Research On The Surface Flashove Of Composite Insulator Material With Space Charge

The research of surface flashover voltage has been a hot topic,and various theories have been developed.Based on the experimental research,a lot of methods to improve the flashover voltage of the surface have been put forward.In various factors,little research on space charge effect on the flashover voltage,with the material aging degree increase,material trap density and space charge trapping the formation of space charge layer,a formed material is added in the field,on the other hand,there is a large amount of energy and space charge polarization,the surface flashover voltage influence can not be ignored.Study on the effect of surface flashover voltage,can provide guidance for material modification,further improve the insulation flashover voltage,explore the space charge effect on the flashover process,will help expand the insulation mechanism of material surface flashover.In this paper,through the method of artificial corona aging,the aging of silicone rubber samples with different length,with the increase of aging time,the material inside the trap density change,the injected charge trapping electrode is formed,contains the space charge number from less to more samples in the interdigital electrode under the surface flashover voltage test,impact study of space charge on surface flashover voltage.The artificial corona aging test device was set up to obtain the aging samples with different traps.And set up the flashover voltage of the test platform,write the boost constant rate control software,high voltage DC power supply control to boost output voltage based on the uniform rate,reduce the influence of voltage waveform on flashover voltage,greatly reduce the dispersion of the experimental data,is the guarantee of successful experiment.In the second,the inner trap density of the aged material is reflected by the curve of the conductance.The slope of the logarithmic coordinate system of the conductance current represents the space charge trapping rate.The conductivity current test is influenced by many factors,and the repeatability is poor,which is more sensitive to the pressure gradient and the step up interval.For the development of a single chip platform,gradient boosting system based on interval,by reading the sampling resistor voltage value,the integrated operational amplifier,automatic conduction current after computing the values are sent to the computer terminal.Finally,the electrical aging threshold was obtained by curve fitting,and the trap density was estimated.The results show that the space charge of the surface flashover current column have important influence on development,on the one hand,space electric field and space charge formation,the surface flow in the column charge effectively,accelerate the speed of separation flow in the column of positive and negative particles,particles have positive and negative electric field weakening effect on the electric field between the electrodes;on the other hand,the space charge layer so that the electric field between the electrodes to make bending surface flow along the column surface,affected by the surface morphology becomes larger,the flashover voltage will rise once in extent.The accumulation of space charge polarization contains a large amount of energy,space charge release large amounts of energy involved in surface flashover,surface charge and space charge by gravity,surface charge dissipation is relatively difficult.The surface flashover voltage decreases sharply.To improve the surface flashover voltage,it is necessary to suppress the accumulation of surface charge,and to take into account the distribution of space charge and the polarization energy.