Semi-active control of forced oscillations in power transmission lines via optimum tuneable vibration absorbers: With review on linear dynamic aspects

• Hybrid model of the transmission line under an arbitrary number of absorbers.
• Design of tuneable vibration absorbers (TVAs) to suppress galloping vibrations.
• A sophisticated multi-loops algorithm for global optimization of TVAs׳ parameters.
• Optimum TVAs act efficiently in suppression of galloping & flutter vibrations.
• 2D/3D lookup diagrams for optimum selection of TVAs׳ parameters in industry.

Due to flexibility, relatively small weight and low energy-dissipative characteristics of cables, they are vulnerable to external excitations such as wind, wind–rain, earthquake and traffic loadings. Among them, galloping phenomenon is one of the most important sources of electrical/mechanical failures in power transmission lines. In this paper, tuneable vibration absorbers (TVAs) are used to suppress galloping forced vibrations (as a semi-active control approach). Using mode summation technique, mathematical model of the hybrid problem including the transmission line and an arbitrary number of absorbers is presented. Developing a sophisticated multi-loops optimization algorithm, best values of the absorbers׳ parameters (their location and stiffness, not necessarily symmetric) are found such that the transmission line deflection is minimized. Simulation results are presented in time and frequency domains. According to the results, designed TVAs act efficiently in suppressing galloping forced vibrations, especially under resonance conditions. Finally, global optimum design of TVAs is presented through a lookup diagram for a wide range of harmonic excitations. Since the optimal algorithm is developed in an extensive and general user-friendly manner, TVAs design can be accomplished for other industrial applications of flexible cables; under various excitations.