Construction of a 500-kV DC PPLP-insulated oil-filled submarine cable

摘要

Construction of a 500-kV DC PPLP-Insulated Oil-Filled Submarine Cable - by Toshiyuki Inoue, Yuichi Maekawa, Hiroshi Suzuki, Kouhei Furukawa, Ryosuke Hata, Kaihei Murakami, Munehisa Mitani, Hiroyuki Kimura, Hirofumi Hirota, Yoshihisa Asao, YuichiAshibe and Morihiro Seki - This report describes the construction of a 500-kV DC PPLP-insulated oil-filled submarine cable linking Japan's Kansai and Shikoku regions. The world's first application of PPLP to DC cables enabled a±500-kV single bipolesystem to transmit bulk power up to 2800 MW. The reliability of PPLP as a DC insulation material was verified by several fundamental tests followed by a long-term accelerated aging test of prototype cables and accessories. Because of the considerablelength of the cable, the pumping plant system was adopted as an oil-feeding system for the submarine cable section and the reliability of the cable system was enhanced by incorporating optical fiber sensors into the submarine cable. To realize high-speedsimultaneous laying and embedding, a plough-type cable-embedding machine with a water jet was developed. A burial depth measurement system was also developed, which can detect both the location and the burial depth of the submarine cable by the ACmagnetic sensor system.