Research on External Insulation Characteristic Test of 1000kV AC Transmission and Substation Equipment

By mimic real configuration test on UHV transmission line, this paper researches the external insulation discharge characteristics of power frequency, switching impulse and lighting impulse on AC transmission and substation equipment air gap, researches the discharge characteristics of power frequency, switching impulse and lighting impulse on heat stable extending radius flexible bundle conductor (bus) , bundle conductor, tubular bus, researches the Influence of high altitude to different non-soluble deposit density and inhomogeneous pollution accumulation to insulator pollution withstand voltage, based on the 1000kV AC power transmission transformation project from the southeast in Shanxi province to Jingmen of Hubei province. The relationship curves between gap and discharge voltage have been gained by switching, lightning and power frequency voltage test on UHV 4-bundle conductor and tubular bus to the substation structure air gap. The relationship curves between gap and discharge voltage have been gained by switching, lightning and power frequency voltage test on grading ring of the typical devices to structure cylinder air gap. The calculation formula of 50% lightning impulse discharge voltage has been gained for 4 bundle conductor, tubular bus and ring to structure cylinder gap. The test of influence of impulse front time on structure gap discharge voltage has been done. Gap coefficients of 4-bundle conductor, tabular bus and grading ring to earth have been gained. Influence of high altitude on insulator pollution withstand voltage, Influence of non-soluble deposit density on insulator, Influence of inhomogeneous pollution accumulation on pollution withstand voltage and the correction coefficient of inhomogeneous pollution accumulation have been obtained by test and study, may be referenced in UHV power engineering.