Security-Constrained Redispatching to Enhance Power System Resilience in Case of Wet Snow Events

Natural threats may cause multiple dependent contingencies on a power system (PS), leading to partial or total load disconnection. Given the high social and economic costs of such disruptions, the Transmission System Operators (TSOs) are interested not only in predicting these potential critical scenarios, but also in applying suitable preventive and/or corrective countermeasures to increase the system resilience. In case of wet snow storms one interesting countermeasure consists in increasing the line current to avoid the formation of an ice sleeve on the conductors. This paper proposes a Security-Constrained Redispatching (SC-R) run on hourly basis during the whole forecasted duration of the wet snow event and aimed to assure, in addition to N −1 security, a minimum current on the most exposed lines thus preventing ice sleeve formation. Simulations performed on a realistic wet snow event in the Italian EHV grid confirm the effectiveness of the proposed approach under specific weather conditions.