Dynamic simulations of wind generators connected to distribution systems

The total wind power installed in the world grew since 1992, from 2.5 GW to 40 GW in 2004 (30% per year). The industry esteems 75 GW for 2010, wich is equal to 167 TWh per year. This tendency leads to modifications in the electric systems behavior and to the necessity to take into account this new grid profile in dynamic analysis of electric systems. This work presents a methodology developed for dynamic analysis of wind generators connected to distribution systems. It presents wind turbines mechanical model, wind generators models and control strategies. The methodology has been applied to the CELPE Distribution System, brazilian distributing of electric energy, using a transient stability software ESTABEOLICA^©, implemented on this work. Two types of induction machines have been considered to model wind generators: squirrel cage induction generator (SCIG) and doubly fed induction generator (DFIG). It emphasizes voltage and reactive power control at the DFIG machines and electric power behavior when wind speed variations occur.