Abstract: As the diameter of the core of the composite post insulator for UHV applications continues to increase, the rationality of the temperature rise retention time of the existing standard heat engine test is worth discussing. In this paper, the thermal conductivity of the composite insulating pillar core is estimated by equivalently simulating the heat transfer pattern in the composite. Using the finite element simulation method, the mathematical model of the composite insulating pillar core was established by ANSYS software, and the estimated thermal conductivity and thermal test environment conditions were input to simulate the internal temperature change process of the pillar core. We set the type test, set the monitoring point in different thickness positions inside the pillar core, and record the curve of the internal temperature of the core with time under the uniform heating state in real time. The test result shows that the internal height of the pillar core reaches (50±5) ℃, which is 62800 s, which is much larger than the thermal test time of 43200 s. The existing test methods have defects. The simulation temperature and the actual temperature rise error of the product are 6.2687%, 6.5026%, and 5.5696%, respectively. The simulation results are of good accuracy.

Key words: composite insulating pillar, UHV, thermal conductivity, finite element simulation method, the heatengine test, composite