Development and application of software for the analysis of magnetically induced subsequent fault (MISFault)

As an initial electric fault occurs, the fault current would result in a strong magnetic force and torque exerted on the power line conductors. The rotational magnetic torque, in turn, would make the power lines with sags swing and may bring them to close proximity or in contact with one another, causing a subsequent fault. For the analysis of the magnetically induced subsequent fault (MISFault), software has been developed as the end product of a multi-year research project sponsored by Duke Energy Company. The software is capable of predicting the smallest distance between the power line conductors during their swing procedure, from which one can predict the probability of the magnetically induced subsequent fault; and determine the allowed span length range from consideration of eliminating the subsequent fault, which is anticipated to be useful for a utility in long span design. The software has been tested and the accuracy of its computation results has been validated by verifying that the energy conservation law requirement is well satisfied. The MISFault software is being used by Duke Energy Company. It is user friendly and is expected to be useful to a utility for eliminating the magnetically induced subsequent fault.