The 345-kV underground/underwater Long Island Sound cable project

A high-voltage underground/underwater cable system was installed to increase the transmission capacity from the mainland of New York to Long Island. The use of high-pressure fluid-filled (HPFF) pipe-type cable on the land portion represents the largest application of paper-propylene-paper (PPP) insulated cable in the United States. State-of-the-art technologies were implemented in the use of fiber optic cables for relay protection, temperature monitoring and leak detection systems, SF/sub 6/ gas-insulated substations, and underwater cable laying and embedment techniques. The design and installation of a 750 MVA, 43 km (26.6 miles), 345 kV underground/underwater electric transmission system are discussed.<
>