Calculation on Electromagnetic Environment of UHVDC and EHVAC Transmission Lines Erected in a Common Corridor

In this paper the limits in the standards for power frequency electric field, total electric field, power frequency magnetic field, DC magnetic field, audible noise and radio interference are summarized, and a method to calculate and evaluate the superposed electromagnetic environment due to the erection of UHVDC and EHVAC transmission lines in common corridor is proposed. Taking the common corridor in Shanghai region where ±800 kV DC transmission line and multi-loop DC transmission lines of different voltage grade are erected for example, the hybrid electromagnetic environment, including total electric field, total magnetic field, audible noise and radio interference, is calculated and analyzed. The parallel approach distances among ±800 kV DC transmission line, 500 kV AC transmission line and 220 kV AC transmission line are put forward and the minimum clearance to ground of each transmission line is given, besides, the minimum range of buildings and dwelling houses to be dismantled which locate in the planned corridor is determined.