Frequency Modulation Strategy of Wind Power Generation in Power System of High Renewable Penetration

Abstract

Wind turbines generally adopt the maximum wind energy tracking control strategy, which makes them obtain the best power generation efficiency. However, this makes wind turbines unable to respond to changes in system conditions, provide inertial support for the system, and participate in the primary frequency modulation of the system, which brings challenges to the frequency safety of high-proportion new energy power systems. In order to improve the frequency stability of high-proportion new energy power system and make wind turbines participate in frequency control actively, this paper proposes a primary frequency modulation control strategy based on load reduction for doubly-fed wind turbines. According to the aerodynamic characteristics of variable pitch wind turbine, a coordinated load shedding control strategy combining variable pitch and variable speed operation was proposed to make the wind turbine have active power reserve capacity. A frequency response link is added to the power control, so that the unit can output power to realize inertia and frequency support when the system frequency fluctuates. The simulation results show that the proposed control strategy can improve the system inertia and primary frequency modulation capability in the full wind speed operating domain under the load mutation condition, and improve the frequency stability of the system after the wind turbine is connected to the grid.