Photovoltaic (PV) solar power plants are under development worldwide in both concentrated and distributed ways.With further planning, increasing influences of both utility scaled and roof PV system on the grid stability, power quality and grid protection will not be neglected.The grid integration study for PV integration becomes therefore more important, while countries with large PV installations are extending and standardizing their requirements for PV grid connection.Simulation method for such grid integration study can be implemented to save the high cost of plant measurement and increase the accuracy.This paper shows the way to verify PV grid requirements and improve the intelligence of PV power plants to participate the grid system services.