A fast three-phase space vector modulation method in two-dimensional coordinate system

Abstract

The invention provides a three-phase space vector rapid modulation method in a two-dimensional coordinate system, which belongs to the technical field of power electronic modulation. This method transforms the traditional three-phase two-dimensional coordinate system into a new two-dimensional rectangular coordinate system, and obtains the remaining two vectors of the modulation triangle by directly checking the vector closest to the origin, which has strong scalability. In addition, this method can provide several controllable factors, and the factor N can be used as an optimization target to weaken the common-mode voltage and select redundant vectors for voltage equalization; the controllable switching sequence produced can ensure the smooth transition of vectors in the modulation triangle and between modulation triangles To reduce the overall switching frequency of the system to reduce switching loss and optimize harmonic performance; adjustable zero-vector duty cycle can also optimize harmonic performance, synthesize a more ideal flux linkage circle to output high-quality sine waves and ensure the same voltage as the factor N balanced. The function of this method reflects its superior application value and good application prospect.

Description

technical field [0001] The invention belongs to the technical field of electric power electronic modulation. Background technique [0002] Space vector modulation (SVPWM) is a pulse width modulation method based on the concept of space voltage vector synthesis, which has been widely used in power electronic modulation. Its core idea is to use the different switching states of the converter as the basic action vector, and synthesize the reference voltage vector according to the selected basic vector and its specific action time. Compared with the ordinary PWM modulation algorithm, it has many outstanding advantages: high voltage utilization rate, easy digital realization, good output waveform quality, close to sinusoidal, reasonable arrangement of space vector, can reduce switching frequency, reduce switching loss, and use SVPWM The redundant vector of the multi-level converter can realize the voltage balance of the multi-level converter, can eliminate the common mode voltag...

AI Technical Summary

Problems solved by technology

However, it is still necessary to list the vectors one by one in the vector allocation, and it is still not easy to expand, and these algorithms have a single function and can only realize the basic synthesis of the reference voltage vector, and have no outstanding contribution to optimizing the performance of other aspects of the multi-level converter.

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