The restoration field tests in Sardinian network involving HVDC, synchronous condensers and hydraulic power plant

This paper describes the studies performed by Italian TSO Terna, together with CESI, about feasibility of power system restoration strategies including HVDC links. The recent European Regulations ask for the design and implementation of proper restoration plans, considering all the generation, load capabilities and network characteristics. In the Italian power system, Sardinian network relies on several restoration paths. Indeed, the island is also connected to Italian peninsula through two HVDCs, SA.PE.I and SA.CO.I, the last of which is also a multi-terminal link connecting French island of Corsica. In light of this scenario, the paper firstly presents the outcomes of the preparatory investigations and later provides the results of five major restoration tests, performed between 2015 and 2017. Future trends in a context of continuous restoration plan update are also provided.