Characterization of laboratory aged MV XLPE cables using dielectric losses factor measurements

This paper analyses characterization results of Dielectric losses factor experiments performed on laboratory-aged and non-aged 18/30 kV XLPE insulated Medium Voltage (MV) cable samples. Dielectric losses factor was used to characterize and assess, according to IEEE and IEC standards, the state of the investigated cables insulation under electrical and thermal accelerated aging. For this purpose, full size of MV 18/30 (36) kV XLPE cable samples were aged under electrical stress at three levels of voltage (18 kV, 36 kV and 54 kV) during 2000 hours. Under thermal aging conditions, continuous and load cycling tests were carried out at four different temperatures ranging from 80°C to 140°C during 2000 hours and 20 thermal cycles of 8 hours current on and 16 hours current off, respectively. Results showing the evolution of the dissipation factor and the dielectric losses power versus electrical stress are presented and discussed.