On frequency regulation control strategy of wind turbine based on disturbance adaptiveness

Abstract

To solve the frequency problem caused by high wind power penetration, control strategies such as rapid power compensation (RPC) have been adopted to release the frequency regulation capability of new energy sources quickly. However, when the wind turbine (WT) adopts the RPC strategy to participate in the system frequency regulation, it cannot adapt to the random disturbance. In this paper, a disturbance adaptive RPC (ARPC) strategy is proposed. When the system is disturbed, the signal excitation method is used to estimate the external disturbance. According to the estimated disturbance, the WT rotational inertia is quickly used to compensate for the grid's unbalanced power. When the system frequency deviation and the rate of change of frequency (RoCoF) evaluation indexes meet the threshold requirements, the control strategy switches from ARPC to droop control, which can ensure the WT exit frequency regulation smoothly, and further reduce the frequency deviation and improve the frequency quality. Finally, analyzing the operation mode and determining the relevant switching logic, the proposed ARPC strategy's detailed implementation is developed. Simulation results proved the effectiveness and advancement of the ARPC based strategy.