Study on the effect of inner discharge on temperature distribution in power cable terminal

Partial discharge due to inner defects in insulation system may produce many kinds of physical effects leading to insulation degradation and breakdown, one of which is thermal effect. The thermal effect of inner discharge in solid insulation system, such as power cable terminal, is investigated in our group. In this paper, a relationship between the energy of inner discharge and temperature distribution is presented based on the theory of heat-transfer, and some typical computed thermograms for the power cable terminal with different discharge energy are also given, which are consistent with the measured infrared thermal graph. Finally, the diagnoses of power cable terminal based on the thermal effect of inner discharge are discussed.