Positive Switching Impulse Flashover Performance And Voltage Correction Of Rod-Plane Air Gaps At Lower Atmospheric Pressure

Switching impulse flashover performance in the air gap is very important to external insulation design. In the stratagem of the power transmission from the west to the east in China, designing and constructing UHV or EHV overhead transmission lines must get across in these complex climate western areas of high altitudes. Refering to abundant inland and oversea data and using the large scale artificial climate chamber of the Key Laboratory of High Voltage Engineering and Electrical New Technology of The Education Ministry in Chongqing University,this essay carries a series of experimentations of positive switching impuls flashover performance and correction in the rod-plane air gap under lower atmospheric pressure and compares with real spot. The main research of this dissertation are as followed:(1) Carrying the test of positive switching impulse flashover in the rod-plane air gap of the 500, 1000 mm and 1500 mm three kinds of length in the artificial climate chamber under lower atmospheric pressure, the flashover performance and 50% flashover voltage correction methods are researched.(2) Choosing the rod-plane air gap of 1000mm length, The influences of humidity to flashover performance and 50% flashover voltage under positive switching impulse are researched in different lower atmospheric pressure.(3) Based on research in the artificial climate chamber, new correction motheds are put forward according to P/P0 and g parameter mothed.(4) Testing in high altitude area spots and comparing the results from the artificial climate chamber. Researching the influence of humidity in rod-plane air gap flashover according to the results in high altitude area and the artificial climate chamber.Through simulating and spot tests, the main conclusion of the analyze results are as follows:(1) The deviation increases adopting the correction mothed of P/P0 at lower atmospheric pressure derived from humidity and it has a bigger error the pressure lower. Considering the additional influence of the absolute humidity, the 50% flashover voltages are more exact than before.(2) The results of g parameter correction method is suitable above altitude 2000m when environmental parameters are close to the standard reference conditions. Its error increases when temperature and humidity deviate more from the standard reference...