Direct Introduction of Semicon Layers in a Cable Model


Department of Electrical Engineering,Sharif University of Technology


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
signi cant e ects on PD signal attenuation and its propagation velocity. There is a substantial
need for improvements in the
exibility 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.