Studying Critical Flash Over of Different Types of High Voltage Insulator

Abstract

The critical flashover CFO of an insulation structure is commonly used todescribe the insulation structure lightening impulse strength. In this work,first CFO of polymer and porcelain each alone was measured and then, a newstructural arrangement is represented to measure (CFO). This arrangementsconsists of three layers; fiberglass is placed between two layers of polymer andporcelain .All insulation materials are examined in dry and wet condition withpositive and negative lightening impulse under (15,25 and 35) KV. The criticalflashover voltage (CFO) of insulator is distributed on certain surface alongwith fiberglass distribution poles as an insulator. Also altitude of poles istaken into consideration in calculating critical flashover voltage for bothinsulator and structure. (CFO) voltages are added from fiberglassdistribution pole to basic insulation component and are calculated based onthe test result of the (CFO). The above measurements indicated that the totalCFO voltage of new arrangements insulator under dry condition is muchhigher than under wet condition for the same impulse polarity and tested polelength.