Варианты формирования симметричного семифазного выходного напряжения вентильного преобразователя

Abstract

A seven-phase bridge converter has 128 logical states. When a seven-phase symmetric winding is connected to the converter, each logical state produces a spatial-temporal resulting voltage vector. In total, the converter can produce 126 active vectors and 2 zero vectors. The aim of the work is to study and classify the vector space in implementing the converter control algorithms performing spatial-vector modulation of the voltage by a seven-phase symmetric winding. It has been determined that there are nine control algorithms that form a symmetrical seven-phase voltage with various phase voltage waveforms. Each waveform corresponds to a certain value of the phase voltage fundamental harmonic component. The fundamental harmonic amplitude corresponds to the modulus of the generalized spatial-temporal voltage vector of discrete states. The vector spaces of phase voltage vectors corresponding to the converter logical states and shaping the resulting vectors, and also the vector spaces of generalized voltage vectors are investigated. The numerical values of the resulting and generalized voltage vectors are obtained. In carrying out the study, the vector analysis methods and methods of expanding functions into Fourier series were used. The theoretical studies have been tested experimentally. The experiments were carried out on a bench intended for studying the spatial-vector modulation of multiphase motors using a prototype seven-phase motor. The results can be used to implement nonlinear vector control systems for a seven-phase motor.