Contribution of DFIG-based wind farms to power system short-term frequency regulation

A control strategy that provides a doubly-fed Induction generator (DFIG)-based wind farm with the capability to provide short-term frequency regulation is investigated. The controller manipulates dynamically the position of the DFIG rotor flux vector to slow down the generator allowing for a temporary surge in the power output, which helps to reduce the frequency drop following the transient period after the loss of network generation. A generic network that combines synchronous and wind-farm generation has been modelled and used for control system design and dynamic assessment. Studies are conducted for the DFIG operating at different speed and power output conditions. Simulation results are described which illustrate the contributions to frequency support of DFIG-based wind farms controlled with the proposed strategy. Machine data and control parameters are provided.