Study on Propagation Characteristics of High Frequency Signal in Medium Voltage XLPE Cable Joints

In this paper, propagation characteristics of the 8.7/10kV XLPE cable with joints are investigated by using the CST software. Establishing multiple cable joints model based on finite integral method, it focuses on the relationship between attenuation constant and phase velocity. The simulation results show that the phase velocity is violently shaken with the huge change of attenuation constant in low frequency. It is worth mentioning that in the frequency range from OGHz to 1GHz, there are two frequency bands with little change of phase velocity, which are range from 250MHz to 350MHz and from 650MHz to 850MHz. Since the attenuation constant is not large in the low frequency range from 250MHz to 350MHz, the Signal-to-Noise Ratio is high. It will be helpful to improve the accuracy of partial discharge detection if selecting the signal in this frequency range.