Ion trajectories and corona effects at converting one circuit of a double circuit AC line to DC

This paper considers a typical 220 kV Egyptian double circuit line, in which one circuit of a normal double circuit is converted to 220 kV bipolar DC line. Four different alternatives of circuit conversion are considered, Field patterns arc presented with and without AC voltage presence. Distortion of the DC patterns is investigated and analyzed. The lateral average radio interference and audible noise profiles due to one cycle of AC voltage phasor for each alternative arc computed and compared with the other alternatives to choose the optimum arrangement. The influence of AC circuit voltage on the average radio interference and audible noise under the line is discussed.