Upgrading the Romanian 400 kV lines with 2 and 3 subconductors per phase to reduce the risk of galloping occurance and the galloping amplitudes by the installation of torsional dampers and detuners, live-line procedures

The concept of the damping pendulum as torsional damper and detuner (TDD) was created and reported in 1993 by its authors led by Prof. Jean-Louis Lilien from University of Liege-Belgium. Several versions were designed, tested and even used in some minor projects, demonstrating their high capacity to solve the risk of the overhead line conductor galloping with usual frequencies in the range 0.4-0.6 Hz. The parameter describing the damping performance is the transfer function with values in the range 1.5-2.5 in the case of the previous versions. The new version transfer function came to 3.0, the best met value till now. A description of the pendulum parts, tests carried out and the final design are presented. The pendulum can be easy mounted in live-line conditions.