Mechanical Characteristics Relating to Fault Current in Bundle Conductors

Abstract

The flow of fault currents in bundled conductors induces an electromagnetic attraction between subconductors thereby the bus conductor system to an extremely high level of tension. This tention, which is the most important factor in designing the mechanical strength of the system, is determined by a large number of parameters-the magnitude of the fault current, the size and number of the subconductors, spacer interval, the spring of the structure, and so on. Full-scale 63 kA-class fault current tests were carried out on eight types of bus conductor used in 275 and 500kV subconductors, and measurements of fluctuation in tension were used to clarify the relationship between the various parameters and maximum tension at fault time.
A method was also devised for calculating maximum tension at fault time on the basis of the various parameters, and it has been applied in the mechanical strength design of bus conductor system.