Analysis of current distortion for single phase PV system with isolated transformer

This paper discusses the current distortion of the single phase photovoltaic (PV) system with an isolated transformer. Many methods are proposed with respect to their capabilities to limit the voltage rise within a balanced low voltage system with a high level of PV penetration. Due to reactive power flow and excitation impedance characteristics of the transformer, the current distortion of the grid-connected inverter occurs at the V-Q control. Simulation and experimental results agree with the theoretical analysis well. Finally, a method was proposed to reduce the distortion of the output current,which provides a reference for the engineering designer.