The Optimization Research of 500 kV MOA without Gap

To improve operational reliability and economic benefits of arrester,the author uses optimization design for 500 kV metal-oxide surge arrester without gap for AC system from three aspects was carried out.First,through the resister technology study,high performance resisters were developed,and its energy absorption capacity is up to 7.8 kJ / kV.Second,on the basis of finite element method optimization calculation for arrester electric field,the latest structure of grading ring is designed and parallel grading capacitor is removed.Through actual potential distribution measurement,maximum uneven coefficient of potential distribution is not less than 12%.Third,by artificial pollution test and study on external shed configuration,internal core structure and thermal stability,the arrester passes Ⅳ-grade pollution classes tests,and finally the reasonability of optimization design of 500 kV metal-oxide surge arrester without gaps for AC system is verified.