Model aggregation of large wind farms for dynamic studies

A large number of nodes is required for the detailed simulation of large off-shore wind farms. Therefore, the corresponding electromagnetic transient simulations require large simulation times. This paper compares a detailed model of an off-shore wind farm with three clusters of 50 wind turbines each one (i.e. a total of 150 wind turbines), with a simplified model consisting of three aggregated wind farms. The paper includes the aggregation criteria so equal power flows and voltages are obtained at the wind farms points of common coupling. The control is carried out using a centralized PI controller to control total active power, and a distributed droop control for active and reactive power control of each wind turbine. The proposed aggregation method leads to significant savings on computational times, with the aggregated models being more than three hundred and fifty times faster than the detailed ones. The results have been validated by means of detailed PSCAD/EMTDC simulations.