CST12 - High Vibration at Low Speed on a 25MW Turbogenerator System - Root Cause Investigation

Abstract

During the comissioning and filed-tests of the turbogeneration system of an oil platform, low speed high vibration levels were observed on the generator shaft and other neighbouring vibration sensors. The vibration was synchronous and seemed not to be influenced by alignment conditions. The final conclusion revealed that the problem resided in improper mating of generator coupling flange faces. A complete description of the investigation process, diagnostics and solution implementation will be presented along with recommended practices in order to avoid the same problem in other similar systems.