When the tower overhead is struck by the lightning impulse, the lightning current flows into the earth through the impedance of tower and the grounding resistance, which heightens potential of the tower overhead and p...When the tower overhead is struck by the lightning impulse, the lightning current flows into the earth through the impedance of tower and the grounding resistance, which heightens potential of the tower overhead and possibly induces insulator flashover. Lighting rod arrester is used to shield the tower and provide another routine for lightning current, decreasing the potential of tower overhead. In this paper, the performance of a 500 kV lighting rod arrester is tested used in AC transmission system under the current impulse. Besides, the influence of the lightning rod arrester performance on the top potential of tower is also studied. The results show that, when the rod arrester is connected to the tower, the top potential of tower can be obviously limited under the lightning strike.展开更多
为满足光纤复合架空地线(OPGW)直流融冰的需要,同时解决环流损耗和易遭雷击断股等问题,须将OPGW接地方式由目前常用的逐塔接地改造为分段或全线绝缘、单点接地方式;OPGW经地线绝缘子及其并联放电间隙与杆塔相连。为此,提出了OPGW直流融...为满足光纤复合架空地线(OPGW)直流融冰的需要,同时解决环流损耗和易遭雷击断股等问题,须将OPGW接地方式由目前常用的逐塔接地改造为分段或全线绝缘、单点接地方式;OPGW经地线绝缘子及其并联放电间隙与杆塔相连。为此,提出了OPGW直流融冰绝缘化改造对并联放电间隙的电气要求,分别对正常运行时、地线直流融冰条件下和雷击情况下的并联放电间隙电气性能进行了详细的计算分析和试验研究。结果表明:并联放电间隙距离选择应满足感应电压和直流融冰电压的耐受要求,还应保证并联放电间隙在雷电过电压下可靠击穿;要满足工频感应电压的耐受要求,间隙距离可取20~100 mm;要满足直流融冰电压为-20 k V×(1±10%)的耐受要求,间隙距离应大于60 mm;考虑到间隙放电的分散性,间隙距离宜适当增大,推荐值为70~80 mm;70~80 mm间隙距离的雷电冲击放电电压一般不大于100 k V,线路遭受雷击时,地线绝缘子与并联放电间隙所承受的电压至少为885 k V,甚至高达数MV,并联放电间隙能可靠击穿,从而确保地线绝缘子的运行安全性。该研究结果可为OPGW直流融冰绝缘化改造提供理论支撑和数据支持。展开更多
文摘When the tower overhead is struck by the lightning impulse, the lightning current flows into the earth through the impedance of tower and the grounding resistance, which heightens potential of the tower overhead and possibly induces insulator flashover. Lighting rod arrester is used to shield the tower and provide another routine for lightning current, decreasing the potential of tower overhead. In this paper, the performance of a 500 kV lighting rod arrester is tested used in AC transmission system under the current impulse. Besides, the influence of the lightning rod arrester performance on the top potential of tower is also studied. The results show that, when the rod arrester is connected to the tower, the top potential of tower can be obviously limited under the lightning strike.
文摘为满足光纤复合架空地线(OPGW)直流融冰的需要,同时解决环流损耗和易遭雷击断股等问题,须将OPGW接地方式由目前常用的逐塔接地改造为分段或全线绝缘、单点接地方式;OPGW经地线绝缘子及其并联放电间隙与杆塔相连。为此,提出了OPGW直流融冰绝缘化改造对并联放电间隙的电气要求,分别对正常运行时、地线直流融冰条件下和雷击情况下的并联放电间隙电气性能进行了详细的计算分析和试验研究。结果表明:并联放电间隙距离选择应满足感应电压和直流融冰电压的耐受要求,还应保证并联放电间隙在雷电过电压下可靠击穿;要满足工频感应电压的耐受要求,间隙距离可取20~100 mm;要满足直流融冰电压为-20 k V×(1±10%)的耐受要求,间隙距离应大于60 mm;考虑到间隙放电的分散性,间隙距离宜适当增大,推荐值为70~80 mm;70~80 mm间隙距离的雷电冲击放电电压一般不大于100 k V,线路遭受雷击时,地线绝缘子与并联放电间隙所承受的电压至少为885 k V,甚至高达数MV,并联放电间隙能可靠击穿,从而确保地线绝缘子的运行安全性。该研究结果可为OPGW直流融冰绝缘化改造提供理论支撑和数据支持。
