【摘要】 模块化多电平换流器MMC(Modular Multilevel Converter)子模块电容电压的稳压控制是MMC的一个关键难题,在实际应用中,需要大量的电压传感器以获取各子模块电容电压。对此提出了一种电容电压滑模观测器SMO(Sliding Mode Observer),根据MMC电路中的桥臂电流和开关信号观测出子模块电容电压,并结合电压闭环控制,实现电容电压的稳定。采用双曲正切函数tanh作该滑模观测器的切换函数,可削弱系统抖振。仿真和实验结果表明该滑模观测器可准确观测出电容电压。更多还原

【Abstract】 Voltage balancing of sub-module capacitors is a key issue of Modular Multilevel Converter(MMC).In application,a large number of voltage sensors are needed to obtain sub-module capacitor voltages.A sliding mode observer(SMO)is presented,estimating sub-module capacitor voltages by measuring arm currents and gate signal,combining voltage closed-loop control,implementing the stabilization of capacitor voltages.Chattering in the system could be weakened by adopting tanh as switching function in the SMO.The simulation and experiment results validate that this SMO could accurately estimate capacitor voltages.更多还原