algorithm achieves tight estimates of the energy of irregular or aperiodic oscillations from records of interval or fuzzy-valued
signals. Fuzzy signals are given a possibilistic interpretation as families of nested confidence intervals. In this context,
some types of Supervisory Control And Data Analysis (SCADA) records, where the minimum, mean and maximum values of the signal
between two scans are logged, are regarded as fuzzy constrains of the values of the sampled signal. The generalized SSA of
these records produces a set of interval-valued or fuzzy coefficients, that bound the spectral transform of the SCADA data.
Furthermore, these bounds are compared to the expected energy of AR(1) red noise, and the irrelevant components are discarded.
This comparison is accomplished using statistical tests for low quality data, that are in turn consistent with the possibilistic
interpretation of a fuzzy signal mentioned before. Generalized SSA has been applied to solve a real world problem, with SCADA
data taken from 40 turbines in a Spanish wind farm. It was found that certain oscillations in the pressure at the hydraulic
circuit of the tip brakes are correlated to long term damages in the windmill gear, showing that this new technique is useful
as a failure indicator in the predictive maintenance of windmills.
- Content Type Journal Article
- Category Focus
- Pages 1-14
- DOI 10.1007/s00500-011-0767-3
- Authors
- Luciano Sánchez, Computer Science Department, University of Oviedo, Campus de Viesques, 33071 Gijón, Asturias, Spain
- Inés Couso, Facultad de Ciencias, Statistics Department, University of Oviedo, 33071 Oviedo, Asturias, Spain
- Journal Soft Computing – A Fusion of Foundations, Methodologies and Applications
- Online ISSN 1433-7479
- Print ISSN 1432-7643