The topology-based approach to leakage current suppression on transformerless photovoltaic inverters

Abstract

With the increase in demand for renewable energy, photovoltaic power generation is gradually becoming the most promising new energy source. However, the electrical connection of PV cells to the grid, and parasitic capacitance between the PV cell and the ground can introduce severe leakage currents into the grid. The scientific community has developed various topology-based techniques to suppress leakage currents. This paper is dedicated to a review of these techniques. Firstly the H5, HERIC, FB-DCBP, oH5, H8, and H6 are analyzed. These techniques are then reviewed more fully in terms of quality, efficiency, size, and complexity. All six of these topologies can meet the requirements for leakage current suppression, and there is an increasing trend toward reducing the size and simplifying topologies. Finally, future trends in topology-based techniques for suppressing leakage currents are predicted. The significance of this paper is that it provides a comprehensive review and summary of the various topology-based techniques for suppressing leakage currents.