Cable Degradation Positioning Algorithm Based on Broadband Impedance Spectrum

Power cable is widely used in urban distribution network. Under long-term operation, there will be insulation degradation in these cables, which will affect the safety of the power system. In this work, an algorithm based on broadband impedance spectroscopy (BIS) is proposed. The inhomogeneous conductivity and capacitance defects in cable are accurately positioned by windowing of frequency domain function and incident Gaussian function signal. From the simulation results, it can be found that BIS is more sensitive to the change of equivalent capacitance. When the capacitance increases, the positioning spectrum presents a negative first and then positive reflection peak. When the capacitance decreases, it presents a negative peak first and then a positive peak. The value of reflection peak increases with the capacitance variation.