Providing Inertial Support from Wind Turbines by Adjusting Phase-Locked Loop Response

This paper focuses on mitigating the impact of reduced inertia of the power system due to high penetration of wind turbines. The study renews the understanding of phase-locked loop (PLL) and control system of wind turbine generator (WTG). A novel method to provide inertial support and synchronizing torque inherently is proposed by reducing the response speed of PLL without any supplementary control. The method can be used in any PLL-based control system. Doubly fed induction generator (DFIG)-based wind turbines are taken as an example. Similarities and differences between DFIG-based wind turbines with the proposed control method and traditional synchronous generator (SG) are pointed out. Time domain simulations on a modified 3-machines 9-nodes system validate the effectiveness of the presented control scheme.