中文说明：
载波移相SPWM调制法是一种特别适合于级联多电平逆变器的SPWM方法,在matlab/simulink环境下下运行。
English Description：
Carrier phase-shifting SPWM modulation method is a particularly suitable for SPWM method of cascade multilevel inverter, run up and down in the matlab/simulink environment.