Aging Evaluation of 10kV overhead Cables Based on Frequency Domain Spectroscopy

With the extensive application of 10kV overhead insulated lines, grounding accidents caused by insulation degradation or damage seriously affect reliable operation of the distribution network. The insulation status of overhead insulated lines is comprehensive result of complicated operating conditions, such as thermal aging, damp oxidation and transient overvoltage damage. Thus degradation status assessment is of great significance to power supply safety. In this paper, frequency domain spectroscopy (FDS) method is applied to evaluate degradation status of various aging overhead insulated lines. Firstly, accelerated thermal aging samples in 80°C are prepared, and quantization parameters obtained are assessed corresponding to aging statues. As the aging time increases, the loss peaks appearing in the complex permittivity and complex capacitance gradually shifts to low frequencies, and the loss peaks finally decreases. The verification results show that FDS method is an effective and rapid access of degradation status assessment.