Comprehensive analysis of current mitigation strategies for non-isolated photovoltaic inverter

Abstract

Out of consideration for sustainable development, photovoltaic power generation system has become a hot research issue in the future energy strategy due to its significant cleanliness and reproducibility. Meanwhile, playing an important role in connecting the PV cell and the grid, the non-isolated photovoltaic inverter not only has the ability to convert energy with great efficiency but also with low loss and cost. In that case, the non-isolated inverter is widely used in the production. However, the leakage current is a big challenge that should be addressed with caution. This paper focuses on the leakage current mitigation strategy and makes a comprehensive analysis of each topology. The author analyses the generation mechanism of leakage current based on the single-phase inverter circuit. After that, the common ground type inverter topology and the H-Bridge type inverter topology will be further analysed for their universal utilization. Specific topologies from the two types of inverters are under comparison based on several perspectives, ranging from the degree of leakage current suppression to the complexity of the circuit structure, from the difficulty of analysis to the economic performance of the inverter. In addition, some improvement measures are proposed.