高压直流输电工程换流阀均压电极断裂机理研究  

Study on Fracture Mechanism of Equalizing Electrode of Converter Valve in HVDC Projects

作　　者：肖凯 王振 邹延生 严喜林 梁宁 刘坤 XIAO Kai;WANG Zhen;ZOU Yansheng;YAN Xilin;LIANG Ning;LIU Kun(China Southern Power Grid EHV Power Transmission Company Maintenance&Test Center,Guangzhou 510663,China)

机构地区：[1]南方电网超高压输电公司检修试验中心,广州510663

出　　处：《高压电器》2023年第5期43-51,共9页High Voltage Apparatus

基　　金：中国南方电网有限责任公司技改项目(012000MS62200003)。

摘　　要：均压电极是高压直流输电工程换流阀内冷水系统的重要部件,起到钳制电势和减小泄漏电流的关键作用,但是在运行过程中,均压电极发生腐蚀或者断裂,将导致换流阀阀塔上与内冷水管道接触的金属器件发生腐蚀,内冷水系统发生渗漏、堵塞等,从而使得换流站因设备过热、水管漏水等问题造成的停运事件屡有发生,严重影响直流工程的安全稳定运行。因此,研究均压电极断裂相关机理和原因能够有效减小内冷水系统事故。文中通过分析均压电极在水管内的受力情况,结合铂金材料的特性,首次从剪切强度的角度开展了均压电极断裂分析。文中从材料成分、力学性能、微观结构等角度对均压电极开展了研究,分析了均压电极断裂机理,确定了均压电极断裂原因。文中的分析方法及结论,对高压直流输电工程换流阀均压电极的生产制造、材料选型、运维检修等具有重要参考意义。The equalizing electrode is an important element of the internal cooling water system of converter valve in HVDC transmission project,which plays a key role in clamping the potential and reducing the leakage current.However,during operation,the corrosion or fracture of the equalizing electrode will lead to the corrosion of the metal parts on the converter valve tower in contact with the internal cooling water pipeline,and the leakage and blockage of the internal cooling water system,resulting in frequent out of operation due to such problems as overheating of the equipment in the converter station and water pipe leakage,which seriously affects the safe and stable operation of DC project.Therefore,studying the related mechanism and causes of equalizing electrode fracture can effectively reduce the accidents of internal cooling water system.In this paper,by analyzing the stress of the equalizing electrode in the water pipe and combining with the characteristics of platinum material,the fracture analysis of the equalizing electrode is carried out from the perspective of shear strength for the first time.Moreover,the equalizing electrode is studied from such perspectives as material composition,mechanical properties and microstructure and the fracture reason of equalizing electrode is determined.The analysis methods and conclusions in this paper have significant reference for the production,material selection,operation and maintenance of the equalizing electrode of converter valve in HVDC transmission project.

关 键 词：高压直流输电 换流阀 均压电极 力学性能 工艺 

分 类 号：TM721.1[电气工程—电力系统及自动化]