In view of the rapid development of electric undertaking and a sharp increase of steel products consumption , the state development planning commission , the former state water resources and hydropower ministry and state energy ministry have been urging that the building of steel towers should be strictly controlled in the construction of transformer substations ; and warning that the need of the present 500kv power transmission and transformer trusses can hardly be satisfied by ordinary steel and concrete electric poles or prestressed concrete poles , which have endangered the operation and longevity of the high voltage transmitting line due to the common problem of cracks by gravity 随着电力工业建设的迅速发展，钢材的用量急剧增长，为此，国家计委，原水电部和能源部一再强调在输变电工程建设中，应从严掌握自立式铁塔的建设。然而，一般的钢筋混凝土电杆或与预应力混凝土电杆，较普遍地存在着纵向裂缝问题，严重影响了高压输电线路的安全运行及其使用寿命，已不能适应高压输电杆塔和变电构架的要求。
This thesis presents a single - terminal fault location technique that is used together with recloser . the technique takes advantage of reclosing of single - terminal recloser to eliminate the influence of the remote source impedance . a distributed parameter line model is used for the proposed algorithm , thus the technique can be used in hv transmission line 为了克服这一缺点，本文提出了与自动重合闸配合使用的单端故障测距方法，根据电力系统的运行特点，利用故障线路在试送电时自动重合闸的单端重合状态来消除对端系统的影响，测距算法建立在分布参数模型基础上，使其可应用于高压输电线路。
Prohibition of stalk burning in accordance with the requirements of the notice on enhancing environmental supervision on nature conservation , the environmental protection departments at various levels have strengthened the on - site enforcement inspection on the prohibiting the stalk burning in the zones prohibiting stalk burning , especially surrounding the airport , super highway , and along the railways and the high voltage electricity wires 秸秆禁烧工作深入推进各级环保部门按照国家环保总局《关于加强对自然生态保护进行环境监理的通知》的要求，加强了秸秆禁烧区内，特别是机场周围、高速公路、铁路沿线两侧和高压输电线路附近禁烧工作的现场执法检查。
The course of developing composite insulators and its large scale application in china are reviewed , and the statistics of domestic operating experience of composite insulators is given . the main failures which appear during the application of composite insulators , such as brittle fracture of rods , mechanical property , interface breakdown , creepage flashover , ageing performance and so on , are summarized and analyzed . the prospects of applying composite insulators in uhv transmission lines are forecasted 回顾了我国复合绝缘子的研制以及大规模应用的历史,对于国内复合绝缘子在使用中出现的一些主要问题,如芯棒脆断、机械性能、界面击穿、沿面闪络及老化性能等方面进行了统计、分析和总结,最后展望了复合绝缘子在特高压输电线路中的应用前景。
