Research On Preparation And Rain Flashover Characteristic Of Electric Equipment External Insulation Super-ydrophobic Surface

Recently,with the continuous improvement of anti-pollution technology,rain flashover of electric equipment has gradually become the weakness of external insulation of power system,which threatens the stability of external insulation.The common anti-rain flashover measures have many problems,and can't meet the need for anti-rain flashover performances of electric equipment.Because of their excellent super-hydrophobicity,the super-hydrophobic surfaces have potential application in the area of anti-rain flashover of electric equipment.However,the conventional preparation methods of super-hydrophobic surface have disadvantages of only being suitable for substrates with flat surface and small scale preparation,besides complex process.These disadvantages restrict the promotion of super-hydrophobic surface in the area of anti-rain flashover of external insulation.This paper presents a new method for preparing super-hydrophobic surfaces.The chemical reaction,surface morphology,and hydrophobicity of the as-prepared surfaces were investigated.The rain flashover characteristic of the as-prepared surface was studied.The electric field distribution characteristic of droplets on the super-hydrophobic surfaces was analyzed.The work focuses mainly on the following content:(1)A new method for preparing the super-hydrophobic surfaces was presented.The super-hydrophobic surfaces were fabricated by the depositing the silicone rubber and epoxy resin molecules grafted nano-silica particles on glass substrates.The chemical reaction,surface morphology,and hydrophobicity of the as-prepared surfaces were investigated.The super-hydrophobic insulator surface was fabricated.The results show that the as-prepared surfaces exhibit excellent super-hydrophobicity;The method proposed is suitable for electrical equipment insulation components with complex structure and batch production;super-hydrophobic insulator surface can inhibit the formation of water curtain or continuous water flow.(2)The rain flashover characteristic experiments of the as-prepared surface were carried out.The rain flashover voltage at different gap length was measured.The influences of rainfall,rainwater conductivity,and wind speed on rain flashover characteristic were investigated.The rain flashover experiments of silicone rubber and glass surface were also conducted for comparison.The results show that the rain flashover voltage of super-hydrophobic surface is much larger than that of silicone rubber and glass surface under different conditions of gap length,rainfall,rainwater conductivity,and wind speed;As rainfall,rainwater conductivity,and wind speed change,rain flashover change range of super-hydrophobic surface is far less than that of silicone rubber and glass surface;The super-hydrophobic surface can keep the rain flash voltage high under different condition,which indicates its excellent rain flashover characteristic.(3)The electric field distribution characteristic of droplets on the super-hydrophobic surfaces was studied.Three kinds of models,one droplet and two droplets on super-hydrophobic surfaces,and several droplets on the super-hydrophobic insulator surface,were designed and simulated.Electric field distributions were analysed in the three kinds of models.Electric field distortion rate as a function of water contact angle was also investigated.The results show that,in the three kinds of models above,the electric field distortion is found in the area nearby the driolet on the super-hydrophobic surface.The highest point of electric field changes from triple junction point of droplet to air region between droplets when the distance of droplets is small enough;The electric field distortion rate all gradully decreases with the increasing of contact angle.The super-hydrophobic surfaces can effectively reduce the electric field distortion rate of external insulation surfaces,inprove the rain flashover voltage,and exhibit excellent rain flashover characteristic.