Dynamic equivalent modeling of FSIG based wind farm according to slip coherency

This paper applies the idea of coherency to induction generator, then presents a method called slip coherency to obtain the equivalent model of the wind farm with FSIGs. A criterion has been derived for slip coherency identification. A transformation of the entire internal network in the wind farm is discussed. This transformation should be carried out before aggregating the wind turbine generators, so that the entire internal network can be taken into account in equivalent model of the wind farm. Simulation results show that the transformation provides a satisfactory accuracy in both steady-state and dynamic process. The results also show that the equivalent model obtained by slip coherency method provides excellent accuracy as the detailed model.