Iron Losses in Cable Supports and Members of Tunnels Adjacent to Large Power Transmission Cables

Iron losses in cable supports and members of tunnels in large power transmission were measured and analyzed by arranging cables in various configurations in tunnels of actual size and about 10 m long in order to study iron losses which come from cable supports and members of tunnels adjacent to large power transmission cables installed in tunnels. Cable supports used in the study were typically made of square hollow steel pipe and L-bar. A box culvert tunnel, a steel segment tunnel and a reinforced concrete segment tunnel, which are widely used as tunnels for large power transmission cables, were prepared for the measurement. Theoretical expressions for qualitatively evaluating iron losses in various cable supports and members of tunnels were derived, and their validity was confirmed by experiments.