Coordinating control for a wind-hydro-storage system considering the constraint of SOC

In order to effectively utilize wind, water and other renewable energy, a wind-hydro-storage system is proposed in this paper to smooth the power fluctuations of Point of Common Coupling (PCC). The topology and control objective of the system are firstly presented and the control models of hydro and storage units are then described by means of classic transfer functions. Further, coordinating control strategy of the system is discussed in detail to allocate power reasonably through a power distributor and an output limit coordinator. Considering the negative effect of State of Charge (SOC) limit exceeding in storage unit, a power corrector based on fuzzy control method is adopted to ensure safe and stable operation of storage unit and improve smoothing effect of the system. The effectiveness of proposed control strategy is verified by case study in MATLAB/SIMULINK.