Research On Electrical Properties And Pollution Detection Method Of Insulators In Haze

Insulators maintain good insulating performance is important to the safe and reliable operation of the transmission line, and its contaminated surface form a huge threat to its good electrical performance.As the special operating environment of the insulator, contamination phenomenon is inevitable. Especially in recent years, fog and haze happen frequently.Faced with this new situation,it is necessary to make study the electrical performance of insulator in haze.This paper begin with the contamination flashover physical process, then discusses various developmental stage of the flashover development and analyzes the conditions and reasons which case insulator flashover. According to the haze’s main components in Beijing contaminants which flashover test needed are allocated. Under the multiple voltage levels and three pollution levels-mild, moderate and severe-flashover tests are made,related voltage and current data were measured and recorded. It is concluded that the flashover voltage decreases with the degree of contamination and moisture increases. And with different wet dirt state insulator leakage current characteristics are different.The phenomenon that insulator equivalent circuit changes with increased levels of wet dirt state are discussed. And base on the features that partial discharge occurs accompanied with current pulse occurs on current waveform,one method of determine the contamination status of the insulator surface was presented.In the end, as for the existed problem of insulator pollution monitoring,a new method for insulator contamination monitoring Proposed.The method use dirt resistance rB of insulator layer as the criterion.The extent of the contamination, humid conditions and environmental factors are all considered in this criterion.Large laboratory tests are conducted to verified this method, prediction result with new method and experimental result are basically consistent, effectiveness and feasibility of this new method is initially confirmed.