A mathematical model of a power cable current-conducting core heating taking into account electrothermal processes in cable line digital twins

This article deals with the implementation of diagnostics and monitoring of the current-conducting part and insulation state of high-voltage cable lines in real time using digital twins. The problems of thermal accounting and the features of modeling electrothermal heating processes in power cables are determined. A mathematical electrothermal model of a power cable for a cable line digital twin is proposed, based on the decomposition of its dynamic thermal resistance into the sum of exponential components, which makes it possible to calculate the instantaneous values of the heating temperature of a current-conducting cable core in real time with insignificant amounts of calculations on the discretization interval of the calculation. The results of calculation using the heating temperature model for a single-core power cable with a three-phase short circuit in the network are presented.