The EHV/UHV transmission lines on the same tower have high induced voltage and current due to the small spacing and short distance

which will directly affect the line maintenance

operation and selection of grounding switch equipment. Taking the 750 kV double circuit transmission line on the same tower from Lanzhou east to Qianxian as an example

we use ATP/EMPT electromagnetic transient simulation software to build the model of double circuit transmission line on the same tower and then analyze the effects of horizontal spacing between transmission lines

length of the running line

height of the grounding wire

soil resistivity and operating current on the induced voltage and current on the maintenance line and get the current sizes through the maintenance staff under various typical working conditions. The results show that: the induction voltage and the induced current on the maintenance line are inversely proportional to the horizontal spacing;length of the running line has a significant influence on the electromagnetic induction voltage and the static induction current on the maintenance line;height of the grounding wire has great influence on static induction voltage and electromagnetic induction component;the effect of soil resistivity on the induced voltage and current on the maintenance line can be neglected;the operating current impacts the electromagnetic induction voltage and the electromagnetic induction current significantly. When the grounding wires are connected to both sides of the maintenance position

the current through the maintenance personnel can reach to the grade of m A

and the safety of the personnel can not be fully guaranteed

so a security line needs to be added in the maintenance point to lower the current flowing through the human body to the microampere level and ensure the safety of the maintenance personnel.