A novel symmetric switched capacitor multilevel inverter using non-isolated power supplies with reduced number of components

Abstract

In this paper, a novel 15 level symmetric switched capacitor multilevel inverter (SCMLI) structure is proposed first. The structure is developed by using 3 non-isolated DC power sources. The capacitors utilized in the structure can be charged to the summation of all the power supplies by turning ON the minimum number of switching devices. After that a generalized structure of the proposed SCMLI is developed. The voltage and current stresses for different switches of the proposed general structure are discussed. The selection procedure of switched capacitors for the proposed 15 level inverter is presented for resistive and resistive-inductive load conditions. A detailed comparison study of the proposed structure with other recently developed structures shows that the proposed structure requires reduced number of components and the number of switches in the conducting path as compared to other SCMLI structures for generating an output voltage level. Further, the overall cost of the proposed and suggested topologies has been compared based on a cost function (CF). It has been observed that the proposed structure is more cost effective as compared to others. An extensive experimental study conducted on a 15 level SCMLI laboratory prototype proves the effectiveness and merits of the proposed structure.