“Restricting wind induced vibrations of transmission line for uninterrupted power supply using Vibration Dampers”
The interruption of electricity due to failure of transmission lines can trigger social and economic calamities. The cables of the transmission lines are prone to Aeolian vibrations and oscillations. The abatement of the severity of Aeolian vibration is a crucial issue hence, to suppress these vibration disturbances to a safe limit -‘Vibration Dampers’ are required to be installed in overhead transmission lines.
Stockbridge Damper: They are designed so that their mechanical impedance matches the optimum damper impedance determined for the cable to be protected as closely as possible. Basically, it is a tuned mass damper and can be used for wide range of frequencies. It is widely used as a preventive measure against vortex induced vibrations.
Spiral Impact Damper: It consists of a PVC rod installed over conductors vibrating at higher frequencies which dissipates energy and also induces more acceleration for a given displacement. One of the attributes of this damper is that two units can be installed with the conductors and can be used for a wide range of frequency variations.
Spacer Damper: These dampers are designed for suppressing the sub-span oscillation in bundled conductors as well as can be used as a remedy against Aeolian vibration. Even after experiencing severe loads under the influence of ice and wind, it restores the bundle to normal posture. We have developed in-house Twin, Quad and Hex spacer dampers. Quad and Hex have been successfully tested at Hydro-Quebec, Canada while Twin has been analytically verified using software tools.
By- Sushri Mukherjee, Sumana Chattaraj, Madhuri Kumari Shaw, P. Barua, D. Prasad