A modified cascaded multilevel inverter with reduced switch count employing bypass diodes

In this paper, a bypass diode technique is introduced to the conventional H-bridge multilevel inverter topology that can reduce greatly the number of active switching elements in the system. Only one H-bridge is required for the entire single phase system, plus a transistor and a diode for each voltage source. A gradient search technique is employed to calculate the switching angles of the output waveform in order to achieve the minimum total harmonic distortion (THD). Single-phase experimental and 3-phase simulation results verify the concept development.