Scheduled operation of wind farm with a battery-energy-storage system considering ramp events

Renewable energy such as wind generation is a countermeasure against global warming and fossil-energy resource depletion. However, wind-farm (WF) output fluctuates because of unstable wind conditions and the occurrence of long-term fluctuations, which are called ramp events. WF power generation operator needs to observe the grid code (GC) by controlling wind generators themselves or adjusting a WF output with the energy-storage system (ESS). Accordingly, scheduling the operation of WF with ESS and WF output forecast is necessary. Scheduled operation has two parts: scheduling of generation plans (SGP) and operating WF (OWF) outputs with the charge/discharge of ESS. This paper proposes the scheduling method, which can control ramp events and satisfy GC formulation such as mixed integer liner programming in the SGP part, and the balancing method, which can reduce the imbalance energy due to control delay of ESS in the OWF part. We also evaluate these methods by annual numerical simulation. We further confirm the validity and effectiveness of the proposed method, as well as approximate its battery capacity requirement