Modeling the structural dynamic response of overhead transmission lines

Static analysis forms the basis of calculations in structural design of overhead power lines. The environmental loads considered in design can be assumed static (icing) or quasi-static (idealized steady wind). However, dynamic analysis is necessary to predict line transient response to shock loads such as those induced by the sudden failure of components or sudden ice-shedding effects on the conductors. This paper summarizes a macroscopic modeling approach to line dynamic analysis where emphasis is put on capturing the salient features of the propagation of such shock loads in a line section. The approach is illustrated with a case study of a line section having suffered two tower failures due to conductor breakages during an ice storm. The cable dynamics model proposed has been applied successfully to several examples, using the commercial software ADINA.