Development of 500 KV DC Self-Contained Oil-Filled Cable

This paper gives some observations on the insulation properties and on the type test method of ±500kV self-contained oil-filled(OF) dc cable including some accessories. The cable and accessories were subjected to a withstand test at the factory laboratory, to a type test recommended by CIGRE SC-21 for dc cable (abbreviated as CIGRE Type Test) for a short sample and to a long-run test on a long cable sample at Takeyama Cable Testing Station. At the first step some cables experienced breakdown, however, at the final stage all cables successfully withstood the above tests and also the more severe supplementary tests.