基于CO-SFO-PWM级联型多电平逆变器的研究

摘要

The article selects the cascade multilevel topological as the topological structure of the cascaded mediumhigh voltage converter, and focuses on the multi-level inverter circuit and pulse width modulation (PWM) technology, analysis the working principle of cascade nine-level inverter. Also,new CO-SFO-PWM technology is used to have a simulation on cascade nine-level inverter. The experimental results show that the new PWM technology can significantly improve quality of the output wave at low modulation ratio, and has low THD of the output wave at high modulation ratio, moreover, it can increase utilization of DC-side voltage.%选取级联型多电平拓扑作为中高压变流器的拓扑结构,对多电平逆变电路及其PWM技术进行了研究,并对级联型9电平逆变器的工作原理进行了分析.采用新型CO-SFO-PWM技术进行级联型9电平逆变器实验,实验结果表明该新型PWM技术不仅在低调制度下可明显改善输出波形,而且在高调制度下同样可获得较低的THD的输出波形,并且提高了直流侧电压利用率.