A Method for Simulating Abnormal Heating Internal Interface of Composite Insulator Based on Electromagnetic Heating

Abstract

Decay-like fracture is a new kind of fracture phenomena of composite insulator occurring in recent years. Abnormal temperature rise in 500kV composite insulators high-voltage end is found by the infrared temperature measurement before the decay-like fracture occurs. In order to simulate the overheat conditions and carry out artificial accelerated aging tests, an experimental method based on electromagnetic heating is put forward in the paper. A metal defect is put in the interface between silicone rubber housing and fiber reinforced plastic (FRP) core rod. The composite insulator sample is put in the high frequency magnetic field. Due to the eddy effect, the metal defect will heat. Partial internal heating in the sheath-core interface is achieved in the paper, which is the same as the abnormal overheated composite insulators online. During the experiment, the FPR core rod is heated by the defect, deteriorates, and produces a lot of gas, which cause the damage of the silicone rubber housing. After the experiment, the FPR core rod samples are analyzed by visual observation, scanning electron microscope and Fourier Transform Infrared Spectrometer. It is proved that epoxy resin matrix in the hot environment will be decomposed in the paper.