Direct Introduction of Semicon Layers in a Cable Model

The detection and location of any partial discharge (pd) signal requires an accurate frequency dependent cable model to correctly simulate the pd signal attenuation during its propagation in the cable. this model should be capable of simulating the semiconducting layers, which have significant effects on pd signal attenuation and its propagation velocity. there is a substantial need for improvements in the flexibility of the transient cable model through direct introduction of the two semiconducting layers in the cable model. this can be employed in the next step to develop a 3-phase cable model for atp. this paper has derived an impedance formula for the semiconducting layers. the propagation characteristics of the pd signal, in a cable having two semiconducting layers, are evaluated by applying the derived formula and are compared with the related characteristics in a cable with no semiconducting layer. the propagation of a pd signal applied to the sending end of the core conductor is investigated. in the application of the semicon pick-up sensor in the cable joint, there would be a considerable high frequency voltage across each semiconducting layer, which can be used for the study of pd phenomenon.