Frequency Trajectory Planning-based Frequency Regulation Strategy for Wind Turbines Equipped with Energy Storage System

The increase in wind power penetration has weakened the equivalent inertia of the power system, posing a significant challenge to frequency stability. In this paper, a frequency trajectory planning (FTP)-based frequency regulation (FR) strategy is proposed for permanent magnet synchronous generator-based wind turbines equipped with an energy storage system (ESS) on the DC link. The core idea is that the frequency index provided by the grid code is used to plan a safe frequency trajectory when the system frequency fluctuates. The FR power provided by the ESS is controlled by tracking the planned frequency trajectory to compensate for the unbalanced power in the system, provide inertia support, and ensure the frequency stability of the power grid. The proposed strategy can suppress the frequency fluctuation and optimize the FR power of the ESS. It also effectively circumvents the complex parameter design process of virtual inertia control. The simulation model is established in Matlab/Simulink to verify the effectiveness of the control strategy.