特高压干式油气套管内绝缘结构的优化设计

Inner Insulation Structure Optimization for Ultra High Voltage Resin Impregnated Paper Oil-SF_6 Bushing

针对使用经典解析公式设计套管电容芯子的局限性,改进了套管的传统等裕度设计方法。以特高压干式油气套管为研究对象,考虑杂散电容和温度对套管芯子电场分布的影响,建立了套管芯子改进等裕度设计方法的数学模型。在此基础上,联合有限元电热耦合计算和粒子群优化算法对该套管的内绝缘结构进行了优化设计。根据以上优化设计结构,试制了油气套管样机,并进行了全部型式试验,结果表明,提出的改进等裕度设计方法可实现油气套管芯子径向场强、轴向场强和极板间局部放电裕度的均匀分布,且芯子局部放电裕度值由0.925提升到1.155,验证了改进等裕度设计方法的实用性。

Focusing on the limitations in bushing condenser design with the traditional analytic formulas,an equal margin design method is developed.Taking the ultra high voltage resin impregnated paper oil-SF6 bushing as an object and considering the influences from stray capacitance and temperature,the mathematical model for the improved equal margin design is established.Then the inner insulation structure is optimally designed by combining finite element method electro-thermal coupling calculation and particle swarm optimization algorithm.The bushing prototype is fabricated according to the optimized design and the availability of this equal margin design scheme is confirmed by all types of tests.It can be realized to uniformly distribute field intensity along the bushing condenser and the partial discharge margin between the adjacent foils,and the partial discharge margin can be heightened from 0.925 to 1.155.