A single-sourced transformer-less asymmetric multi-level inverter

This paper proposes a power conditioning system (PCS) using an asymmetric cascaded multilevel inverter with a single PV source. One of the main disadvantages of cascaded multilevel inverters in PV systems is the requirement of multiple isolated DC sources. The proposed PCS uses a single PV source with a dual inductor DC-DC converter to facilitate the reduction of the required DC sources and maintain voltage balance during the operation. The dual inductor buck converter is used to provide the input for low-voltage upper H-bridge cell which processes only 20% of the total power. This helps to minimize the losses occurring in the proposed PCS. Furthermore, the dual inductor can successfully block the leakage current without any transformer. The feasibility of the proposed PCS and its control scheme has been tested using a 500W hardware prototype and the obtained results are presented.