对于多电平变流器的研究,无论是电压型还是电流型多电平变流器,大多集中在拓扑结构以及相应的开关控制策略方面.为了更好地理解电流型多电平变流器多电平电流产生的内在机理,该文借助于开关变换器的一些建模方法,以一种新型单相5电平电流型变流器为例,建立了其稳态平均模型,推导出了各支路电流的数学表达式并进行了定量分析.仿真和实验结果均验证了该种数学建模方法的正确性.
Researches of multilevel converters, whether for multilevel voltage-source inverters (VSI's) or multilevel current-source inverters (CSI's), were mainly focused on topologies and switching control strategies. In order to understand the intrinsic mechanism of multilevel current generation for multilevel CSI' s, in this paper, based on a new kind of single-phase 5-level CSI, the steady-state mathematical model was set up by using some kinds of switching converter modeling methods, the mathematical expressions of the current related to each branch was achieved and the quantitative analysis was presented. Lastly, the results of digital simulations and experiments all validate the correctness of this kind of mathematical modeling.