A modified T-type single phase five-level inverter with reduced switch voltage stress

Abstract

In this paper, two new three level inverter legs are derived by modifying the conventional three level T-type topology with common emitter and common collector configurations respectively. The modification allows the reduction of one switching stress per inverter leg as compared to T-type counterpart through increased current sharing in the switching device. The concept can be extended to increase the inverter voltage levels by adding extra half bridges at top and bottom. The modulation control of the modified T-type multilevel inverter legs is similar to its counterparts and therefore straight forward and easy to implement. Other characteristic of the inverter is less components count in the current flow path there by facilitating reduction in the power loss. Multilevel-Multiphase systems can be realized by any of these modified inverter legs or all possible combinations of them. A single phase five-level inverter topology formed by the two modified T-type three level bridge legs is studied in detail with the help of simulation results for validation of the proposed approach.