中波放送波による送電線への誘導電界の低減(架空地線を含む共振構造の場合)

抄録

It has been pointed out that a very strong electromagnetic field is induced occasionally along aerial power lines located near a medium wave (MW) broadcasting station, and the construction and the maintenance of power lines are sometimes endangered. We have presented a method to predict a dangerous span before the construction and the maintenance, and a use of a loading of appropriate inductor to decrease the induced field the case where the resonant loop is composed of three power lines, i.e., a top conductor, a middle conductor and a bottom conductor and part of towers.
In this paper, the effect of loading inductor for the case that the resonant loop includes a ground wire is presented. Since the ground wire is connected directly to the tower, the inductor can not be loaded into the ground wire. It is shown that the field strength in the vicinity of three power lines can be suppressed by loading the inductor to three power cables each. However, the field in the vicinity of the ground wire can not be suppressed significantly. Measured values of the field strength in the vicinity of the bottom conductor is presented to confirm the suppression effect.