A Novel Aggregation Technique Using Mechanical Torque Compensating Factor for DFIG Wind Farms

Abstract

A novel aggregated model for wind farms consisting of wind turbines equipped with doubly fed induction generators (DFIG) is proposed in this paper. In the proposed model, a mechanical torque compensating factor (MTCF) is integrated into a full aggregated wind farm model to deal with the nonlinearity of wind turbines in the partial load region and to make it behave as closely as possible to a complete model of the wind farm. The MTCF is initially constructed to approximate a Gaussian function by a fuzzy logic method and optimized on a trial and error basis to achieve less than 10% discrepancy between the proposed aggregated model and the complete model. Then, a large scale offshore wind farm comprising 72 DFIG wind turbines is used to verify the effectiveness of the proposed aggregated model. The simulation results show that the proposed model is able to approximate collective dynamic responses at the point of common coupling with significant reduction in the simulation computation time.