A New Topology of Single-Phase Transformerless Inverter for Reducing Leakage Current of Grid-tied Photovoltaic Systems

This paper is about a novel transformer-less grid connected single-phase photovoltaic inverter. Now-a-days fossil fuels are in scarce. So, renewables are the only way to fulfill the increasing energy crisis. Solar energy, tide energy, wind energy are different sources of renewable energies. Among those, solar energy is most reliable, cost-free, simple processing and mostly available energy source. The inverter topology described in this paper converts the dc power captured in photovoltaic cells to ac power and supplies it directly to the grid. The grid voltage and current THDs are kept below 2%; extensive leakage current flow has been controlled; and power quality is much improved by this unique inverter topology. The power switches have been controlled using SPWM in addition to unipolar control. However, the common mode voltage has remained constant, which has also helped to lower the leakage current to 7.205mA. In this topology with an LCL filter, eight super junction IGBTs and six diodes have been employed. With the help of simulation findings, the leakage current suppression has been thoroughly examined. The switches decreased the leakage current but had little impact on efficiency. This topology has been verified through MATLAB/Simulink software environment.