Study on the fault current transient features of the PV inverter

Lots of studies has presented the steady-state fault features of the photovoltaic (PV) power generator and indicated that the PV power generator can be equivalently replaced by its steady-state fault current model for the fault analysis. However, the disturbance caused by the grid fault is so large that the output of the PV inverter would be saturated, which means the controller of the PV inverter would operate in nonlinear area. Consequently, the fault current transient features of the PV power generator are very complicated and much different from the steady-state fault characteristics. Aimed at it, the fault current transient features of the PV power generator are studied comprehensively in this paper, by taking the non-linearity of the PV inverter controller into consideration. The research results of this paper are of great importance for the establishment of equivalent model of PV power generator and fault analysis of the power grid with PV power generators.