In this paper, the authors present a comprehensive electro- thermal circuit model along with an experimental setup to determine the maximum power transfer capability of a HVDC power cable. The non-linear conductivity of XLPE is experimentally measured and then incorporated in the circuit simulation model. The maximum thermal voltage (MTV) of the cable is computed under different load currents and ambient temperatures. An experimental setup to conduct breakdown tests on loaded HVDC cables is presented. Breakdown tests are conducted on the cables of the same rating as used for simulation, under similar variations in load current. The breakdown voltage-load current elliptical characteristics, which signifies the maximum power transfer capability of the cable, are obtained both through simulation as well as experiments. The coefficients of the elliptical characteristics are obtained. The results are found to be in close conformity. The results are considered useful for the HVDC cable utilities and manufacturers.
Breakdown, HVDC, XLPE, Power cable, Electro-Thermal, MTV, Load current.