大功率NPC/H桥变流器控制策略研究

Investigation on the Control Strategy of High Power NPC/H Bridge Inverter

超大容量电力电子变频器广泛应用于油气输送、液化天然气、抽水蓄能等大功率工业领域,为实现高电压输出,中点箝位NPC/H桥多电平拓扑结构是最常用的解决方法。这里对NPC/H桥5电平变频器的工作原理和拓扑结构进行了分析,研究了基于载波的正弦脉宽调制(SPWM),通过PSIM软件仿真,验证了控制策略的正确性。对不同调制方式的优缺点和输出电压的谐波进行分析,给出了调制波移相调制方式的样机实验结果,并应用到基于IGCT的15 MVA NPC/H桥5电平变频器中。

Large power electronic converters are widely used in the oil and gas transportation, liquefied natural gas compressors, pumped storage and other fields.In order to achieve higher vohage,neutralpoint clamped NPC/H bridge multi-level topology is the most common solution.The topology of NPC/H bridge five-level converter and sine pulse width modulation（$PWM） are investigated.The PSIM simulation results validate control strategies correctly.The advan- tages and disadvantages of different modulation methods and the harmonics of output valtage are analyzed.Finally, the prototype adopts modulation wave phase shift method and experimental results are given.