Modular multilevel converters using split wound coupled inductors

The topology of modular multilevel converters (MMC) is investigated in this paper. First, single phase half bridge inverter with split wound coupled inductors was studied, it was found that more voltage levels can be generated by using split wound coupled inductors. Therefore, new MMC topology was proposed by the analysis result, therein, two more diodes were used for each arm, and split wound coupled inductors were applied to the modular multilevel converter (MMC) to replace the current-limiting inductors. The theoretic analysis and simulation results have verified that, the number of the voltage levels of modular multilevel inverter has increased from n levels to 2n-3 levels, thus slew rate of the voltage (dv/dt) was suppressed and the total harmonic distortion (THD) was reduced.