Abstract :
According to a recent report published by the British Intelligence Objectives Subcommittee, 550 yards of experimental 400-kv a-c line had been constructed in order to study corona loss in connection with a proposed 480-mile transmission of 600,000 kva from the Alps to Cologne. Tests showed that an arrangement of four conductors in parallel for each phase with 10-inch spacing between the steel-cored aluminium conductors would provide the maximum current-carrying capacity with the minimum of corona loss. Single-phase transformers with a 400-kv bushing out of one end and a 220-kv bushing for connection to a Petersen coil at the other, with lower voltage bushings at both ends, were to have been used. The air-blast circuit-breakers to be installed, rated at 1,000 amperes and 6,500 megavoltamperes interrupting capacity, had 14 breaks in series with capacitors for promoting equal voltage distribution between breaks.