Insulation State Evaluation of High Voltage Cable Based on Conductor Potential Attenuation Method

The potential attenuation test of high-voltage cables is a testing method derived from the surface potential attenuation method of sheet-like samples and the polarization depolarization current method to characterize internal defects of cables. Using low voltage contact charging, and based on the obtained potential attenuation curve, characteristic parameters such as attenuation rate and initial potential are obtained to analyze the defect situation of different cable insulation layers. A testing platform for potential attenuation characteristics of high-voltage cable conductors was established in this paper, and the influence of testing distance, applied voltage, discharge resistance, and other factors on the insulation evaluation test of sample cables were analyzed. Based on the capacitance composition of high-voltage cables, an analysis system with three time constants was obtained, and the insulation state aging factor of high-voltage cables was proposed. Field measurements were conducted on a 110 kV highvoltage cable line, and the results were good.