Enhanced-Boost Bidirectional Quasi-Z-Source Inverter With Novel Active Switched Inductor Cells

The conventional Z-source inverter (ZSI) has the following disadvantages: unidirectional power flow, high startup inrush current, presence of undesirable mode operation, and low boost factor. To solve the aforementioned shortcomings, an enhanced-boost bidirectional quasi-ZSI (QZSI) with novel active switched inductor (SL) cells (named Active-SLs QZSI) is proposed. The proposed active SL cell replaces three diodes in the conventional SL cell of the QZSI with two capacitors and one active switch, thus allowing bidirectional power flow and achieving higher boost factor. In addition, the Z-source network (ZSN) diode is also replaced by an active switch. Compared with the existing ZSIs, the proposed Active-SLs QZSI has less current stress of ZSN, higher efficiency, and higher boost factor. A modified space vector modulation (MSVM) is introduced to reduce the switching frequency of active switches of ZSN. Both the simulation and experimental results validate the theoretical analysis of the proposed Active-SLs QZSI.