An investigation into the condition monitoring strategy for a large reversible Francis Pump-Turbine

The authors were asked to devise a strategy for eliciting information from the current vibration monitoring system, which could be utilised in a condition monitoring strategy for the reversible Francis Pump-Turbines located at Dinorwig Power Station, one of the world's largest hydro-electric pump storage schemes. The station consists of six 300MW machines, with each of the 520 tonne assemblies being suspended via a support bracket and a set of oil lubricated thrust bearing pads. Dinorwig performs a critical role in the UK National Grid system due to its ability to provide almost instantaneous power. Each of the machines must operate under an arduous regime in comparison with thermal base-load units, with each unit performing up to twenty-five mode change sequences per day. The information routinely available to Operations Staff provides only a general indication of machine condition. It was found during the study that the installed transducers and signal processing capabilities were capable of producing data series, which can provide considerable useful information, However, this required the introduction of an additional data logger. This paper summaries the results of the preliminary study, outlining the techniques used and describes a number of options for further development in the future.