Characteristics of Mechanically Damaged Single-Core Oil-Filled Cable

Underground power transmission lines of 60 kV and over now in use in Japan are mostly oil-filled (OF) cables. In particular, the use of 140-kV OF cable has been sharply increasing of late. The cable is liable to various kinds of mechanical damage (excluding mechanical fatigue phenomena), some of which are considered to affect adversely its performance. Therefore, by subjecting a 140-kV single-core OF cable, as a representative cable, to various kinds of mechanical damage, the kinds and degree of damage done was studied and experiments made to ascertain the relationship between possible damage to the cable and its electrical properties.