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- Induction motors (3)
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- Broken bar (1)
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- Heating (1)
- Impact ionization (1)
- Induction motor (1)
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- Interturn short circuit (1)
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Articles 1 - 17 of 17
Full-Text Articles in Computer Engineering
Inter-Turn Fault Diagnosis In Induction Motors Using The Pendulous Oscillation Phenomenon, Behrooz Mirafzal, Richard J. Povinelli, Nabeel Demerdash
Inter-Turn Fault Diagnosis In Induction Motors Using The Pendulous Oscillation Phenomenon, Behrooz Mirafzal, Richard J. Povinelli, Nabeel Demerdash
Electrical and Computer Engineering Faculty Research and Publications
A robust interturn fault diagnostic approach based on the concept of magnetic field pendulous oscillation, which occurs in induction motors under faulty conditions, is introduced in this paper. This approach enables one to distinguish and classify an unbalanced voltage power supply and machine manufacturing/construction imperfections from an interturn fault. The experimental results for the two case studies of a set of 5-hp and 2-hp induction motors verify the validity of the proposed approach. Moreover, it can be concluded from the experimental results that if the circulating current level in the shorted loop increases beyond the phase current level, an interturn …
Synergistic Use Of Compound Properties And Docking Scores In Neural Network Modeling Of Cyp2d6 Binding: Predicting Affinity And Conformational Sampling, Peter S. Bazeley, Sridevi Prithivi, Craig Struble, Richard J. Povinelli, Daniel S. Sem
Synergistic Use Of Compound Properties And Docking Scores In Neural Network Modeling Of Cyp2d6 Binding: Predicting Affinity And Conformational Sampling, Peter S. Bazeley, Sridevi Prithivi, Craig Struble, Richard J. Povinelli, Daniel S. Sem
Electrical and Computer Engineering Faculty Research and Publications
Cytochrome P450 2D6 (CYP2D6) is used to develop an approach for predicting affinity and relevant binding conformation(s) for highly flexible binding sites. The approach combines the use of docking scores and compound properties as attributes in building a neural network (NN) model. It begins by identifying segments of CYP2D6 that are important for binding specificity, based on structural variability among diverse CYP enzymes. A family of distinct, low-energy conformations of CYP2D6 are generated using simulated annealing (SA) and a collection of 82 compounds with known CYP2D6 affinities are docked. Interestingly, docking poses are observed on the backside of the heme …
Sub-Banded Reconstructed Phase Spaces For Speech Recognition, Kevin M Indrebo, Richard J. Povinelli, Michael T. Johnson
Sub-Banded Reconstructed Phase Spaces For Speech Recognition, Kevin M Indrebo, Richard J. Povinelli, Michael T. Johnson
Electrical and Computer Engineering Faculty Research and Publications
A novel method combining filter banks and reconstructed phase spaces is proposed for the modeling and classification of speech. Reconstructed phase spaces, which are based on dynamical systems theory, have advantages over spectral-based analysis methods in that they can capture nonlinear or higher-order statistics. Recent work has shown that the natural measure of a reconstructed phase space can be used for modeling and classification of phonemes. In this work, sub-banding of speech, which has been examined for recognition of noise-corrupted speech, is studied in combination with phase space reconstruction. This sub-banding, which is motivated by empirical psychoacoustical studies, is shown …
Soft-Started Induction Motor Modeling And Heating Issues For Different Starting Profiles Using A Flux Linkage Abc Frame Of Reference, M. G. Solveson, Behrooz Mirafzal, Nabeel Demerdash
Soft-Started Induction Motor Modeling And Heating Issues For Different Starting Profiles Using A Flux Linkage Abc Frame Of Reference, M. G. Solveson, Behrooz Mirafzal, Nabeel Demerdash
Electrical and Computer Engineering Faculty Research and Publications
In order to mitigate the adverse effects of starting torque transients and high inrush currents in induction motors, a popular method is to use electronically controlled soft-starting voltages utilizing series-connected silicon-controlled rectifiers (SCRs). Investigation of semioptimum soft-starting voltage profiles was implemented using a flux linkage ABC frame of reference model of a soft-started three-phase induction motor. A state-space model of the soft-starter thyristor switching sequence for the motor and load was developed and implemented in a time-domain simulation to examine winding heating and shaft stress issues for different starting profiles. Simulation results of line starts and soft starts were compared …
Statistical Models Of Reconstructed Phase Spaces For Signal Classification, Richard J. Povinelli, Michael T. Johnson, Andrew C. Lindgren, Felice M. Roberts, Jinjin Ye
Statistical Models Of Reconstructed Phase Spaces For Signal Classification, Richard J. Povinelli, Michael T. Johnson, Andrew C. Lindgren, Felice M. Roberts, Jinjin Ye
Electrical and Computer Engineering Faculty Research and Publications
This paper introduces a novel approach to the analysis and classification of time series signals using statistical models of reconstructed phase spaces. With sufficient dimension, such reconstructed phase spaces are, with probability one, guaranteed to be topologically equivalent to the state dynamics of the generating system, and, therefore, may contain information that is absent in analysis and classification methods rooted in linear assumptions. Parametric and nonparametric distributions are introduced as statistical representations over the multidimensional reconstructed phase space, with classification accomplished through methods such as Bayes maximum likelihood and artificial neural networks (ANNs). The technique is demonstrated on heart arrhythmia …
Microswitches With Sputtered Au, Aupd,Au-On-Aupt, And Auptcu Alloy Electric Contacts, Ronald A. Coutu Jr., J. R. Reid, R. Cortez, R. E. Strawser, P. E. Kladitis
Microswitches With Sputtered Au, Aupd,Au-On-Aupt, And Auptcu Alloy Electric Contacts, Ronald A. Coutu Jr., J. R. Reid, R. Cortez, R. E. Strawser, P. E. Kladitis
Electrical and Computer Engineering Faculty Research and Publications
This paper is the first to report on a new analytic model for predicting microcontact resistance and the design, fabrication, and testing of microelectromechanical systems (MEMS) metal contact switches with sputtered bimetallic (i.e., gold (Au)-on-Au-platinum (Pt), (Au-on-Au-(6.3at%)Pt)), binary alloy (i.e., Au-palladium (Pd), (Au-(3.7at%)Pd)), and ternary alloy (i.e., Au-Pt-copper (Cu), (Au-(5.0at%)Pt-(0.5at%)Cu)) electric contacts. The microswitches with bimetallic and binary alloy contacts resulted in contact resistance values between 1-2Omega. Preliminary reliability testing indicates a 3times increase in switching lifetime when compared to microswitches with sputtered Au electric contacts. The ternary alloy exhibited approximately a 6times increase in switch lifetime with contact resistance …
An Lmi Approach To Discrete-Time Observer Design With Stochastic Resilience, Edwin E. Yaz, Chung Seop Jeong, Yvonne I. Yaz
An Lmi Approach To Discrete-Time Observer Design With Stochastic Resilience, Edwin E. Yaz, Chung Seop Jeong, Yvonne I. Yaz
Electrical and Computer Engineering Faculty Research and Publications
Much of the recent work on robust control or observer design has focused on preservation of stability of the controlled system or the convergence of the observer in the presence of parameter perturbations in the plant or the measurement model. The present work addresses the important problem of stochastic resilience or non-fragility of a discrete-time Luenberger observer which is the maintenance of convergence and/or performance when the observer is erroneously implemented possibly due to computational errors i.e. round off errors in digital implementation or sensor errors, etc. A common linear matrix inequality framework is presented to address the stochastic resilient …
Fast Thermal Profiling Of Power Semiconductor Devices Using Fourier Techniques, J. J. Nelson, G. Venkataramanan, Ayman M. El-Refaie
Fast Thermal Profiling Of Power Semiconductor Devices Using Fourier Techniques, J. J. Nelson, G. Venkataramanan, Ayman M. El-Refaie
Electrical and Computer Engineering Faculty Research and Publications
Accurate prediction of temperature variation of power semiconductor devices in power electronic circuits is important to obtain optimum designs and estimate reliability levels. Temperature estimation of power electronic devices has generally been performed using transient thermal equivalent circuits. In the presence of varying load cycles, it has been typical to resort to a time-domain electrical simulation tool such as P-Spice or SABER to obtain a time series of the temperature profiles. However, for complex and periodic load cycles, time-series simulation is time consuming. In this paper, a fast Fourier analysis-based approach is presented for obtaining temperature profiles for power semiconductors. …
Analysis Of Surface Permanent Magnet Machines With Fractional-Slot Concentrated Windings, Ayman M. El-Refaie, Thomas M. Jahns, Donald W. Novotny
Analysis Of Surface Permanent Magnet Machines With Fractional-Slot Concentrated Windings, Ayman M. El-Refaie, Thomas M. Jahns, Donald W. Novotny
Electrical and Computer Engineering Faculty Research and Publications
This paper presents a closed-form analytical technique for analyzing surface PM machines equipped with fractional-slot concentrated windings. Since this class of winding configuration deviates significantly from conventional sinusoidal distributions, classical steady-state phasor or analytical techniques cannot be used to provide accurate results. The presented analytical model provides a fast and reliable method to analyze and compare candidate machine designs. Stator slotting effects are taken into consideration and a wide range of concentrated winding configurations can be analyzed. This technique is capable of analyzing the machine both below (constant-torque) and above (flux-weakening) base speed. Average torque, cogging torque, and ripple torque …
On Innovative Methods Of Induction Motor Interturn And Broken-Bar Fault Diagnostics, Behrooz Mirafzal, Nabeel Demerdash
On Innovative Methods Of Induction Motor Interturn And Broken-Bar Fault Diagnostics, Behrooz Mirafzal, Nabeel Demerdash
Electrical and Computer Engineering Faculty Research and Publications
A fault indicator, the so-called swing angle, for broken-bar and interturn faults is investigated in this paper. This fault indicator is based on the rotating magnetic-field pendulous-oscillation concept in faulty squirrel-cage induction motors. Using the "swing-angle indicator," it will be demonstrated here that an interturn fault can be detected even in the presence of machine manufacturing imperfections. Meanwhile, a broken-bar fault can be detected under both direct-line and PWM excitations, even under the more difficult condition of partial-load levels. These two conditions of partial load and motor manufacturing imperfections, which are considered as difficult situations for fault detection, are investigated …
Statistical Correlation Of Gain And Buildup Time In Apds And Its Effects On Receiver Performance, Peng Sun, Majeed M. Hayat, Bahaa E.A. Saleh, Malvin Carl Teich
Statistical Correlation Of Gain And Buildup Time In Apds And Its Effects On Receiver Performance, Peng Sun, Majeed M. Hayat, Bahaa E.A. Saleh, Malvin Carl Teich
Electrical and Computer Engineering Faculty Research and Publications
This paper reports a novel recurrence theory that enables us to calculate the exact joint probability density function (pdf) of the random gain and the random avalanche buildup time in avalanche photodiodes (APDs) including the effect of dead space. Such calculations reveal a strong statistical correlation between the gain and the buildup time for all widths of the multiplication region. To facilitate the calculation of the photocurrent statistics in the presence of this correlation, the impulse-response function of the APD is approximately modeled by a function of time whose prespecified shape is appropriately parameterized by two random variables: the gain …
Characterization Of Metal And Metal Alloy Films As Contact Materials In Mems Switches, Hyukjae Lee, Ronald A. Coutu Jr., Shankar Mall, Kevin D. Leedy
Characterization Of Metal And Metal Alloy Films As Contact Materials In Mems Switches, Hyukjae Lee, Ronald A. Coutu Jr., Shankar Mall, Kevin D. Leedy
Electrical and Computer Engineering Faculty Research and Publications
This study presents a basic step toward the selection methodology of electric contact materials for microelectromechanical systems (MEMS) metal contact switches. This involves the interrelationship between two important parameters, resistivity and hardness, since they provide the guidelines and assessment of contact resistance, wear, deformation and adhesion characteristics of MEMS switches. For this purpose, thin film alloys of three noble metals, platinum (Pt), rhodium (Rh) and ruthenium (Ru) with gold (Au), were investigated. The interrelationship between resistivity and hardness was established for three levels of alloying of these metals with gold. Thin films of gold (Au), platinum (Pt), ruthenium (Rh) and …
Detection Efficiencies And Generalized Breakdown Probabilities For Nanosecond-Gated Near Infrared Single-Photon Avalanche Photodiodes, David A. Ramirez, Majeed M. Hayat, Gauri Karve, Joe C. Campbell, Sergio N. Torres, Bahaa E.A. Saleh, Malvin Carl Teich
Detection Efficiencies And Generalized Breakdown Probabilities For Nanosecond-Gated Near Infrared Single-Photon Avalanche Photodiodes, David A. Ramirez, Majeed M. Hayat, Gauri Karve, Joe C. Campbell, Sergio N. Torres, Bahaa E.A. Saleh, Malvin Carl Teich
Electrical and Computer Engineering Faculty Research and Publications
A rigorous model is developed for determining single-photon quantum efficiency (SPQE) of single-photon avalanche photodiodes (SPADs) with simple or heterojunction multiplication regions. The analysis assumes nanosecond gated-mode operation of the SPADs and that band-to-band tunneling of carriers is the dominant source of dark current in the multiplication region. The model is then utilized to optimize the SPQE as a function of the applied voltage, for a given operating temperature and multiplication-region structure and material. The model can be applied to SPADs with In/sub 0.52/Al/sub 0.48/As or InP multiplication regions as well as In/sub 0.52/Al/sub 0.48/As--InP heterojunction multiplication regions for wavelengths …
Expanding Extracurricular Learning Opportunities Through International Engineering Student And Faculty Exchange, Mark Polczynski
Expanding Extracurricular Learning Opportunities Through International Engineering Student And Faculty Exchange, Mark Polczynski
Electrical and Computer Engineering Faculty Research and Publications
No abstract provided.
Statistical Adaptive Sensing By Detectors With Spectrally Overlapping Bands, Ünal Sakog ̆ Lu, Majeed M. Hayat, J. Scott Tyo, Philip Dowd, Senthil Annamalai, Kalyan T. Posani, Sanjay Krishna
Statistical Adaptive Sensing By Detectors With Spectrally Overlapping Bands, Ünal Sakog ̆ Lu, Majeed M. Hayat, J. Scott Tyo, Philip Dowd, Senthil Annamalai, Kalyan T. Posani, Sanjay Krishna
Electrical and Computer Engineering Faculty Research and Publications
It has recently been reported that by using a spectral-tuning algorithm, the photocurrents of multiple detectors with spectrally overlapping responsivities can be optimally combined to synthesize, within certain limits, the response of a detector with an arbitrary responsivity. However, it is known that the presence of noise in the photocurrent can degrade the performance of this algorithm significantly, depending on the choice of the responsivity spectrum to be synthesized. We generalize this algorithm to accommodate noise. The results are applied to quantum-dot mid-infrared detectors with bias-dependent spectral responses. Simulation and experiment are used to show the ability of the algorithm …
Computation Of Bit-Error Probabilities For Optical Receivers Using Thin Avalanche Photodiodes, Byonghyok Choi, Majeed M. Hayat
Computation Of Bit-Error Probabilities For Optical Receivers Using Thin Avalanche Photodiodes, Byonghyok Choi, Majeed M. Hayat
Electrical and Computer Engineering Faculty Research and Publications
The large-deviation-based asymptotic-analysis and importance-sampling methods for computing bit-error probabilities for avalanche-photodiode (APD) based optical receivers, developed by Letaief and Sadowsky [IEEE Trans. Inform. Theory, vol. 38, pp. 1162-1169, 1992], are extended to include the effect of dead space, which is significant in high-speed APDs with thin multiplication regions. It is shown that the receiver's bit-error probability is reduced as the magnitude of dead space increases relative to the APD's multiplication-region width. The calculated error probabilities and receiver sensitivities are also compared with those obtained from the Chernoff bound.
Multi-Model Kalman Filtering For Adaptive Nonuniformity: Correction In Infrared Sensors, Jorge E. Pezoa, Majeed M. Hayat, Sergio N. Torres, Md. Saifur Rahman
Multi-Model Kalman Filtering For Adaptive Nonuniformity: Correction In Infrared Sensors, Jorge E. Pezoa, Majeed M. Hayat, Sergio N. Torres, Md. Saifur Rahman
Electrical and Computer Engineering Faculty Research and Publications
This paper presents an adaptive technique for the estimation of nonuniformity parameters of infrared focal-plane arrays that is robust with respect to changes and uncertainties in scene and sensor characteristics. The proposed algorithm is based on using a bank of Kalman filters in parallel. Each filter independently estimates state variables comprising the gain and the bias matrices of the sensor, according to its own dynamical-model parameters, which underly the statistics of the scene and the nonuniformity as well as the temporal drift in the nonuniformity. The supervising component of the algorithm then generates the final estimates of the state variables …