Progress and Results of Type Test of 23 kV 60 MVA Class Concentric HTS Cable

Korea Power Electric Corporation (KEPCO) has established a general standard (GS) for a 23 kV AC three-phase concentric HTS cable system, based on international specifications such as IEC 63075 and CIGRE TB-538. Following this GS, we conducted a Type Test on a 100-meter-long HTS cable system rated at 23 kV and 2,120 A<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">peak</sub> under sub-cooled LN2 conditions. The test loop consisted of EB-G, Span #1, NJ, Span #2, and EB-A in series. Span #1 was made longer than Span #2 to enable more accurate AC and heat loss measurements, accounting for temperature sensor tolerance between EB-G and NJ. The Type Test included sequence and component tests. After the bending test, the cable was installed at KEPCO Power Training Center in Gochang, Korea, and later cut for component testing. Before cooling, a 10.5 barg pressure test was performed for 30 minutes, followed by five heat load cycles. Losses were measured at outlet temperatures above 76.15 K and inlet pressures below 5.33 barg, yielding 2.548 mbar/m at 0.458 kg/s and 3.74 W/m at 0.455 kg/s. Voltage and 20-cycle load tests at 26.4 kV were conducted, with partial discharge measured before and after. A final visual inspection was performed. System assembly is now underway in Munsan, Korea.