Power Cable Joint Model: Based on Lumped Components and Cascaded Transmission Line Approach

Models in high frequency range for underground power cable connections are essential for the interpretation of partial discharge (PD) signals arising e.g. diagnostic techniques. This paper focuses on modeling of power cable joints. A lumped parameter odel and a cascaded transmission line model are proposed based on scattering parameters (S -parameters) measurement on a 10 kV oil-filled PILC-PILC straight cable joint in the frequency range of 300 kHz-800 MHz. It is shown that the lumped model is suitable for up to 10 MHz while the transmission line model can cover the whole frequency range. The cascaded transmission line model is applied to simulate the reflection on a 150 kV single core XLPE straight joint. Comparison between measurement and simulation indicates that the model parameters (characteristic impedance and propagation coefficient) can be matched to predict the joint’s propagation characteristics.