Dielectric loss and partial discharge test analysis of 10 kV XLPE cable

With the advance of Chinese urbanization, cables are gradually replacing overhead lines and have been widely used in urban power system. With the growth of cables´ running time, however, the faults caused by cable aging are also increasing and thus how to evaluate the running status of the cable is becoming a problem increasingly concerned by urban power supply enterprises. To this end, the cable´s heating cycle voltage test platform has been designed and several XLPE cables containing intermediate connector and terminal connector are selected as samples to study the variation of operating status of XLPE cable referring to insulation resistance, dielectric loss tangent, partial discharge and some other electrical parameters that reflect the characteristics of cable running status in integral process of operation. Based on the platform, we control current, voltage to age the cable immersed in underground water, and also utilize dielectric loss measuring instrument and online partial discharge detection system to measure dielectric loss tangent and partial discharge of different time periods throughout the aging process. According to these electrical parameters, we obtain curves of cable running status that reflect the cable´s electrical condition in different period of running process. Finally, we synthesize the electrical parameters stated above, and preliminarily provide a strategy to evaluate the running status of 10kV XLPE cable.