Noriyuki Hayashi

Analysis of 60 Hz magnetic fields near ground level in 187 kV switchyard of a 187/66 kV AC substation

To improve understanding of 60 Hz magnetic field characteristics in AC power substations, a numerical calculation of a 60 Hz magnetic field in the 187 kV switchyard of a 187/66 kV substation in service is conducted by using a simple analytical method. The magnetic field profiles near ground level are calculated for various current conditions, and described in terms of the contour maps of magnetic flux density. Effects of the line and bus current conditions, the bus phasing arrangement, and the line and bus geometrical configuration on the substation magnetic field profiles are also investigated. >

Analysis of magnetic field profiles in electric blanket users

A theoretical analysis is presented of the magnetic field produced by electric blankets that provide one of the strongest magnetic field exposures among the commonly encountered household sources of power frequency magnetic field. Comparisons between the calculated and measured magnetic fields show that the analytical method based on the Biot-Savart law gives reasonable prediction of magnetic-field exposures associated with an electric blanket use. Experiments with a saline cylinder show that power-frequency magnetic fields penetrate the human body with no significant perturbation, which means that an external current, i.e. a blanket heating element current, is the only source of the magnetic fields in the blanket users body. >