Methods to Improve Suppression of Leakage Current Generation in Single-phase Non-isolated Photovoltaic Grid-connected Inverters

Abstract

Analysis of methods to suppress leakage current through the topology of a single-phase inverter is carried out, aiming to address the phenomenon that disturbs the normal operation of electrical equipment and poses risks to human life when equipment integrates the electrical system into the grid. The topology of a single-phase inverter is taken as the research object, whose issues will be researched and summarized. First of all, by analyzing the single-phase inverter circuit, a simplified equivalent circuit is obtained. Then during the simplification process, it can be concluded that the generation of leakage current is related to the rate of change of common-mode voltage. After that based on this phenomenon, the general direction for suppressing leakage current has been obtained: when the electrical equipment links to the grid: keep Vcm constant, and four clear methods to suppress leakage current. Then reanalyze the way some new non-isolated grid-tied inverter topology how to suppress leakage current. Eventually, the conclusion would be reached.