AC Loss Characteristics of Superconducting Power Transmission Cable
Characteristics of lOm-long Nb3Sn superconducting power transmission cables are described. Cables are designed to be suitable for power of 1 to 3 GW and are assembled using Nb3Sn superconducting tapes.
Ac losses, which are of major concern in superconducting cables, is greatly dependent on the design of the cable. And it is very important to assemble cables to avoid the influence of the thermal contraction. Several superconducting cables have been assembled and tested so far1). In this paper, two cables among them are picked up, then their ac losses and assembling method are discussed. One of them(cable“N”) is assembled by the following method: The electrical insulation of the cable is composed of many pieces of tyvek paper, each of which is helically wound with an appropriate lay angle to reduce axial thermal contraction.
Ac losses of this cable were reduced to about 1/5 to 1/10 of that of the other cable(cable“I”). To investigate the causes of the higher ac losses in cable“I”, it was disassembled after the ac loss measurement. Then some degraded NbgSn tapes with traces of edges of the insulator tapes and wires for measurement were found. In order to estimate the degradation of tapes, their critical currents are measured. There are some tapes whose critical currents reach less than half that the original tape.
KeywordsCritical Current Thermal Contraction Eddy Current Loss Corrugate Tube Conductor Tape
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- 1).Higuchi, N., Natori, N., Arai, K, and Hoshino, T., Nb3Sn superconducting power transmission cable. In Proc. of International Symposium on New developments in applied superconductivity, ed. Y. Murakami, World Scientific, Osaka, 1988, pp. 668–673.Google Scholar
- 4).Itoh, N., Natori, N. and Higuchi, N. “Superconducting power cables and their current tests”, Transactions of JIEE of Japan (B)., 1981, 101,443–450Google Scholar