Research on Signal Attenuation of High-Voltage Cable Insulation Sheath Detection Based on Traveling Wave Reflectometry

With the rapid development of the power industry, high-voltage cables play a vital role in power transmission, and the integrity of their insulation sheath directly affects the safety and stability of the power system. However, the aging of the sheath material and environmental factors can cause it to be damaged, which in turn can lead to serious power failures. Traditional detection methods have limitations such as complicated operation. Therefore, based on the principle of traveling wave reflectometry and a detection model of high-voltage cable sheath, this paper proposes a calculation model of shunt capacitance, which is used to study and calculate the attenuation effect of signals affected by cable length and minimum spacing of cable sheath in the detection process. MATLAB simulations were used to simulate the behavior of the reflected signal of the cable at different cable lengths and minimum spacing of cable sheath. The results show that in the simulation experiment with a cable length of 150m, the amplitude of the signal is attenuated from 10V to 1.72V after refraction and reflection, and the positive attenuation ratio of the signal transmitted from the head to the end reaches 2.41. With the increase of the cable length and the decrease of the minimum spacing of cable sheath, the amplitude of the reflected signal decreases significantly, and the positive attenuation ratio increases.