Aggregated modelling of wind parks in power system dynamics simulations

Increasing numbers of wind turbines are connected to electrical power systems, in order to reduce the adverse environmental impact of conventional electrical power generation. A tendency can be observed to erect these turbines in wind parks, connected to the high voltage transmission grid. These parks effect the dynamic behaviour of power systems, because in wind turbines generator types that are different from the conventional synchronous generator are used. To investigate the impact of a wind park on the dynamics of the power system to which it is connected, an adequate model is required. In order to avoid the necessity of developing a detailed model of a wind park with tens or hundreds of wind turbines and their interconnections and to calculate the wind speed signal for each individual turbine, aggregated wind park models are needed. In the paper, aggregated models for wind parks equipped with either constant or variable speed wind turbines are presented. It is shown that results obtained with an aggregated model and with a detailed model show a high degree of correspondence, both for normal operation and for disturbances.