International Journal of Recent Technology and Engineering (IJRTE) ISSN: 2277-3878, Volume-8 Issue-4, November 2019 5279 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: D7452118419/2019©BEIESP DOI:10.35940/ijrte.D7452.118419 Abstract: Detection and understanding of different high frequency phenomenon in multilayered underground (UG) cable require a thorough study of wave propagation mechanism which is governed by the line parameters of the cable. Line parameters are the functions of cable geometric and electromagnetic properties. Therefore the inclusion of semiconducting screen in cable structure influences the line parameters as well as wave properties of the cable. This paper aims to investigate the effects of the variation of different geometric and electrical properties of the semiconducting screen on line parameters as well as wave propagation characteristics of UG cable over a wide range of frequency. The complete impedance matrix of cable considering the effect of the semiconducting screen is derived using loop current analysis without invoking the theory of a double-layered conductor system. A comparative analysis on the effect of parametric variations of the semiconducting screen on line parameters as well as wave properties between the cable with and without semiconducting screen over a wide range of frequency is performed. This analysis indicates that the wave properties like attenuation or phase velocity are considerably influenced by inclusions of the semiconducting screen in cable structure, especially at high frequency. Keywords : Loop Current, Mesh and phase domain, Skin Depth, Attenuation Constant. I. INTRODUCTION Like transmission line, underground (UG) power cable is also susceptible to different high frequency phenomenon which propagates as a wave through it. As the wave propagation mechanism in a cable is governed by its primary line parameters, cable geometry and material properties have a direct influence on its wave properties. Therefore the inclusion of semiconducting screen in cable structure has a considerable effect on primary line parameters which in turn influences the wave properties of the cable. Determination of wave properties of UG cable based on cable primary line parameters requires the derivation of a complete model of impedance and admittance of the multilayered cable which was first successfully done in [1] based on the electromagnetic analysis of coaxial cylinder [2]. Though this model has widespread applications in the study of high frequency behavior of multilayered cable [3-6], it is only suitable for cable structure containing alternate conducting Revised Manuscript Received on November 15, 2019. * Correspondence Author Swarnankur Ghosh*, Department of Electrical Engineering, National Institute of Technology Meghalaya, Laitumkhrah, Shillong, India. Email: swarnankur.ghosh@nitm.ac.in Supriyo Das, Department of Electrical Engineering, National Institute of Technology Meghalaya, Laitumkhrah, Shillong, India. Email: supriyo@nitm.ac.in and insulating layers [3]. However, most of the practical cable uses a semiconducting screen between conducting and insulating layers which has considerable effects on cable line parameters as well as wave properties [7, 8]. Therefore the need for modification in the existing impedance and admittance model [1] of UG cable to include the effect of the semiconducting screen was arisen. After several attempts [9-12], a complete and explicit mathematical model of cable impedance considering the effect of the semiconducting layer was first derived in [13] by solving Maxwell’s equations for a two-layered conductor which was later verified using circuit and numerical approach [14, 15]. These works and subsequent works [10, 16-20] investigated the effects of the variation of semiconductor resistivity and dielectric properties on line parameters as well as wave properties of the cable considering different factors like frequency, pressure and temperatures of semiconductor sample, etc. both theoretically and experimentally. These investigations were mainly emphasized on reporting the role of the materialistic properties of the semiconducting screen on attenuation characteristic and deformation of propagated signal, especially at high frequency. This paper aims to understand and analyze the effects of the variation of electrical and geometric properties of the semiconducting screen on all three primary line parameters namely resistive, inductive and capacitive part of the UG cable over a wide range of frequency. The influence of different parametric variations of the semiconducting screen on wave properties of the cable is also studied. The line parameters, as well as wave properties of the cable with semiconducting screen, are obtained from the expressions of impedance and admittance of the cable. The expressions of impedance and admittance are derived using the loop current method of circuit analysis. This method provides a way to incorporate the effect of the semiconducting screen in the expressions of cable impedance directly without recalling the theory of double-layered conductor theory as done in [13, 14]. A comparative analysis between the cable with and without semiconducting screen based on the effect of parametric variations of the semiconducting screen on line parameters and wave properties of the cable is performed. The analysis shows that by varying electrical and geometric properties of the semiconducting screen in cable considerable changes in the line parameters can be made especially at high frequency compared to that of cable without semiconducting screen which in turn influences the wave properties. Also, by Effect of the Parametric Variations of Semiconductor Screen on Line Parameters and Wave Properties of Underground Cable Swarnankur Ghosh, Supriyo Das