Space vector pulse width modulation method for six-phase variable-frequency power source

Abstract

The invention discloses a space vector pulse width modulation method for a six-phase variable-frequency power source, which comprises the following steps 1), a six-phase / two-phase coordinate transformation matrix is used for mapping sixty-four switching states of a six-phase voltage source inverter to a dq sub-plane, a z1z2 sub-plane and an o1o2 sub-plane, and sixty-four fundamental voltage space vectors are obtained, wherein four zero vectors are included in the sixty-four vectors; 2), twelve vectors with the maximum amplitudes in the sixty-four vectors are selected from the dq sub-plane, and twelve new vectors are constructed according to a principle that voltseconds of the z1z2 sub-plane and o1o2 sub-plane are zero; 3), expected vectors are synthesized in the dq sub-plane by using the twelve new vectors and the zero vectors, and the action time of fundamental vectors corresponding to the new vectors is determined; and 4), action sequences of the fundamental vectors corresponding to the new vectors are determined according to a design principle that the switching times of the six-phase voltage source inverter is least and an output voltage waveform is in a 1 / 2 periodically symmetrical state. The method can be applied to modulation of the output voltage waveform of a multi-phase variable-frequency power source; the switching loss of the inverter can be reduced; load harmonic current can be inhibited.

Description

technical field [0001] The invention belongs to the field of power electronic system control engineering and relates to a space vector pulse width modulation method for a six-phase variable frequency power supply. Background technique [0002] The variable frequency power supply is generally three-phase, because the power system is three-phase, and most of the electric loads are also three-phase. With the development of power electronics technology, multi-phase power supply can be realized through power converters. The load of multi-phase power supply is generally multi-phase motor. At present, it is mainly used in high-reliability electrical drive fields such as aerospace, ship propulsion, and electric vehicles. The six-phase frequency conversion power supply is a representative special power supply in the multi-phase power supply. The main circuit is generally an AC-DC, voltage source type, two-level frequency conversion circuit. [0003] The modulation technology of the ...

AI Technical Summary

Problems solved by technology

The algorithm looks at simultaneously controlling the dq subplane and the z 1 z 2 The volt-second balance of the sub-plane, but the calculation amount of directly solving the five-variable linear equation system is relatively large. As the number of motor phases increases, the calculation amount of the equation system will increase significantly

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