Application of virtual energy storage to partially mitigate unscheduled interchange caused by wind power

Each balance authority (BA) in a grid conforms to a schedule that sets forth how much capacity will be allowed to pass through the area at given times of the day. However, because wind generation is variable and non-dispatchable source of energy, it causes additional unscheduled deviation of interchange and complicates the problem of system balancing. Thus, BAs need to procure more fast regulation capacity to meet Control Performance Standards (CPS) requirements. A fast-response storage device with appropriate duration is more effective than conventional generation for regulation service. However, depending on technologies, capital costs of energy storages are very high. As such, in this paper, a novel concept of virtual energy storage is proposed to respond to a filtered area control error (ACE) signal. This will bring about benefits include less amount of regulation that can be procured (lower regulation service cost), and decreased area control errors. The simulations performed on the Northwestern power grid demonstrated the effectiveness and efficiency of this method.