In order to solve the problem of shortage land resources, 110 kV four-circuit transmission lines on the same tower has been widely used in some cities, which not only can improve the transmission capacity of unit corridor, but also can improve power supply reliability. Because of the strong coupling among the four-circuit transmission lines, when one-circuit of 110kV transmission line is outage and the other three are in normal working, the induced voltage and induced current in the maintenance line will endanger the safety of the maintenance person. In this paper, the influencing mechanism of the non-outage lines on the maintenance of outage lines was derived. According to the practical parameters of lines and tower, the simulation model of 110 kV four circuit transmission lines on the same tower was established by electromagnetic transient program (ATP).Taking the line length consideration, the induced voltage and induced current of maintenance line was calculated. Current of human body was analyzed in two kinds of maintenance ways. The results showed that electrostatic induction voltage is not affected by line length. The electrostatic induction current, the electromagnetic induction voltage and the electromagnetic induction current are proportional to line length. Maintenance method 1 without grounding line can't guarantee the safety of the maintenance staff, and under maintenance method 2 with grounding line, the body current level isμA, which can guarantee the safety of the maintenance staff.%为解决土地资源紧缺的问题,中国部分城市110 kV线路已广泛采用同塔四回的输电方式,不仅提高了单位走廊的输电容量还保证了供电可靠性.但线路线间耦合严重,三回正常运行线路会在停运检修线路上感应出电压、电流,影响作业人员的人身安全.从理论上推导感应电压和感应电流的产生机理,并根据实际线路、杆塔参数建立110 kV同塔四回输电线路的ATP仿真模型,计算线路长度对检修线路上感应电压分量和感应电流分量的影响,最后对比分析2种不同检修方式下的人体电流.研究结果表明:线路长度对静电感应电压的影响较小;静电感应电流、电磁感应电压和电磁感应电流与线路长度成正比;无保安线的检修方式无法保证检修人员的安全,而在挂接保安线下的人体电流只有μA级,可保证检修人员的安全.
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