高压直流换流阀阳极电抗器缺陷分析

Analysis on Defects of Anode Reactor of HVDC Converter Valve

针对某±500 kV换流站发生的一起换流阀阳极电抗器缺陷开展缺陷原因和产生机理分析。首先对缺陷阳极电抗器和投运阳极电抗器、备品阳极电抗器进行参数测量,测量结果的对比分析表明:20层以内铁心硅钢片脱落使得电感值偏小,但在要求范围之内。然后对缺陷阳极电抗器开展解体检查,分析缺陷产生的直接原因和根本原因,结果表明:渗漏水的直接原因是铁心硅钢片搭接在二次水冷电阻金属水管和金属边框之间,多次放电击穿;根本原因是铁心硅钢片发生了析氢腐蚀和吸氧腐蚀,长期运行振动脱落。针对该缺陷,提出整改措施和运维建议,以期对后续阳极电抗器的运行维护、设计和反事故措施提供参考。

Aiming at a defect of the anode reactor of the converter valve occurred in one±500 kV converter station,this paper analyzes the cause of the defect and studies the generating mechanism.The parameters of the defective anode reactor,the operating anode reactor and the spare anode reactor are measured firstly,and the comparative and analysis results indicate the silicon steel sheet of the iron core within 20 layers falls off,which makes the inductance value smaller,but within the required range.Then the direct and fundamental causes of the defect are analyzed by disassembled inspection on the defect anode reactor.It is pointed out that the direct cause of water leakage is that the silicon steel sheet of the iron core overlaps between the metal water pipe and the metal frame of the secondary water cooling resistance,and the leakage is caused by repeated discharge breakdown.The root cause is the hydrogen evolution corrosion and oxygen absorption corrosion of the iron core silicon steel sheet,and the vibration caused by long-term operation.In view of this defect,the paper proposes rectification measures and maintenance suggestions,which can be used for references in the follow-up maintenance,design and countermeasures of the anode reactor.