PUBLICATIONS

The modular multilevel converter (MMC) is generally considered to be a promising topology for medium-voltage and high-voltage

applications. However, in order to apply it to high-power applications, a huge number of switching devices is essential. The

numerous switching devices lead to considerable switching losses, high cost and a larger heat sink for each of the switching device.

In order to reduce the switching losses of a MMC, this paper analyzes the performance of the conventional discontinuous pulse-

width modulation (DPWM) method and its efficiency. In addition, it proposes a modified novel DPWM method for advanced

switching losses reduction. The novel DPWM scheme includes an additional rotation method for voltage-balancing and power

distribution among sub modules (SMs). Simulation and experimental results verify the effectiveness and performance of the

proposed modulation method in terms of its switching losses reduction capability.