Topologies Analysis of Transformerless PV Inverters with Leakage Current Reduction

Photovoltaic inverters concentrate much of the intelligence and control over the operation of the grid-connected photovoltaic system. The use of transformers in your topology reduces system performance, increases the weight, size and cost of inverters. Thus, the use of transformerless inverters is favored, especially in low power applications, where a low cost, light and efficient system is desired. However, the use of topologies without transformer generates some problems, the main one being the leakage through parasitic capacitances, intrinsically present in photovoltaic modules. High leakage current circulating in the system degrades power quality injected into the electrical grid and causes the activation of protections improperly, putting jeopardize the safety and reliability of the system. In this sense, this work performs an analysis, through simulations in a MATLAB/Simulink environment, of topologies of transformerless single-phase inverters that can deal with leakage current.