Equivalent single-layer power cable sheath for transient modeling of double-layer sheaths

In this paper a model for cables with a double earth screen layer consisting of unequal conducting materials is developed. The earth screen is modeled by a single-layer with properties such that the transient behavior of the actual cable is reproduced. The first approach aims to equate the impedances and admittances of both models by varying parameters of the single-layer sheath model to optimize the match with the double-layer cable sheath. In the second approach the differences between the ABCD matrices of both models are minimized. By analyzing the ABCD matrices a method is developed to obtain a close match for transient behavior between single- and double-layer models. Analysis of the accuracy of the results shows a good match for the investigated cable.