Estimation of thermal conditions of insulation in the ANSYS 2D model of link «cable line 6(10) kV - soil» with consideration for movements of soil and relay protection set values

In this article movements of soil and cables during the annual cycle of exploitation are determined, as exemplified by city active cable lines 6(10) kV and test models. The experiments were conducted by measuring the depth of bedding of selected points of cable lines lying in different conditions using the device RIDGID-SeekTechSR-20. The analysis of the acquired data showed that the cable lines movements can lead to formation of dangerous mechanical tension and hollows. For the estimation of thermal conditions of insulation with consideration for probable sizes of the hollows, that are formed during the movements of cable lines in the soil, 2D models of link “cable line - soil” were developed with ANSYS. Thermal conditions of insulation were analyzed during operation modes and short-circuit regimes with the consideration for relay protection and automation set values. Probable zones of insulation overheating are determined, the equivalent thermal circuit for admissible currents calculation is corrected based on the results of modeling.