Verification test of 22.9kV underground HTS cable

Several verification tests are being underway world widely in order to apply HTS cable to real grid. KEPCO (Korea Electric Power Corporation) has initiated HTS cable project since 2002 with the aid of MOCIE (Ministry of Commerce, Industry and Energy), Korea. The HTS cable system with the specification of three-phase, 1.25 kArms, 22.9 kV and 100 m was installed at the KEPCO’s Gochang test yard. In consideration of economical efficiency on retrofit for typical underground cable, the HTS cable was designed to be applicable for 175 mm ELP duct and 55 m-long cable was laid on underground trench in the same manner as the conventional pulling method. Cool-down to LN2 temperature and warm-up to room temperature were performed several times to investigate the influence of thermal cycle. The main objectives of this project are to verify performance of the HTS cable system and evaluate the economical and technical feasibility from all angles. Expected pros and cons of HTS cable including reliability and maintainability will be assessed with the view point of utilities. This paper summarizes some results of installation and after-laying tests.