基于电场优化的主变中性点避雷器试验辅助屏蔽装置  

The Main Transformer Neutral Point Arrester Test Auxiliary Device Based on Electric Field Optimization

作　　者：陈高汝 李长元 邹几欢 陈晖 纪哲强 许明龙 鲁坤[2] 兰生[2] CHEN Gao-ru;LI Chang-yuan;ZOU Ji-huan;CHEN Hui;JI Zhe-qiang;XU Ming-long;LU Kun;LAN Sheng(Fuzhou Power Supply Company,State Grid Fujian Electric Power Co.,Ltd.,Fuzhou 350000,China;Fuzhou University,Fuzhou 350108,China)

机构地区：[1]国网福建省电力有限公司福州供电公司,福州350000 [2]福州大学,福州350108

出　　处：《电力学报》2022年第1期18-25,共8页Journal of Electric Power

基　　金：国网科技计划项目(5213102100A5)。

摘　　要：为避免绝缘损坏,变压器中性点避雷器会定期进行直流泄漏试验。在该试验前,操作人员需登高拆卸放电间隙或者在放电间隙间放置绝缘介质,传统操作方法有一定的危险性且效率较低。为解决此问题,设计了一种基于电场分布优化的新型主变中性点避雷器高压试验辅助屏蔽装置,即在放电间隙中间加设复合板作为屏蔽装置,增加间隙的击穿场强,改善间隙间电场分布。采用Ansys Workbench软件仿真计算,探究有、无安装屏蔽装置的放电间隙的电场分布区别。其中放电间隙电极均采用铜材料,屏蔽装置安装于放电间隙中,与电极接触的板为铝板,与铝板复合的板为聚乙烯板。棒—棒电极距离为110 mm,仿真时分别对避雷器侧的电极施加+110 kV与-110 kV电压。无屏蔽装置时,间隙局部电场最大场强可达4.220 kV/mm;加装屏蔽装置,在铝板厚度为3 mm的情况下,对不同厚度和直径的复合板进行仿真,得到复合板最佳尺寸为直径250 mm,聚乙烯板厚度4 mm。为避免在放电环境下长期使用屏蔽装置发生板周老化,在其周围加装一圈50 mm的均压环,并在接地端电极尖端加装同样大小和厚度的聚乙烯板,可有效抑制屏蔽装置周围的场强至1.6 kV/mm。仿真结果表明,该装置可以有效地优化间隙间的电场分布,避免间隙被击穿,保证直流泄漏试验结果的准确性。同时,该装置还设计增加了绝缘杆,并在绝缘杆中设有让试验线穿过的通孔。将试验线与升压装置连接,从绝缘杆通孔中穿过再进行加压,防止在加压过程中试验线对变压器外壳以及周围金属架构放电。整套装置不仅能避免操作人员登高操作,保障操作人员与设备的安全,也提高了试验的效率与准确性,因此在电力系统中有着广泛的应用前景。In order to avoid insulation damage,the neutral point arrester of transforme conducts DC leakage test regularly.Before this test,the operator needs to climb high to dismantle the discharge gap or place insulating medium between the discharge gaps,this traditional operation method is dangerous and inefficient.To solve this problem,a new auxiliary device for high voltage test of neutral point arrester of main transformer based on electric field distribution optimization was designed,a composite plate was added in the middle of the discharge gap as a shielding device to increase the breakdown field strength of the gap and improve the electric field distribution between the gaps.Using Ansys Workbench software to simulate and calculate,the difference of electric field distribution between the discharge gap with and without shielding device was explored.The discharge gap electrodes were all made of copper material,the shielding device was installed in the discharge gap,the plate in contact with the electrodes was an aluminum plate,and the plate compounded with the aluminum plate was a polyethylene plate.Rod-to-rod electrode distance was 110 mm in simulation,+110 kV and−110 kV voltages were respectively applied to the electrodes on the arrester side.Without shielding device,the maximum field strength of gap local electric field could reach 4.220 kV/mm;With shielding device installed,the composite plates with different thicknesses and diameters were simulated under the condition that the thickness of aluminum plate was 3 mm,and the best size of composite plate was 250 mm in diameter and 4 mm in thickness of polyethylene plate.In order to avoid the aging of the shielding device in the discharge environment for a long time,a circle of 50 mm equalizing ring was installed around the shielding device,and a polyethylene plate with the same size and thickness was installed at the tip of the electrode at the grounding end,which could effectively restrain the field strength around the shielding device to 1.6 kV/mm.The simulatio

关 键 词：直流泄漏试验 放电间隙 中性点避雷器 电场优化 

分 类 号：TM862[电气工程—高电压与绝缘技术]