Performance Analysis of a High Gain Quasi Z-Source Network Based Cascaded H-Bridge Multi-level Inverter

This paper presents a High Gain quasi-Z-Source Network (HG-qZSN) integrated with Cascaded H-Bridge Multi-level Inverter (CHB-MLI) used for renewable energy source applications. The proposed system consists of two quasi Z-source switched capacitor networks and five-level CHB-MLI with eight power switches. The proposed five-level CHB-MLI uses a two HG-qZSN for DC-DC conversion which gives a very high voltage gain or boost factor when compared to conventional boost converters. A five-level CHB-MLI can have the superior performance using sine Pulse Width Modulation (PWM) which is used for DC-AC conversion to provide an efficient conversion and hence suitable for renewable energy applications. In addition, the proposed HG-qZSN based CHB-MLI has modular circuit layout and can be easily extended to higher levels. Simulations are carried out for five-level HG-qZSN based CHB-MLI using MATLAB/Simulink for different duty cycles i.e., 0.2, 0.3 and 0.4. The presented results support the theoretical analysis with a high gain or boost factor of 3, 4.25 and 8 for the 0.2, 0.3 and 0.4 duty cycles respectively.