IMPACT OF ELECTROMAGNETIC-FIELD MANAGEMENT ON THE DESIGN OF 500 KV TRANSMISSION-LINES

The electric and magnetic field (EMF) issue has become an area of incr easing public concern. There is a heightened sensitivity among the pub lic to the siting and construction of new, and the upgrading of existi ng electric facilities. There is substantial scientific uncertainty an d no widespread agreement among scientists as to how the presently ava ilable information regarding the possible health effects of electric a nd magnetic fields should be interpreted. Animal and epidemiological s tudies are inconclusive on whether exposure to EMF can cause human hea lth effects. Minimizing electric and magnetic field strength is one of the many factors to consider in the planning and design of a transmis sion system. It must be considered along with other issues such as saf ety, environmental concerns, reliability, insulation and electrical cl earance requirements, aesthetics, cost, operations and maintenance. Th e field reduction techniques described in this paper are proven method s, and the new techniques are explained thoroughly and incorporated ta king into consideration the percentage field reduction, maintenance, a nd operational reliability. The constraints for electric and magnetic field reduction by line compaction and optimization of bundles configu ration are studied taking into consideration the international accepte d minimum clearances. The importance of the phase configuration and se quence is also demonstrated. Novel-field cancellation methods are pres ented. Systematic comparisons of the effectiveness of different line d esigns in reducing the EMF are included. (C) 1997 Elsevier Science S.A .