The Influence of Mechanical Pressure on Solid/Solid Interface Under DC Voltages

The increased penetration of renewable energy sources in power systems is leading to an extensive use of HVDC cable systems. The weak points of cable systems, HVDC or HVAC, are the accessories, and the solid/solid interfaces. In this paper, experiments conducted to investigate the electric characteristic (DC breakdown voltage, DC leakage current and DC partial discharge monitoring) of solid/solid interfaces are reported. Emphasis is given to the influence of the mating pressure. The results seem to indicate that mechanisms not related to partial discharges are not the root cause for breakdown.