Article ID Journal Published Year Pages File Type
559212 Mechanical Systems and Signal Processing 2015 16 Pages PDF
Abstract

•Hydraulic turbine instability detection using vibration measurements.•Cyclostationary analysis tools combined with order tracking.•Instability onset detection.•Use of kurtosis as a synthetic second order cyclostationarity index.•Effectiveness proven in an actual Kaplan turbine.

Hydraulic instabilities represent a critical problem for Francis and Kaplan turbines, reducing their useful life due to increase of fatigue on the components and cavitation phenomena. Whereas an exhaustive list of publications on computational fluid-dynamic models of hydraulic instability is available, the possibility of applying diagnostic techniques based on vibration measurements has not been investigated sufficiently, also because the appropriate sensors seldom equip hydro turbine units. The aim of this study is to fill this knowledge gap and to exploit fully, for this purpose, the potentiality of combining cyclostationary analysis tools, able to describe complex dynamics such as those of fluid-structure interactions, with order tracking procedures, allowing domain transformations and consequently the separation of synchronous and non-synchronous components. This paper will focus on experimental data obtained on a full-scale Kaplan turbine unit, operating in a real power plant, tackling the issues of adapting such diagnostic tools for the analysis of hydraulic instabilities and proposing techniques and methodologies for a highly automated condition monitoring system.

Related Topics
Physical Sciences and Engineering Computer Science Signal Processing
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