Hybrid Nutation Damper for Controlling Galloping Power Lines

A novel add-on device, called a hybrid nutation damper (HND), is proposed to control galloping on both single and bundled conductors of overhead power lines. An HND employs a nutation damper (also called a tuned liquid damper) as an energy dissipator, and a tuned mass damper as the mechanism to transfer a conductor's plunge motion into a nutation damper's rotational motion. An HND is in principle effective for any type of galloping. It is particularly effective for a plunge galloping-the one most often observed in the field and existing control devices have difficulty handling. An HND is simplified as an equivalent two degrees-of-freedom model and is then incorporated into existing three degrees-of-freedom based, galloping software. A two-tiered procedure is established to optimize an HND's performance. Numerical examples show that an HND is invariably very promising in controlling galloping