Theoretical and Experimental Study on Electromagnetic Induction From Power Line Against Multi-point Grounded Conductors

Electromagnetic induction between power lines and telecommunication cables has been studied since early 1900's [1]-[12], because such induced voltage may cause physical injury to service personnel, and malfunction of telecommunication equipment or quality degradation of telecommunications. On the other hand, induction against suspension wires that support overhead telecommunication cables has been studied less because its structure can be complicated and it is connected to grounds at multiple points. In this paper, we have studied induction phenomena against multiple point grounded conductors, theoretically and experimentally. Firstly, we replaced the induction model with an equivalent mesh circuit and calculated voltages at each grounded point. Secondly, we measured node voltage at each grounded point using a 1:1000 scale model to confirm accuracy of the calculation model for ideal and real conditions. From these results, the calculated results are in good agreement with the experimental results for ideal conditions. However, the experimental and calculated results of real conditions have some errors at the edge of the node voltage. Thus, we intend to improve the measurement setup and calculation model in our future work.