摘要
输电线路覆冰严重影响电力系统安全运行,由于架空地线的悬挂点高于相导线,所处的环境温度低,同时没有运行电流等原因,在相同覆冰段下比其它导线覆冰更为严重。目前,大电流融冰技术是防治导、地线覆冰的最为有效的措施之一,由于架空地线的特殊结构,在开展大电流融冰之前,需对其进行绝缘化改造,但地线在绝缘化改造后的感应电压不仅影响到输电线路的安全运行和防雷效果,也是融冰电压和并联间隙选取的关键因素。笔者以500 kV同塔双回架空输电线路为例,在ATP-EMTP中建立了仿真模型,分析了架空地线与OPWG绝缘化改造后感应电压的分布规律。结果表明:单点接地方式下架空地线绝缘分段长度控制在5 km左右,架空地线感应电压可以处在安全范围;单点接地时将接地点位置设置在分段中点能够使感应电压降低约50%;对传输线相导线进行换位,通过影响导线与架空地线间的电磁感应,可以起到抑制感应电压的作用。研究结果可为输电线路架空地线的绝缘改造设计提供参考。
Atmospheric ice accumulation on the transmission line seriously affects the safe operation of the power system. Because of high suspension point,no current,low operating temperature,overhead ground wires bear severer atmospheric ice accumulation than other transmission lines in the same ice-covered area. At present,the high-current ice-melting technology is one of the most effective measures to prevent the grounding wires from icing. Due to the special structure of the overhead ground wires,it is necessary to conduct insulation reconstruction before the high-current ice-melting is carried out. However,the induced voltage of overhead ground wires after the insulation reconstruction not only affects the safe operation of the transmission lines and the lightning protection effect,but also a critical factor in the selection of the ice-melting voltage and the parallel discharge clearance. The author will take a 500 k V double-circuit overhead transmission line on the same tower as an example,establishing a simulation model in ATP-EMTP to analyze the distribution regularity of induced voltage of OPGW and ground wires after the insulation reconstruction. The results show that: the length of the insulation ground segment of the overhead ground wires of single point grounding should be limited to 5 km or so,so that the induced voltage of the overhead ground wire can be in the safe range. Setting the grounding point at the midpoint of the segment when grounding at a single point can reduce approximately 50% induced voltage;The transposition of the transmission line can suppress the induced voltage by affecting the electromagnetic induction between the conductor and the overhead ground wires. The simulation results can provide reference for the insulation reconstruction of the overhead ground wires.
作者
邓元实
范松海
龚奕宇
谢正军
毕茂强
杨俊伟
DENG Yuanshi;FAN Songhai;GONG Yiyu;XIE Zhengjun;BI Maoqiang;YANG Junwei(Electric Power Research Institute of Sichuan Power Electric Corporation of State Grid,Chengdu 610072,China;Sichuan Power Electric Corporation of State Grid,Chengdu 610072,China;College of Electronic Information and Automation,Chongqing University of Technology,Chongqing 400054,China)
出处
《电瓷避雷器》
CAS
北大核心
2020年第6期15-21,共7页
Insulators and Surge Arresters
基金
国网四川省电力公司科技项目“高海拔地区输电线路状态监测装置供能及信号传输技术研究”(编号:521997170016)。
关键词
OPGW
绝缘化改造
感应电压
覆冰
融冰
OPGW
insulation reconstruction
induced voltage
icing
de-icing
