Transformer-less single-phase grid-tie photovoltaic inverter topologies for residential application with various filter circuits

This article presents an overview of different transformer-less single-phase grid-connected photovoltaic inverters with various filter circuits including immittance conversion topology for residential application. Various inverter topologies are presented, compared, and evaluated against components used, size, cost, self life, losses, and efficiency. To find the suitable topology, a number of factors are considered in the design of inverter: 1) the number of buck and boost stages in cascade; 2) the type of synchronization to align the PV output with the grid; 3) whether the inverter will be designed using a minimalist component strategy; 4) elimination of Total Harmonic Distortion (THD) and 5) efficiency. After a rigorous analysis, some of the topologies are pointed out as the best candidates for either single or multiple photovoltaic (PV) module applications.