A new cascaded multilevel inverter with reduced number of switches

This paper propose a new topology for cascaded multilevel inverters. This structure consists of series connection of proposed basic unit blocks which are built with both unidirectional and bidirectional switches. The proposed structure has some advantages including: reduction in the number of switches and driver circuits, cost and installation area. Three algorithms for determination of dc voltage sources´ magnitudes have also been proposed. The algorithms can produce all odd and even levels at the output voltage. The proposed structure also has fewer dc voltage sources variety and less maximum blocking voltage of switches compared to conventional inverters. The capability of proposed structure in producing all odd and even output voltage levels is proved by simulation result for a 21-level inverter.