Two-dimensional modulation technique with dc voltage control for single-phase two-cell cascaded converters

In this paper, a simple feed-forward modulation technique for single-phase two-cell multilevel cascaded converters is presented. All the possible switching states of the power converter are taken into account applying a two dimensional control region. The proposed technique uses the actual values of the DC-Link capacitor voltages to obtain output phase voltages and currents with low harmonic distortion with any dc voltage in the H-bridges of the cascaded converter. The possible switching sequences of the converter are studied and, depending on the actual dc voltage values, their desired values are achieved. Simulation results are shown in order validate the proposed technique working as a synchronous rectifier.