Stand-alone Hybrid Power Plant for Ancillary Services Provision

Changes in the generation mix will increase fluctuation of power balance in energy systems and simultaneously will decrease available resources of Ancillary services (AnS) to stabilize those fluctuations. Renewable resources (RES) are not primarily designed to provide AnS. Thus, alternative AnS resources has to be found or built to prevent a shortfall in available AnS capacities. An ideal AnS provider is independent on internal or external circumstances and provides services with high availability and reliability. Such requirements may fulfill a stand-alone hybrid powerplant designed as virtual power plant (VPP) only for AnS provision, comprised of battery energy storage system (BESS) and small spinning generators. The generators are stopped and ready to start when there is no significant demand for AnS, which challenges operation of the power plant: the service demand is unknown in term of activation time and required power, optimal scheduling of generator operation (up-time) is crucial both for cost efficiency and service provision quality. Robust control algorithm is introduced in this paper using rolling time window, demand interpreter, scheduling module and real time power adjustment module.