Electric power high-voltage transmission lines: Design options, cost, and electric and magnetic field levels

摘要

This report provides background information about (1) the electric and magnetic fields (EMFs) of high-voltage transmission lines at typical voltages and line configurations and (2) typical transmission line costs to assist on alternatives in environmental documents. EMF strengths at 0 (+-) 200 ft from centerline were calculated for ac overhead lines, and for 345 and 230-kV ac underground line and for a (+-)450-kV dc overhead line. Compacting and height sensitivity factors were computed for the variation in EMFs when line conductors are moved closer or raised. Estimated costs for the lines are presented and discussed so that the impact of using alternative strategies for reducing EMF strengths and the implications of implementing the strategies can be better appreciated.