The insulation properties of cryogenic liquid impregnated tapes

The partial discharge properties of the cable model insulated with the cryogenic liquid impregnated tape were studied. As we confirmed that the breakdown strength of the paper-like single sheet sample in liquid was dependent on the permittivity ratio of liquid to fiber, the partial discharge inception stress in the butt gap of the cable was analysed using the permittivity ratio of the liquid to the insulation tape. The results showed that the discharge in butt gap was triggered by the surface discharge along the boundary between tape and liquid in the butt gap, and that it was hard to propagate hydrostatic pressure into the butt gaps of the cable lapped with the film such as PE film.