南桥换流站阀塔光纤放电问题分析

Investigations of Fiber Discharge of Valve Tower in Nanqiao Converter Station

南桥站光纤改造工程项目为我国首个长期运行后的高压直流换流站更换换流阀光纤的项目。在初次安装阶段对空间电磁感应造成的影响考虑不足,造成VBE柜内多点放电。通过优化光纤表面的处理配方及在线涂覆工艺,解决光纤与护套的介电性能匹配问题,并采取等电位铜板、阻燃海绵和阀基电子设备(VBE)柜光纤固定夹板处接地措施后,运行情况良好,至今无任何放电和损坏发生。

The optical fiber reform project for Nanqiao converter station is the first project in China to replace the converter valve fiber for HVDC converter station after a long-term operation. During the initial installation phase, there was multiple-point discharge in VBE cabinets due to the ignorance of the impacts of space electro magnetic induction. The dielectric property matching problem betwee the optical fiber and its jacket is resolved by means of optimizating the surface treatment of fiber and on-line coating technology. The valve set is in good condition, and there is no recurrence of discharge and damage after the grounding measures by equipotential copperplate, fire-retardant foam and the optical fiber fixed-splints in VBE cabinets.