Hierarchical control for hybrid wind systems

Hybrid wind systems couple wind turbines with storage and/or other generation technologies to maximize wind energy production while meeting operational requirements in terms of frequency control, regulation, load following, and scheduling. To increase fuel savings and emission reductions, a hierarchical control structure is proposed in this paper that combines supervisory control and component local control. In supervisory control, unit commitment and power dispatch are optimized and communicated to component local controllers. Frequency/voltage droop (P/Q droop) functions are developed for battery banks and diesel units to regulate system frequency and voltage. PSCAD simulation results indicate that the proposed hierarchical control strategy enables high wind penetration without compromising system performance.