Superconducting energy pipelines (SEPs) which can simultaneously transmit liquefied natural gas (LNG) and electricity over long distances are proposed these years. SEPs combining LNG pipelines and high-temperature superconducting (HTS) cables together have higher transmission efficiency. The stable and reliable operation of SEPs during short-circuit faults is important. The HTS cable generating heat may cause the liquid protective medium (LPM) inside the copper former of the cable to boil, endangering the safety of SEP during short-circuit faults. The objective of this paper is to obtain the influence of short-circuit faults on the temperature of HTS cables in SEPs. Three different structures of copper former in HTS cables of a ±100 kV/1 kA SEP are investigated including copper rod and two different copper tubes. One inside of the copper tube is vacuum calling internal vacuum copper tube (IVCT) and the other one is LPM calling internal LPM copper tube (ILCT). Simulation results show that the ILCT has the best properties due to its lowest temperature during short-circuit faults. When a fault current of 20 kA transports in the HTS cable for 100 ms, the cross-sectional area of the copper former should be larger than 187.46 mm2 to ensure safety.

中文翻译：

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超导直流输电管道高温超导电缆短路故障时的温度分析


近年来，人们提出了可以同时长距离传输液化天然气（LNG）和电力的超导能源管道（SEP）。将液化天然气管道和高温超导（HTS）电缆结合在一起的SEP具有更高的传输效率。短路故障期间SEP的稳定可靠运行非常重要。高温超导电缆发热可能导致电缆铜管内的液体保护介质（LPM）沸腾，发生短路故障时危及SEP的安全。本文的目的是获得短路故障对 SEP 中高温超导电缆温度的影响。研究了 ±100 kV/1 kA SEP 高温超导电缆中三种不同结构的铜管，包括铜棒和两种不同的铜管。铜管的一根内部为真空，称内部真空铜管（IVCT），另一根为LPM，称内部LPM铜管（ILCT）。仿真结果表明，ILCT在短路故障时温度最低，因此具有最佳性能。当20kA的故障电流在高温超导电缆中传输100ms时，铜骨架的截面积应大于187.46mm2以保证安全。