The flashover of insulator strings occurring at normal working voltages undercontaminated/polluted conditions, obviously deserves serious consideration. Though much researchhas been gone into pollution-induced flashov...The flashover of insulator strings occurring at normal working voltages undercontaminated/polluted conditions, obviously deserves serious consideration. Though much researchhas been gone into pollution-induced flashover phenomena but grey areas still exist in ourknowledge. In the present experimental study the breakdown (flashover) voltages across gaps oninsulator top surfaces and gaps between sheds (on the underside of an insulator), also the flashoverstudies on a single unit and a 3-unit insulator strings were carried out. An attempt has been madeto correlate the values obtained for all the cases. From the present investigation it was found thatresistance measurement of individual units of a polluted 3-unit string before and after flashoverindicates that strongly differing resistances could be the cause of flashover of ceramic discinsulator strings.展开更多
In heavy metal industrial areas,the issue of insulation flashover caused by metal contamination on the external insulation of transmission lines has become increasingly prominent.This paper investigates the U160B/155 ...In heavy metal industrial areas,the issue of insulation flashover caused by metal contamination on the external insulation of transmission lines has become increasingly prominent.This paper investigates the U160B/155 porcelain insulator,examining how iron,copper and zinc metal contaminations affect its AC flashover characteristics.Furthermore,combining with leakage current,the flashover mechanism of the insulators under the influence of metal particles is analysed.The research results indicate that as the metal content increases,the insulator's flashover gradient(E_(L))decreases by up to 2.3%-17.2%.Different metal compositions exhibit consistent mechanisms,similarly impacting insulator's dielectric strength with copper showing slightly weaker effect.And then,based on the mechanism of metal particles'influence on the insulator's AC flashover,a formula for calculating E_(L) is proposed and the calculated results are basically consistent with the experimental conditions.Finally,different metal compositions have similar effects on the leakage current,with an increase in metal content leading to an increase in the critical leakage current,which gradually tends to saturation.The research findings of this paper can provide references for AC flashover prediction,assessment and prevention of external insulation in areas with metal contaminants in pollution sources.展开更多
文摘The flashover of insulator strings occurring at normal working voltages undercontaminated/polluted conditions, obviously deserves serious consideration. Though much researchhas been gone into pollution-induced flashover phenomena but grey areas still exist in ourknowledge. In the present experimental study the breakdown (flashover) voltages across gaps oninsulator top surfaces and gaps between sheds (on the underside of an insulator), also the flashoverstudies on a single unit and a 3-unit insulator strings were carried out. An attempt has been madeto correlate the values obtained for all the cases. From the present investigation it was found thatresistance measurement of individual units of a polluted 3-unit string before and after flashoverindicates that strongly differing resistances could be the cause of flashover of ceramic discinsulator strings.
基金supported by the Natural Science Foundation of Chongqing,China(Grants CSTC2024YCJH-BGZXM0060,CSTB2023NSCQLZX0021)Central University Basic Research Funds Project(Grant 2023CDJYXTD-005).
文摘In heavy metal industrial areas,the issue of insulation flashover caused by metal contamination on the external insulation of transmission lines has become increasingly prominent.This paper investigates the U160B/155 porcelain insulator,examining how iron,copper and zinc metal contaminations affect its AC flashover characteristics.Furthermore,combining with leakage current,the flashover mechanism of the insulators under the influence of metal particles is analysed.The research results indicate that as the metal content increases,the insulator's flashover gradient(E_(L))decreases by up to 2.3%-17.2%.Different metal compositions exhibit consistent mechanisms,similarly impacting insulator's dielectric strength with copper showing slightly weaker effect.And then,based on the mechanism of metal particles'influence on the insulator's AC flashover,a formula for calculating E_(L) is proposed and the calculated results are basically consistent with the experimental conditions.Finally,different metal compositions have similar effects on the leakage current,with an increase in metal content leading to an increase in the critical leakage current,which gradually tends to saturation.The research findings of this paper can provide references for AC flashover prediction,assessment and prevention of external insulation in areas with metal contaminants in pollution sources.
