Flexibility and Operating Reserves in Electric Power Systems

Maintaining the efficiency of electric power systems (EPSs) requires some flexibility margin, which decreases in the case of adopting a variety of renewable energy sources (RESs). For this reason, the determination of the EPS flexibility several hours ahead becomes especially urgent. In this study, the flexibility of a 5-node EPS with a four-minute load change during a 6-hour time horizon is calculated. To this end, a probabilistic method based on the analysis of the cumulative probability of the available flexibility is used