A 4th-order Kalman filter (KF) algorithm is implemented in a wireless sensor network (WSN) to estimate the temperatures of the stator windings, the rotor cage and the stator core of an asynchronous machine. The rotor speed, coolant air temperature, and the effective current and voltage are acquired by wireless transducer interface modules (WTIM) separately and are transmitted to a network capable application processor (NCAP) where the KF algorithm is implemented. The losses are calculated from the measurement and are processed together with the coolant air temperature by KF algorithm. As the...
The paper presents the automated diagnostic method of analog circuits combining supervised and unsupervised learning. The purpose of this sophisticated approach is to effectively distinguish easily identified states of the analyzed system from the more difficult ones. The latter are often related with existence of ambiguity groups, which create problems for the distinction of specific states. The proposed approach uses subsequently two algorithms. The first one extracts and learns to classify such “simple” training examples. The second one aims at the classification of more difficult ones....
Common reliability models rely usually on simple assumptions as to manage constant failure rates especially when electronic components are treated in the reliability block diagram. Nevertheless, more realistic modeling imply to deal with Weibull based hazard functions or even with more complex models. For oil and gas plants, and repairable systems in general, actually, it may happen to deal with nonlinear behavior of the failure intensity function. Multiple slope changes may occur due to long observation time and to restoration activities affecting the overall system performance and failure...
A short review is carried out about the uncertainty issues and requirements in environmental testing. Aspects concerning standards and operating procedures are considered and discussed, including considerations about test benches specifications and data analysis. Particular attention is paid on vibration tests and effects of different parameters. Some considerations are also presented considering the effect of data accuracy on reliability predictions.
Cyber-physical systems have extensive contact with the physical world. Usually during the development of these systems, the testing phase cannot be done efficiently or safely in the complete real environment, and therefore HIL (Hardware In the Loop) simulators are used. During HIL testing, diagnostic protocols are used very often to gather detailed information about the DUT’s (Device Under Test) internal state. Diagnostic protocols are very useful during testing, but they cause a significant load to the DUT. This paper introduces a novel approach to replace traditional diagnostic protocols...
This paper describes an analysis of impulse excitation method to determine initial parameters of lead-acid battery model. The initial model parameters are essential inputs of state predictors and significantly influence the precision of SoC and SoH tracking. Two types of Randles-model have been introduced where the model parameters were exploited from the impulse excited voltage response of a battery. Current impulse excitation approach is resourcesaving and convenient way to generate excitation signal by for example, switching relays especially in automotive systems. Switching a relay...
The ability of hydropower to adapt the electricity generation to the demand is necessary to integrate wind and solar energy to the grid. Nowadays hydropower turbines are required to work under harsher operating conditions and an advanced condition monitoring to detect damage is crucial. In this paper an improved method for condition monitoring procedure of Pelton turbines is introduced. A numerical model for the dynamic behavior of the machine has been built-up so that vibrations, deformations and stresses can be calculated for every operating condition. To improve the model, the data...
In this paper an integrated model environment is demonstrated which makes it capable to develop control, fault detection or state estimation algorithms for digitally controlled electric drives. Due to the mixed-signal platform it is possible to test and validate the developed methods. In this work a capacitor degradation phenomenon has been investigated which simulates a failure in a PI regulated Buck DC-DC converter.
High-sensitivity tools and methods of receiving diagnostic information are needed to detect low-energy defects. In this paper, the author proposes experimental results of the application of instantaneous angular acceleration for roller bearing fault detection (outer race fault, inner race fault and one ball fault). The experimental results show that defects are clearly visible in frequency spectrum of the angular acceleration. Also, the results can be used to build the defect patterns. In addition, the results show that frequency spectrum components of angular acceleration are significantly...
Embedded integer NARX (nonlinear autoregressive neural network with exogenous inputs) identification of the vibration experiments on knocking combustion of a Deutz MWM 8 cylinder large gas engine was carried. A measure of the degree of dependence of vibration and knocking reference values defined by the NARX recurrent neural network. A new identification is proposed based on the cross-correlation between the vibration signal and neural network error.