Dynamic Behavior of Cable Systems with Spacers Following Ice Shedding

Ice accretion on cables of overhead transmission lines is a serious and frequently arising problem in cold regions. The accreted ice leads to heavy static load, while ice-shedding may result in high-amplitude vibrations which are usually associated with excessive transient dynamic forces. A widely used method to attenuate the vibration due to wind or ice-shedding, and reduce the resulting transient dynamic forces is the application of spacers between two, three or four conductors.

The dynamic behavior of systems of two, three and four conductors with spacers following ice-shedding from one subconductor is examined in the present study. Modal analysis is carried out, which calculates the first few natural frequencies and provides the damping performance of the system. Results are compared with those obtained for a single cable and for a system of two cables with a cross-tie which is often applied in cable-stayed bridges. A numerical model is also constructed using the finite element method. Simulations with the constructed model show how the resistance of cable systems against vibrations following ice-shedding increases with the application of spacers.