Abstract— Penetration of wind energy plants into power grids has been growing from installations with a few wind turbines to large wind farms with more than hundreds of MW capacity. Modeling of these wind farms with individual wind turbines increases the complexity of the model and consequently leading to long time for planning studies. Simplified models which simulate wind farms are usually used for performing grid connection planning studies to evaluate alternative scenarios. This paper presents an aggregation model for a 500 MW wind farm to simplify steady-state and transient simulation studies. The aggregated modeling converts each group of wind farm components into a single equivalent representation. These groups include generators, pad mounted transformers, collector system and station transformers. Results of simulation studies are presented to show comparisons of aggregated equivalent model and detailed model of the wind farm. The results include steady-state (power flow, short circuit, contingency) and transient analyses.