Abstract
The electromagnetic induction interference from power line to communication line has increasingly become important problems. As the method to reduce the induced voltage, the shielded cable with aluminum sheath and iron tape has been mainly used. In order to increase screening effect of the shielded cable, the grounding resistance at the terminal of the cable must be low. But, recently, obtaining the low value of grounding resistance by usual construction method has become more difficult.
As a countermeasure against the above-mentioned problem, the method using the buried straight horizontal wire with vertical ground rod at the terminal of shielded cable is considered. However, so far, this method has been hardly investigated. Then, as a basic study of this method, authors carry out the theoretical analysis of screening effects for two models [in the case of model (a), the wire completely does not have infulence of induction from both the power line and shielded cable, and in the case of model (b), the wire has infulence of induction from both of them].
In this paper, the analyzing methods of screening effect for these two models are clarified. Furthermore, knowledges obtained from calculated results and the attention points in the practical earthing design of this method are clarified.
