Study On Electric Field Sudden Change Of Compisite Insulators And Unidentified Flashover

In comparison with porcelain insulator, composite insulator has many advantages, such as small weight, anti-contaminant etc. All of these make the whole power system run more steadily. However, the reason of some flashovers hasn't been identified yet. Aim at this present condition, the method that this literary grace uses the theories and combines together physically. The article is focused on the electric field sudden change and the damp air electricity leave of composite insulators in order to find out the reasons of unidentified flashovers.We use the composite insulator sub- examination instrument to measure the 220 kV,110 kV composite insulator electric field physically. Carrying on the analysis to the data of the diagraph, we discover to synthesize to the composite insulator electric field existence sudden change the phenomenon. The electric field curve presents " bathtub" shape characteristics.Also, in order to validate the test data from the laboratory, the electric field of sudden change has been computed in SCSM (Surface Charge Simulation Method). There plot is in accordance with the real data. Maybe it proves the capacity of composite insulator to power lines and ground has an important influence in non-uniform voltage distribution. According to the result of the electric field distribution computation non-uniform potential distribution has a relationship with appearance and surface dielectric materials of composite insulators.The topic that we study is the electric field sudden change of the composite insulator. The augmentative electric field strength of nasty play make the electricity halo of the composite insulator sub- both ends turn worse. Because the electricity halo , appearing the space electricity ion regiment at the sub- both ends, Lowering the insulate strength in the center parts of the composite insulator. While taking place some flashovers, the both ends of the electricity ion regiment broke through first, then the center parts of the composite insulator air clefts broke through, becoming the passage of the flashover , thus with cause the Unidentified flashovers of the circuits.Therefore, it is very important to smooth the electric field of composite insulators. Firstly, composite insulators need equalizer circle at both of the ends; further more, better shape and more reasonable dielectric proportion should be researched.. According to the experiments and practice, testing electric field is an effective method to find the faults of composite insulators.