A New H8 Transformer-less Single Phase Grid-tied Solar PV Inverter to Supress Leakage Current

Now-a-days, transformer-less grid connected solar photovoltaic (PV) inverters have attracted significant attention due to their special benefits such as higher efficiency, lower cost, and easy set up mechanism. A new transformer-less inverter topology with reduced leakage current and improved performances has been presented in this paper. This inverter circuit has been fabricated with eight semiconductor devices and an LCL filter at the output side. Three switches are used in the common mode voltage (CMV) clamping brunch to enhance inverter efficiency. In the freewheeling brunch, one switch is used so that the leakage current spikes get avoided. In the freewheeling mode common mode voltage is kept constant. While zero voltage state, CMV is clamped to half of the input voltage. The proposed inverter provides only a total of 10.18 mA leakage current. The grid current THD and grid voltage THD are found to be 1.42% and 0.37%, respectively. Unipolar SPWM method has been used to control the power switches. The behavior of the proposed TLPV inverter is verified via simulation analysis performed at MATLAB/Simulink environment.