Advanced Control of a DFIG-based Wind Power Plant for Frequency Regulation

The expansion of renewable power penetration in the power system has given rise to many concerns in terms of frequency stability. Since unlike the conventional synchronous generators, these intermittent energy sources do not inherently undertake frequency regulation. For instance, The Doubly-fed induction generator (DFIG) based wind power plants have a destitute response to frequency deviations, being that its rotational speed is almost totally disassociated from the grid frequency. Another point is that significant wind power penetration leads to the retirement of many conventional power plant. Which lowers the power system's total inertia and the power reserves that are normally needed to preserve the frequency within an adequate range of variation. Therefore, this paper proposes an advanced control strategy that allows of the DFIG based wind energy conversion system to provide, at the event of frequency excursion, an inertial support for the power system through a simultaneous use of the kinetic energy reserved in the turbine rotating masses and a portion of the energy reserved in the DC-link capacitor. A case of four synchronous generators SGs connected with a DFIG bases wind farm WF considering a sudden frequency disturbance has been studied using Matlab/Simulink to validate the capability of the suggested control strategy.