Research on Coordinated Frequency Regulation Control of Wind Turbines

Abstract

Variable speed wind turbines (WTs) are linked to the grid via inverters, so the rotor cannot provide inertial support for grid frequency fluctuation. In recent years, the proportion of wind power is increasing, which seriously threatens the frequency stability of power system. In this paper, two traditional inertial control methods are researched. Based on this research, the variable coefficient integrated inertial (VCII) control method is proposed, which enables the output power of WT based on permanent magnet synchronous generator (PMSG) to be changed on the basis of the degree of frequency change. On this basis, a coordinated frequency regulation control strategy with VCII control combined with pitch angle control is proposed. By adopting different control methods for different wind speeds, the WT can participate in grid frequency regulation more targeted. At last, the simulation shows that the coordinated frequency regulation control method can fully stimulate the frequency regulation ability of WT.