Detection, localization and interpretation of partial discharge in the underground distribution network at Hydro-Québec

Most of power failures occur at cable joints in Hydro-Québec underground conduit network. Some are due to partial discharges inside these joints and the corresponding degradation of their electrical insulation. Hydro-Québec Distribution conduit network consist mainly of XLPE cable with rubber premoulded accessories. In 2001, Hydro-Québec started a research project for the diagnosis of underground cable and their accessories. This project was implemented for safety issues, to perform predictive maintenance and to withdraw defective accessories before failure.