112 Romanian Experience with Antigalloping Devices: Technical and Financial Approach G. A. FLOREA, E. MATEESCU, L. LIPAN. S. TIBULIAC, M. VAJU, D. BALACI, C. BACIU Power& Lighting Tehnorob S. A., Gopa Intec S. A., University Politehnica Bucharest, C. N. Transelectrica S. A. ROMANIA SUMMARY 47 years ago the first major occurrences of conductors galloping were observed in Romania on a 400 kV transmission line. Major damages attributed to galloping were reported later on, but mainly from 1990’s . The galloping phenomenon is described and the meteorological conditions favoring it are also detailed. The main antigalloping devices being nowadays in use worldwide are shortly analyzed and the general description of the most used ones is presented, too. So, the torsional damper and detuner pendulums and the interphase spacers are presented. The TDD pendulum concept was initially developed in Liege University (Belgium) in 1980’s and was improved later on for the industrial use. More than a thousand of such pendulums were manufactured, tested and installed on 4 lines of 400 kV single circuit in Romania, starting from 2013. A comparison between the pendulum and the interphase spacers is presented taking into account the technical considerations of the galloping amplitude reductions, the dynamic load impacts on the line structural elements and the device end of life periods. From the financial point of view the comparison covers the initial costs of the devices, the total cost of the investment and the maintenance costs, also. From both the technical and economical points of view the conclusions are clear: the optimum device to be applied to the overhead lines with bundled phases composed by 2 or 3 subconductors per phase is the torsional detuning and damping pendulum: - life expectancy is double compared to the interphase spacers; - investments costs are about 60- 70% of those implied by interphase spacers; - maintenance expenses as yearly averaged are about the same; - galloping amplitude decreasing is 90- 92% compared to 15- 50% for interphase spacers; - damping transfer function values better in the case of TDD compared to the interphase spacers, not only the initial ones but after 2 and 5 years of operation, too. KEYWORDS Power Transmission – Overhead Line – Conductor – Galloping – Protection –Pendulum georgeflorea@tehnorob.ro