Two new magnetically coupled-inductor Z-source inverters with high voltage boost capability

摘要

This paper proposes two new high voltage boost inverters, which are based on the traditional magnetically coupled-inductor Z-source inverters (ZSI). Both proposed topologies provide a continuous input current and a higher boost ability compared to the most existing Z-source inverter-based topologies. The first proposed topology named extended boost switched-coupled-inductor-ZSI (extended boost SCL-ZSI) has been derived from the improved trans-ZSI and the switched-coupled-inductor-ZSI. By adding extra passive components, this new inverter provides a significant high voltage gain. The other proposed topology, which is named active-switched-capacitor/switched-coupled-inductor Z-source inverter (ASC/SCL-ZSI), achieves high boost ability and low voltage stress across the switching devices of the main inverter bridge. On the other hand, the both proposed inverters provide continuous DC input current and suppression of resonant current at startup, which may result in destruction of the switching devices due to voltage and current spikes. In order to investigate the performance of the proposed topologies, a comprehensive comparison between the two proposed inverters as well as some existing Z-source structures, in terms of boost ability, number of components and voltage and current stresses is made. Both the analytical and simulation results validate proper operation and performance of the proposed schemes.