Transformerless PV Inverter Topology Using HB-ZVR

There is a strong trend in the photovoltaic inverter technology to use transformerless topologies in order to acquire higher efficiencies combining with very low leakage current. Here a new topology based on the H-bridge with a new ac bypass circuit consisting of a diode rectifier and a switch with clamping to the dc midpoint is proposed. This topology offers high conversion efficiency and a low leakage current is obtained. This will help to reduce the space also and the overall weight can be reduced because here we are not using any transformer.The efficiency of commercial PV panels is around 15-20%. Therefore, it is very important that the power produced by these panels is not wasted, by using inefficient power electronics systems. The efficiency and reliability of both single-phase and three-phase PV inverter systems can be improved using transformerless topologies, but new problems related to leakage current and safety need to be dealt with.