Closed-Form Solution of Three-Generator System Frequency Response Model Considering Wind Power

The integration of wind power into the grid exacerbates the uneven inertia distribution between different regions, which brings challenges to the post-fault frequency response (FR) solution of the large-scale power system. The three-generator system frequency response model considering wind power (TGSFR-W model), based on the DC power flow network and combined inertia and drop control strategy for wind power output, is first proposed in this paper to preserve the frequency spatial distribution characteristics (FSDC). Then, the mathematical equation of the TGSFR-W model is simplified to the forced vibration equation for a three-degree-of-freedom damped system. Finally, the closed-form solution (CFS) of TGSFR-W model is derived based on the well-established theories in vibration mechanics. Case studies verify the validity of the TGSFR-W CFS and carry out a parameter sensitivity analysis to assess the impact of wind power participation in FR on frequency stability. Simulation results show that the proposed method can deduce the post-fault FR evolution with high speed, which can be applied to the frequency stability online analysis.