Electrical and cryogenic tests of the 1200 m HTS DC cable system

Comprehensive tests of all the components of the HTS DC line were carried out as a part of the project to create a superconducting cable line with a capacity of 50 MW for the power system of St. Petersburg. HTS DC cable line will connect two substations of different voltage in the center of the city. The experimental stand included several cable lengths with joints and current leads, a reverse cryostat, a two-circuit cryogenic system with a capacity of 12 kW at 77K, a converter station and a control and monitoring system. The total length of the cryogenic line exceeded 1200 meters. The report presents the results of vacuum, cryogenic and electrical tests carried out over several months. The electrical and hydraulic characteristics of the HTS cable line were determined. Some emergency modes of the cryogenic system were studied. The possible time of cable operation in various accidents in the cryogenic system was estimated.