Application of Prediction Intervals to Probabilistic Reliability Evaluation of Unit Commitment Based on Day-ahead Forecast of PV Power Output

The prediction interval (PI) in forecast of photovoltaic (PV) power corresponds to the range of feasible PV power output at a specific confidence level. Although several studies have addressed unit commitment (UC) based on PIs of PV power, in future power systems with extremely largescale PV integration, it is difficult to determine UC for supplying electricity from the PI lower to upper bounds, and the power system operator must properly estimate the supply- demand imbalance after determining the UC. In this paper, we propose a probabilistic reliability evaluation of the day-ahead UC. The proposed method probabilistically determines the supply-demand imbalance due to forecasting error using PIs and evaluates the imbalance trend and value throughout the day.