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Abstract: In this paper an integrated approach for on-line induction motor fault detection and diagnosis is presented. The need to insure a continuous and safety operation for induction motors involves preventive maintenance procedures combined with fault diagnosis techniques. The proposed approach uses an automatic three step algorithm. Firstly, the induction motor stator currents are measured which will give typical patterns that can be used to identify the fault. Secondly, the eigenvectors/eigenvalues of the 3D current referential are computed. Finally the proposed algorithm will discern if the motor is healthy or not and report the extent of the fault. Furthermore this algorithm is able to identify distinct faults (stator winding faults or broken bars). The proposed approach was experimentally implemented and its performance verified on various types of working conditions. [Copyright &y& Elsevier]

Abstract: This paper studies the application of independent component analysis (ICA) and support vector machines (SVMs) to detect and diagnose of induction motor faults. The ICA is used for feature extraction and data reduction from original features. The principal components analysis is also applied in feature extraction process for comparison with ICA does. In this paper, the training of the SVMs is carried out using the sequential minimal optimization algorithm and the strategy of multi-class SVMs-based classification is applied to perform the faults identification. Also, the performance of classification process due to the choice of kernel function is presented to show the excellent of characteristic of kernel function. Various scenarios are examined using data sets of vibration and stator current signals from experiments, and the results are compared to get the best performance of classification process. [Copyright &y& Elsevier]

Abstract: The paper proposes an induction motor model for the study of harmonic load flow in balanced and unbalanced conditions. The parameters of this model are obtained from motor manufacturer data and the positive- and negative-sequence equivalent circuits of the single- and double-cage models. An approximate harmonic model based on motor manufacturer data only is also proposed. In addition, the paper includes manufacturer data and the calculated parameters of 36 induction motors of different rated powers. This database is used to analyze the proposed models. [Copyright &y& Elsevier]

Abstract: The developments in the power electronics field have lead to an ever-increasing use of static switching devices to control the torque and speed of ac motors. Invariably, the output voltage and current waveforms of these devices contain numerous harmonics and these harmonics have detrimental effects on the motor performance in form of derating and torque pulsation, especially at low speed. The order and magnitude of these harmonics depend on the design as well as nature of load being supplied. The extensive research has been underway for a long time in order to assess the effects these harmonics have on induction motor performance, and to investigate the various issues related to the use of induction motor to improve the drive performance and reduce the losses. This paper, therefore, presents a comprehensive review of research and developments in the induction motor operation with non-sinusoidal supply waveforms since its inception. Attempts are made to highlight the current and future issues involved in the development of induction motor drive technology to impart good dynamic stability with improved performance. A list of 167 research publications on the subject is also appended for a quick reference. [Copyright &y& Elsevier]

In this paper, an on-line efficiency optimization controller is proposed for induction motor drives after a detailed analysis of motor losses. The controller searches for a minimum motor drive input power by continuous variation of a control variable, resulting in a smooth system performance, which is not possible by the conventional stepwise change of the control variable. The search period is short. Thus, the controller can be applied effectively to applications with frequent changes of speed and load. Also, under the proposed controller, more energy saving is achieved. Extensive simulation is performed for the induction motor under the proposed and conventional efficiency optimization controllers. The results prove the superiority of the proposed controller. [Copyright &y& Elsevier]