ANALYSIS OF THE ELECTROMAGNETIC FIELD IN CABLE SYSTEMS WITH INSULATION FROM POLYMER MATERIALS

Abstract

The article is devoted to the calculation of the electromagnetic field strength (EMF) in the insulating material of a power cable (SC). The magnetic field of a single sample of the APvPu-10 1x240/70 cable was investigated. Theoretical information is given for calculating the strength of an electrostatic axisymmetric field based on the solution of Fredholm integral equations in a piecewise homogeneous linear polymer insulation with inclusions. Models are constructed for calculating and analyzing the intensity distribution of inhomogeneous electric fields in a dielectric medium with inclusions of different areas and with different electrophysical parameters (filling). When the EMF passes through various materials filling the inclusion, the absorption of wave energy by these substances is observed. Based on the simulation performed using the Comsol program, the analysis of EMF at the interface of dielectric media between spherical micro-inclusion and the main insulation was performed. It is shown that in solid dielectrics, conductors, EMF absorption is significant. If a wave meets any conductor, then most of its energy is absorbed by it. The presence of inhomogeneities in the insulation at the insulation – inhomogeneity interface causes jumps in the electric field strength 1/2, 2/3. The simulation and analysis of the electric field voltage distribution in the defect region were carried out and it was found that with increasing Sdef, the amplitude of the magnetic induction surge (B) at the first boundary of the defect increases. On the second border, the opposite is true. With increasing Sdef. the depth of the induction failure (B) increases. However, while maintaining the overall picture, the values of dips with different types of filling inclusions are different: – the greatest gradient is observed when filling with water, the smallest when filling with carbon plus cross-linked polyethylene (C + SPE). Thus, it can be a diagnostic parameter of the quality of the insulation of the IC. The results of the work are of interest in solving a complex of problems related to various aspects of electromagnetic compatibility and reliability of functioning of electric power systems.