High frequency characterization of the semi-conducting screens of medium voltage XLPE cables

In this study, a high frequency measurement technique to characterize the semi-conducting materials of the medium voltage XLPE cables in the frequency range of 30 kHz to 500 MHz has been developed. The influence of the experimental set-up and the sample preparation methods are investigated. A dielectric response model is then developed for the semiconducting materials and this is incorporated into a model for the whole cable. The propagation characteristics obtained from the cable model are then compared with those obtained from measurements carried out on the actual XLPE cables.