Single phase transformerless inverter for grid connected photovoltaic system with reduced leakage current

Abstract

Introduction. Transformerless inverters are of vital importance in the field of grid connected solar photovoltaic systems offering higher efficiency than the conventional one. i.e., using transformer. General grid connected inverters are constituting of transformers requires more area besides the loss in them. Problem. Eliminating transformers can cause leakage current due to the variation of common mode voltage which in turn due to parasitic capacitance effect. Research literature in transformerless inverters has addressed the problems of common mode leakage current issues by offering the study of different inverter topologies like H4, H5, H6 and HERIC etc. utilizing variety of modulation strategies like unipolar, bipolar pulse width modulations. Goal. The paper significantly presents a new transformerless inverter topology, analyzes common mode voltage and leakage current behavior of the system. The simulation is carried out for comparing the leakage current profiles with other transformerless inverter topologies in literature. Novelty. This paper gives an impression of the efficient transformerless inverter for grid connected photovoltaic system. Results. The various inverter topologies full bridge with different pulse width modulation techniques are analyzed and to determine the common mode voltages and leakage currents.

Keywords

• transformerless inverter
• leakage current
• photovoltaic system