Abstract: A dynamic model for a large scale grid-connected photovoltaic （PV） generation system was proposed. The model can help to regulate power effectively and improve the capability to do the low voltage ride through （LVRT）. The perturbation and observation （P&O） algorithm based on power change rate and the double-loop decoupling control strategy of real and reactive power were adopted for the photovoltaic system. By using the STATCOM system, the reactive power compensation and system voltage stability are implemented. The simulation result on system performance of IEEE 3-machine 9-bus test system verifies the validity of the proposed model.

Key words: grid-connected photovoltaic, large scale, system modelling, operation analysis