Modeling wind farms for power system stability studies

Wind energy conversion systems comprise mechanical and electrical equipment and their controls. Modeling these systems for power system stability simulation studies requires careful analysis of the equipment and controls to determine the characteristics that are important in the timeframe and bandwidth of such studies. Just as important, the characteristics must be reviewed to put aside factors that can be important for wind turbine/wind farm design but do not play a decisive role for the wind turbine/wind farm response from a system standpoint or whose characteristics are not relevant to the frequency range typical for power system stability performance. With this in mind, models of wind turbine units and wind farms are being developed for a commercial power system load flow and stability simulation package. All significant air-dynamical, mechanical, and electrical factors have been reviewed and are modeled appropriately. Load flow models allow aggregation of wind farms comprising tens to hundreds of wind turbine units and easy addition of an equivalent of the wind farm to the model of the existing system. Dynamic models represent different types of constant speed and variable speed technologies currently employed by manufacturers, with their controls.