Research On Influence Of Atmospheric Parameters On Electric Equipment Outer Insulation In High Elevation Zone

Researching and analyzing on the test results of the influence of atmospheric parameters on outer insulation discharge voltage and its various emendation methods, it can be concluded that: with the change of relative air density , its humidity ratio H/ ? will also change even though the absolute vapor mass (absolute humidity H) of the air is constant. Consequently, the influence degree of the humidity on the discharge voltage should change, too. Only when it takes humidity ratio H/? as independent variable instead of absolute humidity H in researching and calculating the influence degree of the humidity on the discharge voltage, the emendation coefficients of relative air density and humidity can be independence, and can reflect the influence degree of atmospheric parameters on outer insulation discharge voltage actually. The article adopts "humidity ratio" integrated emendation method and other two traditional emendation methods in emendation calculating on several group test results. The tests are : simulating test in artificial climate room on 110kV substation equipment of Yangbajing, Lasa and Yanghu by Xi'an High Voltage Lab; power frequency voltage discharge test of ZS-110 by Yunnan provincial electrical research academy. It compares and analyses the equipment test voltage emendated to standard atmosphere conditions with the equipment nominal withstanding voltage. And then it concluded that: the emendation value educed by "humidity ratio" integrated emendation method is basically equal or close to the equipment nominal withstanding voltage; but the values by two traditional emendation methods are mostly higher.It also proves that, "humidity ratio" integrated emendation method is more perfect than any other methods, and it can reflect the influence degree of atmospheric parameters on electrical equipment outer insulation discharge voltage actually. The method should be spread in designing high elevation power projects.Based on instance of Mania project, the article raises an insulation coordination method for high elevation zone and the criterions fulfilling the insulation coordination conditions. It also has calculated the demanding values of withstanding voltage of all voltage levels equipment, and the results of outer insulation coordination. At the mean time, it proves the success of applying "humidity ratio" integrated emendation method in the Mania project.