Determination of pollution flashover behaviour of high voltage insulators by the finite element method

IV SUMMARY Master Thesis Determination of Pollution Flashover Behaviour of High Voltage Insulators by The Finite Element Method Muhsin Tunay GENÇO?LU Fırat University Graduate School of Natural and Applied Sciences Department of Electrical and Electronics Engineering 1997, Page: 81 High voltage insulators are supposed to provide a continuous and safety insulation in energy transmission systems. However, pollution layer that occurs on the surface of insulator, decreases the performance of insulators and causes surface flashovers and therefore short circuit failures. Several natural and artificial test methods had been developed to determine the surface flashover performance of the insulators, which will be used in polluted region. In addition, analytical calculations have been carried out on the models. AR model can be used to model the surface pollution layer of the insulator. AR model is a real model that open the surface of the insulator along the leakage length to a plane. Calculation of the pollution resistance serial to the discharge which determines the surface flashover performance can be carried out on the models and using computer methods. In this work, pollution flashover and physical mechanism of it have been defined and its importance has been explained. Determination of the flashover behaviour of the insulators via natural and artificial tests and insulator equivalent models have been examined, comparatively. In order to calculate the variation of the resistance serial to the flashover, AR models of the insulators has been constructed seperately for 5 insulators that has been examined and later their resistance variations have been calculated applying FKM analysis to the models. Computational results are compared with the experimental results. Key Words: Insulator, Finite Element Method, AR model, Pollution flashover, Pollution resistance.