Characterisation of the damping performance of a Stockbridge damper from laboratory tests of an overhead high-voltage transmission line conductor

Abstract

This paper presents a study to evaluate the damping effectiveness of Stockbridge dampers on an overhead high-voltage transmission line conductor and their effects on estimating the corresponding fatigue lifetime. To increase the understanding of the dynamic behaviour of Stockbridge dampers, a test setup was designed and constructed to accommodate a segment of a conductor following the normative prescriptions of CIGRÉ. A classical modal identification was initially conducted to characterise the corresponding dynamic behaviour without and with an added Stockbridge damper. The Power Method was used to assess the conductor self-damping at different vibration amplitudes and excitation frequencies. Furthermore, a set of sensors was installed on the conductor, close to the anchorage, to simulate the VIBREC device and permit the analysis of the damper’s influence in estimating the conductor’s lifetime. Through the analysis of the database collected with the tests, it was possible to assess the dynamic properties of the conductor, identify the reduction of the vibration amplitudes enabled by the Stockbridge damper, and characterise the consequent increase in the conductor’s lifetime.