A Novel Hybrid Multilevel PWM Technique for Power Rating Enhancement in Improved Hybrid Cascaded Diode Clamped Multilevel Inverter

Abstract

In this article, an improved hybrid topology called cascaded diode clamped half bridge multi-level inverter is proposed upon a conventional cascaded H-bridge (CHB) multi-level inverter (MLI) which has the limitation to withhold a specific cell voltage due to the constraint on the device voltage stress. The proposed topology will ensure the enhancement of cell voltage capability double times, reduces the device stress, modularity in structure, and allows even power distribution. As a result, the user can now integrate two numbers of active dc sources to a cell. This ensures the efficiency of power enhancement in the applications like on/off grid-connected renewable energy system which require the power to be converted from dc to ac or vice versa. The proposed topology is compared extensively with the conventional CHB MLI at different loads. Hybrid pulse width modulation technique allows to operate the individual half bridge. The simulation and experimental results confirm the performance and efficiency of this proposed topology. A mathematical model of the proposed topology has been derived for the better feasibility of this topology extension to various other applications.