Open-winding six-phase inverter modulation method for inhibiting third harmonic and common-mode voltage

Abstract

The invention provides an open-winding six-phase inverter modulation method for inhibiting a third harmonic and a common-mode voltage. The method comprises the following steps: mapping a six-dimensional electromagnetic quantity of a six-phase motor into three orthogonal two-dimensional subspaces; obtaining frequency components corresponding to the orthogonal two-dimensional subspaces; mapping thethird harmonic component to o1-o2 subspaces according to the frequency components corresponding to the orthogonal two-dimensional subspaces, wherein the o1-o2 subspaces refer to zero sequence subspaces; controlling the plane projection of a voltage vector in the o1-o2 subspace to be 0; controlling the common-mode voltage of a six-phase inverter of an independent bus topology to be 0 so as to obtain a voltage vector used for PWM modulation; and controlling the open-winding six-phase inverter according to the voltage vector used by the PWM modulation. Therefore, the common-mode voltage and the third harmonic current of the open-winding six-phase permanent magnet synchronous motor can be suppressed at the same time, and the motor loss caused by the harmonic current is reduced while the common-mode voltage is suppressed.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to an open-winding six-phase inverter modulation method for suppressing third harmonics and common-mode voltage. Background technique [0002] Compared with the ordinary six-phase motor with independent neutral point, the open-winding six-phase motor will generate a large third harmonic current when the ordinary six-phase inverter modulation method is used, so a new PWM modulation method is required to suppress the third harmonic current Harmonic current. Also, since the windings of the six-phase motor are open, the neutral point no longer exists, requiring rejection of the common-mode voltage caused by the dual-inverter topology. The permanent magnet synchronous motor has the advantages of no excitation current, less stator current, copper loss, and rotor loss; the six-phase permanent magnet synchronous motor has higher fault tolerance, higher torque density, and smaller...

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Problems solved by technology

[0004] However, the above-mentioned common-mode voltage suppression scheme will cause a large third harmonic current and cause a large loss

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