Torsional Vibration Protection System

The increasing use of variable frequency drives (VFDs) and island mode power generation due to remotely located sites make these Oil and Gas industry plants vulnerable to sub-synchronous torsional interactions. These interactions can occur with synchronous generators supplying island-like power systems with large VFDs, but also in synchronous motor-driven turbomachinery, especially with increased nominal power and complexity of the drive train. The increasing number of site issues evidences the lack of suitable torsional vibration measurement systems. This paper describes applications of the TVPS, a device developed to address turbomachinery torsional vibration problems. The system answers the need for ruggedness and durability for long term monitoring and can be installed on any turbocompressor or turbogenerator unit without imposing additional requirements. TVPS applications experienced by the authors will be described in this paper, including coupling of the TVPS with an active torsional mode damping control successfully tested on an LNG production train.