Recent Progress in the Development of YBCO HTS Power Cables

Abstract

There are expectations for high-temperature superconducting (HTS) power cables as a compact cable with large capacity and low-loss power transmission. Recently, the stable manufacture of many long REBCO (RE = rare-earth element) tapes has been achieved. REBCO tapes have a high critical-current density, and the AC loss resulting from the parallel magnetic field is extremely small because of the thin-film structure of the superconducting layer. The basis of the M-PACC (Materials & Power Applications of Coated Conductors) project is to develop a process technology for fabricating REBCO tapes and promote development aiming toward the commercialization of superconducting cables using REBCO tapes. Two types of HTS cables are being developing as part of this project. These cables have superior transmission efficiency, lower loss and larger capacity than existing power cables. One is a 66 kV/5 kA three-core large-current cable and the other is a 275 kV/3 kA single-core high-voltage cable. There are several development targets. We examined factors such as AC loss, thermal characteristics of the cables under over-current and the optimum cable design. This paper provides an overview of the project and describes its progress.