基于NLM策略的模块化多电平换流器研究

Research on Modular Multilevel Converters Based on NLM Strategy

中文关键词:  模块化多电平换流器；最近电平逼近调制；电容均压  谐波含量

英文关键词:modular multilevel converter  nearest level modulation  capacitor voltage-sharing  harmonic content

中文摘要:

      介绍了模块化多电平换流器的拓扑结构和工作机制，建立MMC数学模型，将电容均压控制算法运用到不同调制策略中以实现电容电压的稳定。在Matlab-Simulink及RT-LAB半实物仿真平台下搭建7电平的逆变器仿真模型，验证最近电平逼近调制的优势。结果表明最近电平逼近调制策略下换流器运行正常，输出波形质量高、谐波含量少、子模块电容电压波动小，在电平数较高的应用场合中具有较大的优势；并证明了Matlab-Simulink和RT-LAB仿真结果的一致性以及RT-LAB仿真效率的高效性。

英文摘要:

      The topology and working mechanism of modular multilevel converter(MMC) are introduced and mathematical model for MMC is established.The capacitor voltage-sharing control algorithm is applied to different modulation strategies to achieve the stability of capacitor voltage.In Matlab-Simulink and RT-LAB semi-physical simulation platform,seven level inverter simulation model is constructed,to verify the advantage of nearest level modulation.The results show that the converter operates normally in the nearest level modulation,output waveform is of high quality and has less harmonic content,sub-modules capacitor voltage is stable,circulation is small and more suitable for high level situation.The consistency of Matlab-Simalink and RT-LAB simulation results and high efficiency of RT-LAB simulation results are also proved.