A Coordinated Fuzzy-based Frequency Control Strategy of Wind-storage System

With the increasing integration capacity of largescale renewable energy, its intermittent and fluctuating generation features are disintegrating the frequency stability of power grid. Although wind turbines can be dispatched in frequency regulation process through its de-loaded reserve or rotation kinetic energy, however, the wind speed in actual scenarios is stochastic, and the frequency regulation ability of wind turbine is instable. Therefore, considering the outstanding order-tracking and power-response features of energy storage system, a flexible operation mechanism and collaborative control framework for the wind-storge system to participate in frequency regulation is proposed in this paper. Firstly, taking the operation states of wind-storage system and the frequency characteristics as the inputs, the regulation coefficients of wind-storage system are dynamically determined by the fuzzy controller designed in this paper. Then, under the proposed coordinated operation strategy, the combined system can fulfill the frequency regulation demand in a wide range of wind speed. Finally, the effectiveness of control strategy is verified through simulation, and the results demonstrate that the proposed control strategy can enhance the frequency regulation potential of wind turbine through limited energy storage capacity.