Magnetically induced swing movement of overhead power line conductors in a transition span subsequent to an initial fault

An initial electric fault can result in strong magnetic torque exerted on overhead power line conductors, which will make them swing and may bring them to close proximity or in contact with one another, causing a subsequent fault. Computer simulations have been developed for the analysis of the subsequent fault and presented in the authors’ earlier work for level spans and inclined spans that are both of uniform power line construction. However, in practice, a power line topology may require a transition from one power line structure to another. Such a required transition can be realized by a transition span. In this paper, we present a dynamic analysis of swing movement of power line conductors in a transition span subsequent to an initial fault, to track the smallest distance between the conductors, which is an important factor useful for predicting the probability of the subsequent fault. The analysis is much more complex than that for level spans and inclined spans. To address the complexity, we employ coordinate system transformations and establish a common coordinate system, then make use of it in the dynamic analysis. Sample numerical results are presented, analyzed, and checked with the energy conservation law requirement.