Geomagnetic and geoelectric field disturbance produced by a substation −Case study of Yasato Substation−
Koike, K., Tokumoto, T., Nakajima, S., Owada, T., Ookawa, T. & Hasegawa, H.
Abstract
Yasato Substation was built at a location 1.4 km east-northeast of Kakioka Magnetic Observatory from September 2002 to May 2003 by Tokyo Electric Power Company. Generally, there was concern that the substation facility would disturb the magnetic field and earth current, so we performed observation of the magnetic field and earth current around the substation to investigate magnetic and electric influences quantitatively. The following findings were confirmed.
1.Although no electric signals produced by Yasato Substation were detected, magnetic signals of several nT were observed near the substation (at about 40 m distance), but these were not observed at Kakioka Magnetic Observatory 1.4 km away from the substation.
2.A proton procession magnetometer shows incorrect measurement values within several tens of meters of an electric feeder line. A high voltage (66 kV) substation facility near a magnetic observatory would generate serious difficulties in observatoin.
3.The amount of magnetic disturbance produced by the magnetic material of a substation or power pylon falls to about 0.1 nT outside a radius of about 400 to 500 m. The calculated magnetic disturbance is less than 0.01 nT, which is negligible, at Kakioka Magnetic Obseratory about 1.4 km away from these facilities.
