复合支柱绝缘子污闪是变电站的主要故障之一，优化伞形参数能够有效改善其污闪性能。本文提出一种基于复合支柱绝缘子物理模型的伞形参数优化研究方案。首先，通过仿真计算研究大伞伞伸出P1和伞间距s对电场分布的影响，以减小伞裙沿面平均电场Eav或者伞裙沿面不均匀系数f为优化目标，得到参数优化范围为70 mm≤P1≤90 mm、72 mm≤s≤92 mm，为后续伞形参数优化试验提供参数范围。然后，以具有不同伞形参数的复合支柱绝缘子物理模型为试品，开展人工污秽试验，观测试品的闪络电压、紫外放电光子数和电弧发展路径，得到最优（闪络电压最大）伞形参数为P1=90 mm、s=72 mm，优化后试品的污闪电压提高了18%。最后，综合分析仿真与试验结果，并调整了伞形参数的优化判据。伞裙沿面平均电场Eav主要影响闪络电压U50%，且Eav越小的试品，U50%越大，电弧的桥接和跨接现象越弱；伞裙沿面不均匀系数f主要影响紫外放电光子数，f越小的试品，紫外放电光子数越少。在电场伞形优化研究中，Eav的优先级应高于f，爬电系数尽量接近3.5-4.0。

The pollution flashover problem of composite pillar insulators, as one of the major faults in substations, can be effectively improved by optimizing the shed parameters. This paper proposes a shed parameter optimization method based on the physical model of composite post insulators. Firstly, through simulation calculation we studied the effects of the extension of the large shed overhang P1 and the shed spacing s on the electric field distribution. With the optimization target of reducing the average electric field Eav along the skirt or the non-uniformity coefficient f along the skirt, the parameter optimization range was obtained as 70 mm≤P1≤90 mm and 72 mm≤s≤92 mm, providing a parameter range for subsequent shed parameter optimization experiments. Then, using physical models of composite post insulator as test samples, artificial pollution tests were carried out to observe the flashover voltage, ultraviolet discharge photon number, and arc development path of the test samples. The optimal(maximum flashover voltage) shed parameters were obtained as P1=90 mm and s=72 mm, and the pollution flashover voltage of the optimized sample was increased by 18%. Finally, the simulation and experimental results were comprehensively analyzed, and the priority of simulation optimization criteria was proposed. The average electric field Eav along the skirt mainly affects the flashover voltage U50%, and the smaller the Eav of the test sample, the larger the U50% and the weaker the bridging and crossing phenomena of the arc; the non-uniform coefficient f along the skirt mainly affects the ultraviolet discharge photon number, and the smaller the f of the test sample, the fewer the ultraviolet discharge photon number. In the optimization strategy based on electric field simulation, the priority of Eav should be higher than that of f, and the surface creepage coefficient should be close to 3.5-4.0.

TM216??????

国家自然科学基金项目（面上项目，重点项目，重大项目）