Power System Fault Recovery Considering Frequency Deviation Under Large-Scale Wind Power Access

[Objective] This study addresses the challenges posed by the increasing integration of high proportions of renewable energy on the safe and stable operation of power systems. The objective is to enhance reserve capacity during fault recovery process， thereby ensuring system frequency stability. A novel fault recovery model， incorporating frequency deviation under large-scale wind power integration， is proposed to optimize this process. [Methods] First， a power system frequency response model that incorporates large-scale wind power integration was developed. The frequency deviation was derived using the Laplace final value theorem， and power fluctuations were calculated. Second， to maximize the incorporation of generator regulation capacity， the minimum values of the power fluctuations， generator output boundary， and ramp rate were considered to determine the maximum adjustable reserve capacity of each unit. This ensures sufficient reserve capacity during fault recovery to address wind power fluctuations. Third， to address the multi-objective nonlinear nature of the fault recovery model， piecewise linearization and weighting methods were employed to solve the multi-objective function with load loss， generator operation cost， and reserve cost as the objectives. [Results] The model was validated using an IEEE 39-bus system. A comparison among conventional fault recovery （without considering frequency deviation）， reserve recovery （without considering frequency deviation）， and reserve recovery （considering frequency deviation） demonstrates that the proposed reserve recovery model enables more efficient reserve capacity allocation during fault recovery. Therefore， it ensures that the system frequency deviation remains within ± 0.2 Hz. Additionally， the model reduces system load loss by approximately 24.63% and the total cost by approximately 36.62% compared with traditional methods. [Conclusions] The proposed model significantly suppresses the frequency fluctuation before and after a fault， ensuring stable operation of the system frequency while achieving optimal economic benefits and reducing fault load loss.