Simulation of Structural, Thermal and Electrical Load for High Voltage Ceramic Cap and Pin Disc Insulator Assembly

This paper studies mechanical- stress-strain, thermal- temperature distribution, electrical potential and electric field distribution for 11 kV, single ceramic cap and pin disc insulator assembly used for high voltage transmission and distribution systems. The coupled field finite element computer simulation is carried out by using a commercially available software package, which allows quantifying the effects of insulator assembly on where structural, thermal and electrical load distribution considered simultaneously. The simulation result shows stress concentration due to application of structural, thermal, and electrical load. The stress was maximum on pin and moderate on sealing material and disc. Similarly in electrical analysis, nodal electrical potential and electrical field distribution observed decreasing from bottom pin of insulator assembly to top cup end of insulator model. Remarkable stresses, temperature, electrical potential and electrical field rise was not observed at porcelain but mainly observed in critical areas like triple junction (pin-porcelain, porcelain-cup junction of insulator assembly), despite high tension, high temperature of conductor and high voltage-current. With continuous use of an insulator and varying environmental condition, this high tension, temperature and high voltage may cause small crack in sealing material and the insulator disc material. This may reduce performance or cause failure of an insulator without any prior notice.