The Effect Of Booster Shed On External Insulation Of 500kV Transformer High-voltage Bushing Under Rain Condition

Rain flashover accidents occur frequently on transformer bushing.In order to investigate the external electric field and rain characteristics of 500 kV high-voltage bushing with booster shed under rain condition,in this paper,electric field simulation and rain experimental research are carried out,which are as briefly shown:(1)Full-scale model of condenser bushing for 500 kV transformer is established and simulated.Based on the electric field between shed air gap and that along shed surface,the shed parameters are optimized.It obtained the effect rule of shed spacing and overhang on bushing external electric field under rain condition.And it proposed an optimized shed parameter for the bushing.Also,it revealed the different effect rules of shed parameter under rain condition and contaminated condition.(2)Booster shed is added to bushing models with different shed parameters.Based on simulation research,the effect of booster shed on bushing external electric field under rain condition is studied,and its effectiveness to improve insulation under rain condition.And it revealed the different effect rules of booster shed under rain condition and contaminated condition.(3)To further investigate the influence of booster shed.The effects of booster shed overhang,installation quantity,and mounting position are studied based on the bushing model with optimized shed parameter,and a preferential installation of booster shed is proposed.(4)Experimental research is carried out on bushing mounted with booster shed to investigate the effect of booster shed on rain characteristics.Based on image processing technique,it analyzed the quantity and length of rain curtains on sheds,and the effect of booster shed quantity and installation position is revealed.It proposed a preferential installation of booster shed subject to rain characteristics,and it conforms to the simulation result.