New level doubling architecture of cascaded multilevel inverter

Abstract

This study presents a new topology of single-phase cascaded multilevel inverter (CMLI). The proposed topology offers an optimised DC source utilisation, reduced switch count and curtailment of active switches in the conduction path for minimising power losses. It can produce almost twice the number of output voltage steps in comparison to the cascaded H-bridge, hence named level-doubling architecture, and can be operated as both symmetric and asymmetric CMLIs. Identical modules of proposed CMLI precludes requirement of a variety of semiconductors and provides ease for spare management. The modular design also facilitates mass production and enhances system reliability. Furthermore, the proposed topology can be easily extended to high-voltage applications. The proposed design is tested for its practicability by simulations in MATLAB/Simulink and results are verified by experimental set up of a scaled prototype single-phase model.