Analysis and Control Parameters Optimization of Wind Turbines Participating in Power System Primary Frequency Regulation with the Consideration of Secondary Frequency Drop

With the increasing integration of wind energy into power systems, maintaining frequency stability has become a significant challenge. To address the issue of secondary frequency drop caused by wind turbines exiting the primary frequency regulation of power systems, this paper presents a control parameters optimization method of wind turbines participating in power system primary frequency regulation. Initially, with the assumption of constant wind speed and linearization of the wind power coefficient, the relationship between the mechanical power and rotor speed of the wind turbines is established. Subsequently, the primary frequency regulation component of wind turbines is integrated into the classical system frequency response (SFR) model, accounting for the effects of exiting time and rotor speed variations. Following this, the dynamic frequency of the power system is computed with the modified SFR model, and the time domain expressions for both primary and secondary frequency drops are derived. Furthermore, an optimization model for the control parameters of wind turbines participating in primary frequency regulation is developed, aiming to minimize the values both of primary and secondary frequency drops. Finally, a case study is constructed to validate the efficacy of the proposed method. The results demonstrate that the optimization method introduced in this paper significantly enhances the dynamic characteristics of the system frequency.