ASSESSMENT OF DESTRUCTION OF POLYMER ELECTRICAL INSULATING MATERIAL DUE TO PARTIAL DISCHARGES AND RADICALCHAIN FRACTURE MECHANISMS

Abstract

The article is devoted to the development of a method of non-destructive testing of the insulating
material of cable systems. The destruction of a polymer material caused by a radical chain
mechanism of destruction is considered. The mechanism of destruction of polyethylene caused by
electron and ion bombardment under the action of partial discharges (PD) is given. The formation
of cross-links associated with the activation of double bonds during the transfer of electronic excitation
energy from a polyethylene chain is shown. When exposed to CR, the number of
transvinylene-type double bonds reaches saturation with an increase in the dose of absorbed energy.
The PD diagnostic system using a complex of characteristics of PD inclusions (SB, qCR, hB) by
the amount of heat generated (Q) and ignition voltage (UV) obtained by the developed software is
effective both for assessing the current state of insulation and for predicting its residual resource.
The detected CR sources indicate the presence of inclusions in the cable insulation. Within the
framework of the conducted research, a neural network (NS) model describing the architecture of
a cyber-physical system power cable lines (PCL) for predicting the resource of EM cable electrical
networks was built. The algorithm of the adaptive system operation, selection of parameters
and training of the NS with subsequent prediction of the PCL resource is synthesized, which makesit possible to increase the reliability of the PCL by reducing the time to create the optimal configuration
of the NS. The obtained NS model can be effectively used for the analysis of thermal fluctuation
processes occurring in the control object – PCL, and the prediction of the behavior of the
object. The method of diagnosis of IM CL in operating conditions is given. The analysis of the
obtained results showed that the measurement of the parameters of the PD allows us to assess the
impact of various factors on the electrical insulation of the CL and determine the degree of its
degradation. PD is a measure of the degree of electrical aging.