A calculation model for determination of impedance of power high voltage single-core cables with polymer insulation

Abstract

Introduction. The wave parameters of power cables with polymer insulation differ significantly from the parameters of overhead lines and power transformers. As a result, there are more and more objects in electrical networks for which the occurrence of complex multi frequency transients, accompanied by dangerous overvoltages, should be expected. Purpose. To develop a computational model of the complex impedance of high-voltage single-core power cables of coaxial design required to determine the frequency dependencies of the active resistance and inductance of the conductive core and metal shield, taking into account the surface effect and proximity effect. Methodology. The method is based on solving a system of linear algebraic Kirchhoff equations (SLAE) for magnetically coupled contours. SLAE can be used to calculate conductors taking into account the skin effect and proximity effect. Practical value. The developed model is the basis for determining the characteristic impedance of high-voltage single-core power cables in a wide range of frequencies required to establish adequate criteria for evaluating the parameters of high-frequency effects critical for cross linked polyethylene insulation.

Keywords

• power cables
• complex resistance
• magnetically coupled circuits
• system of linear algebraic equations
• conductor
• screen
• coefficient of irregularity of current distribution