This paper presents bushing condition monitoring frameworks that use multi-layer perceptrons (MLP), radial basis functions (RBF) and support vector machines (SVM) classifiers. The first level of the framework determines if the bushing is faulty or not while the second level determines the type of fault. The diagnostic gases in the bushings are analyzed using the dissolve gas analysis. MLP gives...

The analytical modelling of a condition monitoring for a system which is subject to degradation over time is considered. The system condition can be observed at discrete times by means of imperfect inspections. In addition to the critical threshold, for each time point of inspection a replacement threshold is introduced. The decision rule when checking system suitability for use in the upcoming...

In time-series analysis it is often assumed that observed data can be modelled as being derived from a number of regimes of dynamics, as e.g. in a Switching Kalman Filter (SKF) [8, 2]. However, it may not be possible to model all of the regimes, and in this case it can be useful to represent explicitly a ‘novel’ regime. We apply this idea to the Factorial Switching Kalman Filter (FSKF) by intro...

Part production requires constant monitoring to assure the effective manufacturing of high-quality components. The choice of monitoring methods can become a crucial factor in the decisions made during and prior to manufacturing. In an ideal world, designers and manufacturers will work together to interpret manufacturing and part data to assure the elimination of faults in manufacturing. However...

This paper concerns the analysis of stationary complex-valued signals, and its application to the condition monitoring field. More particularly, it is confirmed that usual tools such as correlation function or power spectrum are insufficient to entirely describe the statistical and geometrical properties of complex-valued signals. In that case, additional time and spectral domain quantities, na...

Wind energy is presently the fastest growing renewable energy source in the world. However, the industry still experiences premature turbine component failures, which lead to increased operation and maintenance (O&M) costs and subsequently, increased cost of energy (COE). To make wind power more competitive, it is necessary to reduce turbine downtime and increase reliability. Condition monitori...

During the last three decades, there have been many new developments in condition monitoring (CM) of high voltage equipment in electrical power systems. Hundreds of new instruments are in use around the world. Enormous quantities of CM data are collected from on-line and off-line tests every day. Now it might be the right time to ask “Are we using CM instruments wisely?” In fact, one of the pro...

Induction machines play a vital role in industry and there is a strong demand for their reliable and safe operation. They are generally reliable but eventually do wear out. Faults and failures of induction machines can lead to excessive downtimes and generate large losses in terms of maintenance and lost revenues, and this motivates the examination of on-line condition monitoring. The major dif...

Machinery maintenance accounts for a large proportion of plant operating costs. Compared with the conventional scheduled maintenance strategy which is to stop the machine at pre-determined intervals, modern condition-based maintenance strategy stops the machine only before there is evidence of impending failure. With the development of cheaper sensors, more and more sensors are designed for mac...

Received Sep 13, 2017 Revised Nov 13, 2017 Accepted Nov 21, 2017 The necessity to have reliable and quality power distribution is increasing, and hence there is great scope for research on automation of distribution system. There are signs of increased research in the work on condition monitoring of insulators during the last few decades. The possible failures can be predicted before they actua...