Zero sequence ring current suppression method for direct current bus-shared open-end winding asynchronous motor system

Abstract

The invention aims to solve the technical problems of obvious stator current distortion and zero-sequence ring current of the direct current bus-shared open-end winding asynchronous motor caused by pure suppression of the zero sequence ring current in a modulation strategy link and neglecting of non-linearity and counter electromotive force zero sequence component in the prior art; on the basis, the invention provides a space vector PWM modulation scheme with controllable zero sequence voltage; by performing active control on the zero sequence voltage of the direct current bus-shared open-end winding asynchronous motor system, suppression of the zero sequence ring current is realized; and meanwhile, use of a zero vector is avoided, so that the common-mode voltage of the open-end winding asynchronous motor system is lowered.

Description

technical field [0001] The invention belongs to the inverter control technology in the field of electrical engineering, and in particular relates to a method for suppressing zero-sequence circulating current in a common DC bus open-winding asynchronous motor system. Background technique [0002] Compared with the traditional single-inverter driven asynchronous motor speed control system, the common DC bus open-winding asynchronous motor system has the advantages of high fault tolerance, flexible topology, and low DC side voltage level. Based on this, the common DC bus open-winding asynchronous motor system has attracted more and more attention from the academic circle. [0003] Although the common DC bus open-winding asynchronous motor has a good application prospect, as a relatively new motor topology, it still faces many problems to be solved, one of which is the zero-sequence circulating current problem of the system. The zero-sequence circulating current of the system i...

AI Technical Summary

Problems solved by technology

[0011] (1) Schemes 1), 2), and 3) do not take into account the zero-sequence voltage component caused by the nonlinearity of the inverter;

[0012] (2) Schemes 1), 2), and 3) do not take into account the zero-sequence voltage generated by the zero-sequence component in the back electromotive force of the open-winding asynchronous motor;

[0013] (3) Scheme 4) Using two independent DC sources for power supply cuts off the zero-sequence circulating current loop, but increases the hardware size and cost of the system

[0014] (4) Zero vector is used in all four schemes, resulting in a large common-mode voltage in the open-winding motor system

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