兴安直流系统分散接地方式替代专用极址探讨

Discussion on Distributed Ground System Substituting Special Pole in Xing-An HVDC Project

对多起兴安直流双极闭锁故障的研究显示,兴安直流输电线路同杆架设直流极线和接地极线的线路较长,雷电绕击极线时在接地极线感应过电压,存在着双极闭锁的潜在风险。进一步研究发现,如果将兴安直流线路广东侧接地极同杆并架段所有杆塔(极址10 km范围绝缘架空地线段仍然保持绝缘)用并沟线夹完全接地,可以构建一个新的分散式大型接地系统,不仅可以解决不平衡电流问题,而且大大降低了直流系统单极运行的电能损耗,同时对直流线路本身的防雷也有积极意义。接地系统形成后,鱼龙岭极址的功能被淡化,保护了鱼龙岭地区生态。在此基础上,对新建工程分散接地设置方式提出优化方案。

Detail analysis on several Xing-An HVDC bipolar block failures reveals that there is potential risk of bipolar block to the HVDC system due to the configuration of the same tower for both DC transmission line and earthing electrode line.Because lightning strike DC transmission line brings on earthing electrode line＇s faradism.Further study finds out that if the Guangdong side of both DC transmission line and earthing electrode line towers are grounded completely with parallel clamps,you can construct a new large-scale distributed ground system.This system not only solve the problem of unbalanced current,but also greatly reduces the power consumption of DC system under unipolar operation,and has positive impact on the DC circuit itself anti-lightning at the same time.After the ground system is completed,appropriative pole＇s functions have been weakened,the protection of the ecological appropriative pole.