Effect of impulse voltage on solid insulation

Abstract

One of the main problems of the high voltage engineering is the degradation of the insulation of the solid insulating material.It has been revealed through the several researches and studies that the high voltage power equipment are directly and mainly subjected with the spark over voltage caused by impulse voltage like lightening strokes and switching action.The sphere-sphere electrode arrangements are mainly used for the measurement of the peak values of the high voltages as adopted by the IEC and IEEE. Generally in the electrical power equipment, the standard sphere gaps are widely used. The effect of the impulse voltage on different insulations like Nomex,Lather Minilex,White Minilex and Glass Cloth has been studied.To study and observe the effect on insulation of the solid material due to breakdown mechanism, the insulation samples are collected after the application of the impulse voltage test and analysis is done with the help of scanning electron microscope(SEM).A standard sphere of 25cm in diameter is used to measure the effect of impulse voltage. Finally the experimental data is generated and compared with the theoretical and the graphical interpretation is done. Hence the determination of the breakdown voltage of various insulating material gives a major area of interest to the electrical engineers and in particular to the high voltage engineers.Therefore,the possibility of developing solid insulating materials with excellent breakdown strength is viable through study and research.The few basic and important topics affecting the breakdown and study of different composite insulating materials are reviewed.