The study on diagnostics for aging trend of cable termination

The commercial diagnostics of insulation materials of cable system are the measurements of insulation resistance, dielectric power factor, and partial discharge. However, there is no standard stating permissible levels for these measurements. Besides, because the material breakdown may result from material aging or defect aging, the aging trends of different causes may be different. Therefore, two types of defects in cable terminations are made to comparing with good cable terminations. And two accelerating aging tests of cable system are set up in this paper. One is a synergistic experiment of temperature and moisture. Another environment is in a constant AC voltage of 15 kV_rms with a 300 A_rms current switching regularly. The measurements of partial discharge, insulation resistance, and dielectric power factor are all made periodically. The results show that dielectric dissipate factor has the ability to assess the aging degree of insulation of cable termination, and partial discharge measurement has the ability to detect defects in cable system but canpsilat assess the aging degree of insulation system. The insulation resistance measurement is improper to assess the aging degree of insulation system.