新型不对称多电平逆变器拓扑及其调制策略

Novel topology and modulation strategy to asymmetric multilevel inverter

传统多电平逆变器应用在高电压等级场合时,所需要的电源以及开关管的数量较大,拓扑结构也较为复杂。针对以上问题,提出一种新型的不对称多电平逆变器拓扑,该拓扑使用了3个不对称的独立电源。与传统的拓扑对比,输出十五电平电压条件下,该拓扑使用开关管器件数量较少,简化了拓扑结构,同时降低了实际成本。采用一种改进的载波移幅调制策略调制该新型不对称拓扑结构,使其能够正常地输出十五电平电压波形,该方法保留载波移幅调制的方法简单且谐波含量少的优点,同时也减少了载波数量的使用。最后对所提拓扑结构及其调制策略进行了仿真分析和实验验证,结果表明了拓扑结构及调制策略的正确性、可行性和优良的动态性能。

When the traditional multilevel inverter is applied to high voltage level,the number of power supply and switch tube required is large,and the topology structure is also more complex.To solve the a-bove problems,a new asymmetric multilevel inverter topology was proposed,which uses three asymmetric independent power supplies.Compared with the traditional topology,under the condition of outputting fif-teen level voltage,in this topology less switching tube devices were used,the topology structure was sim-plified and the actual cost was reduced.An improved carrier amplitude shift modulation strategy was used to modulate the new asymmetric topology structure so that it can normally output a fifteen level voltage waveform.The method maintains the advantages of simple carrier amplitude shift modulation method and low harmonic content,and reduces the use of carrier number.Finally,simulation analysis and experi-mental verification of the proposed topology and its modulation strategy were carried out.The simulation and experimental results show that the proposed topology and its modulation strategy are correct,feasible and have good dynamic performance.