OPERATIONAL EXPERIENCE OF THE WORLD’S FIRST TRANSMISSION LEVEL VOLTAGE HTS POWER CABLE

Underground High Temperature Superconductor (HTS) power cables have attracted extensive interest in recent years due to their potential for high power density. With funding support from the United States Department of Energy (DOE), the world's first transmission voltage level HTS power cable has been designed, fabricated and permanently installed in Long Island Power Authority (LIPA) grid. The HTS cable was successfully commissioned on April 22, 2008 and has been in operation since then. The three phase cable is 600 meter long and was designed to carry 574 MVA at a voltage of 138 kV. The project is being led by American Superconductor (AMSC). The team is comprised of Nexans, Air Liquide and LIPA. This paper describes the operational experience of the cable and refrigeration system since energization. A detailed description of various events and lessons learned over the course of operation is presented. The cable system performance is compared before and after more than one year of in-grid operation. In addition, the status and progress of the recently awarded LIPA II project is included.