Partial discharge measurements in a high temperature superconducting triaxial 5-m model cable at liquid nitrogen temperature

A prototype 5-m triaxial high temperature superconducting (HTS) distribution class cable using a cold dielectric design was tested at high voltage under various conditions including AC, impulse and partial discharge (PD). The dielectric consists of wrapped synthetic tape insulation with liquid nitrogen filling the butt-gaps. In this paper we report on the partial discharge signals in the cable and methods for data analysis. All measurements were made cold in liquid nitrogen. The data will be presented in terms of PD amplitude and energy. Partial discharge signals were observed in the presence of large amounts of background noise due to the inverter circuits of the cryogenic system and these issues will also be discussed.