Abstract
In this paper, we investigate operation of multiple solar photovoltaic (PVs) in utility grid integration and islanded microgrid. Two PVs are considered and the grid-supporting inverters are adopted for the two PVs. The PVs are able to work in both utility grid and microgrid with the same control scheme. The control scheme is based on the conventional P-f and Q-v droop control strategy. Smooth transition between grid connected to islanded mode is achieved. Moreover, we investigate the effect of load transients during stand-alone operation on PV performance, including dc side voltages. The investigation is carried out by computer simulation of two parallel-connected PV inverters in Matlab/SimPowerSystems environment. Two operation cases, grid-connected and transition to islanded mode, are presented.