Ondřej Vítek

Detection of eccentricity and bearings fault using stray flux monitoring

The article describes the possibilities of employment of external magnetic field for detection of rotor eccentricity and for bearing fault diagnosis. Proposed method uses the magnetic flux density in proximity of induction motor as a diagnostic signal and it reaches the relatively high sensitivity in case of rotating air gap asymmetry represented by dynamic eccentricity. Since the bearing fault is the most frequent type of failure, the feasibility of applying this method is investigated. The results of experimental tests are introduced, including the motors with dynamic eccentricity and with artificially damaged bearing on the inner race. Both the stray flux and stator current are measured and compared in frequency domain.

Diagnosis of eccentricity and broken rotor bar related faults of induction motor by means of motor current signature analysis

Detection of faults in electrical motors is very important for avoiding unpredicted failures of the machines. Early detection and diagnosis of faults that may occur are desirable to ensure that operational effectiveness of an induction motor can be improved. In this paper, faults detection and classification using motor current signature analysis (MCSA) are presented. A series of simulations using the models of three phase cage induction motor is performed in different fault conditions, such as static, dynamic and mixed eccentricity and broken rotor bars. Designed models were implemented with the help of finite element method to provide data that makes it possible to diagnose presence of any type of faults, as well as to analyze obtained and calculated results. Models were designed on the basis of characteristics and parameters of real motor. The results are illustrated in the form of graphs and tables that make visible illustration for effectiveness of the used diagnosis method.

Detection and classification of faults in induction motor by means of motor current signature analysis and stray flux monitoring

In this paper the detection and classification of faults in induction motor using motor current signature analysis and monitoring of stray flux are presented. During the research motors with static, dynamic and mixed eccentricity were measured. The results were analyzed and compared with the data obtained from the simulated motor models. The behavior of sidebands of principal slot harmonics was examined. The results are presented in the form of graphs that illustrate the effectiveness and advantage of the method for diagnosis of the motor and detection of faults in it. Streszczenie. W artykule przedstawiono metodę detekcji I klasyfikacji defektów silników indukcyjnych na podstawie analizy prądu i strumienia rozprposzonego. Możliwe jest wykrywanie statycznych i dynamicznych ekcentryczności. Zmierzone parametry były porównywane z danymi otrzymanymi metoda symulacji. Detekcja i klasyfikacja defektów silnika indukcyjnego na podstawie analizy prądu i strumienia rozproszonego.

Analysis of high-speed induction motor

This paper deals with the analysis and design aspects of the high-speed induction machines. Unlike classical induction motor high-speed motor create many challenges in design. The challenges are discussed in the introduction. High-speed machines with solid rotors were design in ansoft Maxwell software. The study induction machine have nominal power 1500 W and synchronous rotating speed 40000 rpm. The first model is equipped with conductive cooper layer on the surface. The following models are equipped with axial slits. In the end the parameters of different machines were extract in Maxwell software.

Analysis of high speed squirrel cage induction motors

This paper deals with an analysis of three phase, two pole high speed induction machines. Our test motor was supplied from frequency converter and laboratory power supply with very low total harmonic distortion. Test bench was used to experimentally verify the results from simulation. The finite element model of induction motor was created in ANSYS Maxwell software. The model of frequency converter was created in ANSYS Simplorer and connect with ANSYS Maxwell model due to their co-simulation.

Analysis of induction motor faults by means of monitoring the current and magnetic flux density spectrums

In this paper the analysis of presence of faults in squirrel-cage induction motor using motor current signature analysis as well as monitoring of behavior of stray flux is presented. There were measured 6-pole motors with static, dynamic and mixed eccentricity. Measurement and analyzed results were compared with data obtained from the simulation and measurement of the 4-pole induction motor. The behavior of the sidebands of principal slot harmonics were examined. The illustration of effectiveness and practical benefits of use of these types of diagnosis is presented in the form of the graphs and tables.

Brushless alternator in automotive applications

This paper deals with reliability problems of common types of generators in hard conditions. It shows possibilities of construction changes that should increase the machine reliability. This contribution is dedicated to the study of brushless alternator for automotive industry. There are described problems with usage of common types of alternators and main benefits and disadvantages of several types of brushless alternators.

Virtual laboratory of DC machine and Automotive electrical engineering

This paper describes distance laboratory for automotive electrical engineering. Designed system allows system identification and parameter tuning Learning objectives are clearly defined and their verification is included too. Designed distance laboratory provides the user with a practical experience in Power Electronic and Motion Control education.