Simulation of the Composite Electric Field on 170 kV Disconnector Using the Finite-Element Method

In this study, the e ff ects in terms of electric stress of composite voltages on a high-voltage disconnector were investigated. The main purpose of this study is to determine and evaluate the e ff ects of the conditions that may occur in real working conditions but out of the type tests. As for the disconnector model, one phase of a center-break disconnector was considered. In order to examine the e ff ects of composite voltages on high-voltage disconnectors, a model is de fi ned in the Comsol Multiphysics program. Di ff erent types of voltages such as operating voltage, 50 Hz test voltage, lightning impulse voltage, and composite voltage, were applied to the 170 kV disconnector model separately. After applying a composite voltage consisting of power frequency voltage and lightning impulse voltage to the disconnector, electric potential and electric fi eld distributions were obtained. It has been observed that the maximum electric potential and the maximum electric fi eld strength values on the disconnector are higher when composite voltage is applied than when non-composite voltage is applied to the disconnector. It is observed that the intensity of the electric fi eld lines increases near the contacts of the current-carrying arm and the main contacts of the disconnector.