Capacitor balancing of a modular multilevel inverter using a modulation strategy

The Modular Multilevel Inverter (MMI) is a new solution for medium and high voltage, and high power applications. It consists of certain modules, each being a half-bridge parallel to a capacitor. The special characteristic of Modular Multilevel Inverter is its ability to build near sinusoidal voltage waveform by adding several modules in each phase-leg of the inverter. At the beginning, basic concept about the modular multilevel inverter and the control scheme are introduced in detail. Then, the capacitor voltage balancing of modular multilevel inverter with the help of phase disposition level shifted PWM are explained and simulated using MATLAB/simulink.