and the common-mode voltage to increase

If the common mode voltage reaches the level of breaking down the insulating oil film on the bearing, bearing current will be generated, which will reduce the life of the motor, and this situation exists on various motors

Another problem faced by the traditional multi-phase motor control is that the method adopted is the adjacent maximum four-vector control method. According to the research, it is difficult to realize this method in one PWM cycle, and in one cycle, The voltage at the stator node changes many times, and if a frequency converter with a high frequency is used, a large common-mode voltage will be generated

For the traditional control of multi-phase permanent magnet motors with two adjacent vectors, the harmonic plane voltage vector synthesis voltage vector is large, and large harmonics will be generated

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