Leakage Current Suppression Solutions for Photovoltaic Cascaded Multilevel Inverter Application
The cascaded multilevel inverter is considered to be a promising alternative for the low-cost and high-efficiency photovoltaic (PV) systems. However, the current leakage issue, resulting from the stray capacitances between the PV panels and the earth, needs to be solved for the cascaded inverter to be reliably applied in PV application.
The proposed technologies solve the leakage current issue in PV cascaded multilevel inverter by using passive filters. It can retain the simple structure of the inverter and does not complicate the associated control system. The system is a photovoltaic cascaded inverter, including inverter modules, which have both an AC and a DC side. In addition, the system includes a common DC-side choke coupled to the DC-side of each of the inverter modules and a common mode AC-side choke coupled to the AC-side of each of the inverter modules.