Electromagnetic compatibility of high voltage transmission linesand the guidance of center pivot irrigation units with cornering systems

摘要

A study was carried out to determine if electromagnetic fields ofnhigh voltage transmission lines can interfere with electromagneticallynguided cornering systems associated with some center pivot irrigationnunits. Using electromagnetic susceptibility tests, it was found that 60nhertz magnetic fields of more than approximately 500 mG (milligauss) arenrequired to cause interference with the operation of one system. Thisnlevel is significantly higher than those found near most high voltagentransmission lines. It was also found that the magnetic fields atnharmonic frequencies and wideband fields due to corona on thentransmission line studied were insufficient to cause interference withncornering guidance systems. Observations of center pivot corneringnsystems operating properly near 345 kV transmission lines in Nebraska,nUSA, confirmed these results