Assessment of transmission network development with HV operation islands under renewable diffusion

The large increase of renewable distributed generation envisaged in the next future is yielding multiple concerns to the Transmission System Operators (TSOs). In particular, the connection requests to the EHV - HV network have to be appropriately included in planning studies, considering a rate of concretization of renewable generation initiatives and RES penetration targets in order to account for energy policies. Furthermore, the progressive decommissioning of thermal power plants in the medium/long term introduces additional complexities for both network planning and operation. In this paper, a real case study of the Italian power system is analyzed in the presence of HV operation islands (open loops at double-busbar substations) in static regime during critical contingencies, in a future energy scenario. The identified network reinforcements allow to alleviate the overloads and to improve the system performances.