三相交错级联变流器研究

Research of three-phase interconnected cascaded converter

针对常见的H桥级联变流器拓扑结构或需要多个直流电源、难以实现四象限运行,或成本高、控制算法复杂等问题,提出了一种三相交错级联变流器拓扑结构及其调制方案。该变流器由3个三相两电平变流电路两两错相联结而成,结构简单,直流电压利用率高;采用错时采样脉宽调制技术,降低了开关损耗和输出波形畸变率。Matlab/Simulink仿真结果表明,基于错时采样脉宽调制技术的三相交错级联变流器输出波形正弦度好,谐波含量低。

In view of problems that normal cascaded H-bridge converter needs multiple DC power supplies for topology and is difficult for realization of four quadrant running, or needs high cost and complicated control algorithm, a topological structure of three-phase interconnected cascaded converter is put forward with modulating solution. By every two phases interconnection of 3 three-phase two-level converting circuits, the converter has simple structure and high utilization efficiency of DC voltage; employing sample-time-staggered pulse-width modulation technology, and has lower switching loss and output waveform distortion. Matlab/Simulink simulation result shows that the three-phase interconnected cascaded converter based on sample-time-staggered pulse-width modulation has better sine wave and lower harmonic content for output waveform.