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.