1998 Volume 118 Issue 4 Pages 437-443
Introduction of higher voltage and larger capacity power transmission lines and the power apparatus has recently changed the electromagnetic environment around them, and thus the precise measurement and analysis become more important. Magnetic field distribution around power transmission line is very complicated because of the three-phase current condition, the three-dimensional configuration of conductors and the existence of ferromagnetic structure, for example. Moreover, little attempt has been ever tried to measure the power-line current and the magnetic field distribution, thus, the effect of unbalanced current, harmonic content have not been fully understood.
From these backgrounds, we simultaneously measured the magnetic field distribution and the current of power lines. It was clarified that the unbalanced current produced the unbalanced distribution of magnetic field and, in this paper, the contribution was quantitatively analyzed.