Test-Based Modeling of Photovoltaic Inverter Impact on Distribution Systems

Open circuit, short circuit and voltage sag tests were performed on eight different photovoltaic (PV) inverters, over a range of power outputs and event points on wave. Overvoltages can exceed 2.0 pu peak and 1.9 pu first-cycle rms. Fault currents can exceed 3.9 pu peak and 1.1 pu first-cycle rms during a short circuit event, or 1.3 pu rms during a sag. Inverter type tests are proposed to characterize these parameters for modeling in system impact and hosting capacity studies. Example inverter models for the Alternative Transients Program and OpenDSS have been posted to web repositories.