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Electrical and Computer Engineering Faculty Research & Creative Works

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A Fuzzy Based Load Model For Power System Direct Load Control, K. Bhattacharyya, Mariesa Crow Sep 1995

A Fuzzy Based Load Model For Power System Direct Load Control, K. Bhattacharyya, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Demand side management programs are strategies designed to alter the shape of the load curve. In order to successfully implement such a strategy, customer acceptance of the program is vital. It is thus desirable to design a model for direct load control which may accommodate customer preferences. This paper presents a methodology for optimizing both customer satisfaction and utility unit commitment savings, based on a fuzzy load model for the direct load control of appliances.

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A Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, James L. Drewniak Aug 1995

A Comparison Of Fdtd Algorithms For Subcellular Modeling Of Slots In Shielding Enclosures, Kuang-Ping Ma, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Thin slot modeling for the finite-difference time-domain (PDTD) method is investigated. Two subcellular algorithms for modeling thin slots with the FDTD method are compared for application to shielding enclosures in EMC. The stability of the algorithms is investigated, and comparisons between the two methods for slots in planes, and slots in loaded cavities are also made.

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Fdtd Modeling Of Thin Wires For Simulating Common-Mode Radiation From Structures With Attached Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren Aug 1995

Fdtd Modeling Of Thin Wires For Simulating Common-Mode Radiation From Structures With Attached Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

The analysis of shielding enclosures is complicated by the existence of apertures and cables. The finite-difference time-domain (FDTD) method can model shielding enclosures with complex geometries, but has difficulty modeling wires and cables of arbitrary radii. Modeling the wire by setting the axial component of the electric field to zero in the FDTD results in a wire with a radius determined by the mesh discretisation. Neglecting wire radius in applications such as electromagnetic interference (EMI) or printed circuit board modeling may result in gross errors because near field quantities are typically sensitive to wire thickness. Taflove (1990) developed a wire …

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Study Of Interconnect Vias By The Discrete Surface Integral Method, Hao Shi, James L. Drewniak Aug 1995

Study Of Interconnect Vias By The Discrete Surface Integral Method, Hao Shi, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A non-orthogonal time-domain full-wave solver, is developed based on the Discrete Surface Integral (DSI) technique. Closed form expressions are derived for the coefficients used in the leap-frog computation scheme so that the DSI technique can be implemented as a generalized finite-difference procedure. This procedure is employed to investigate the propagation characteristics of a typical interconnect via in printed circuits. The numerically calculated scattering parameters show consistent behavior with measured results. A square via with equal area is also evaluated.

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An Experimental Investigation Of 4-Layer Printed Circuit Board Decoupling, Todd H. Hubing, Thomas Van Doren, Fei Sha, James L. Drewniak, Michael J. Wilhelm Aug 1995

An Experimental Investigation Of 4-Layer Printed Circuit Board Decoupling, Todd H. Hubing, Thomas Van Doren, Fei Sha, James L. Drewniak, Michael J. Wilhelm

Electrical and Computer Engineering Faculty Research & Creative Works

This paper examines the measured power bus impedance of fully populated 4-layer printed circuit boards with internal power and ground planes. Three boards provided by two leading computer companies were evaluated. Each of the state-of-the-art high-speed boards used in this study employed surface-mount decoupling capacitors to reduce noise on the power bus. The boards were measured with and without some or all of their decoupling capacitance. The effectiveness of the decoupling capacitors as a function of location and frequency and the relationship between board impedance and power bus noise was explored. The behavior of 4-layer boards is shown to be …

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Integrating Electromagnetic Compatibility Laboratory Exercises Into Undergraduate Electromagnetics, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha Aug 1995

Integrating Electromagnetic Compatibility Laboratory Exercises Into Undergraduate Electromagnetics, James L. Drewniak, Todd H. Hubing, Thomas Van Doren, Fei Sha

Electrical and Computer Engineering Faculty Research & Creative Works

A state-of-the art high-frequency laboratory is being developed for pursuing laboratory exercises in EMC. These exercises are being integrated into three undergraduate electromagnetics courses. Two of the courses are a required introductory sequence. The laboratory exercises are designed to stimulate students interest, motivate them to learn concepts, and provide them with exposure to practical EMC applications. Laboratory exercises are also an integral part of an EMC elective course. This paper describes the laboratory development and discusses experiments that can be integrated into these three courses for teaching fundamental electromagnetics as well as EMC.

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Diagnosing And Modeling Common-Mode Radiation From Printed Circuit Boards With Attached Cables, James L. Drewniak, Fei Sha, Todd H. Hubing, Thomas Van Doren, J. Shaw Aug 1995

Diagnosing And Modeling Common-Mode Radiation From Printed Circuit Boards With Attached Cables, James L. Drewniak, Fei Sha, Todd H. Hubing, Thomas Van Doren, J. Shaw

Electrical and Computer Engineering Faculty Research & Creative Works

A procedure for diagnosing and modeling radiation from printed circuit boards with attached cables is presented through a case study of a production model electronic control unit. Procedures for determining EMI antennas, IC sources, and mechanisms by which noise is coupled from the IC source to the antenna are suggested.

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Power Bus Decoupling On Multilayer Printed Circuit Boards, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, David M. Hockanson May 1995

Power Bus Decoupling On Multilayer Printed Circuit Boards, Todd H. Hubing, James L. Drewniak, Thomas Van Doren, David M. Hockanson

Electrical and Computer Engineering Faculty Research & Creative Works

Guidelines for the selection and placement of decoupling capacitors that work well for one-sided or two-sided printed circuit boards are not appropriate for multilayer boards with power and ground planes. Boards without internal planes take advantage of the power bus inductance to help decouple components at the higher frequencies. An effective decoupling strategy for multilayer boards must account for the low inductance and relatively high capacitance of the power bus.

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Microwave Detection Optimization Of Disbond In Layered Dielectrics With Varying Thickness, Stoyan I. Ganchev, Nasser N. Qaddoumi, Emarit Ranu, R. Zoughi Apr 1995

Microwave Detection Optimization Of Disbond In Layered Dielectrics With Varying Thickness, Stoyan I. Ganchev, Nasser N. Qaddoumi, Emarit Ranu, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

The detection sensitivity optimization of air disbond in layered dielectric composites, using an open-ended rectangular waveguide, is studied both theoretically and experimentally. The sensitivity of the disbond detection is strongly influenced by the proper choice of parameters such as the operating frequency and the layered composite geometry (conductor backed or terminated by an infinite half-space of air). The capability of optimizing the measurement system parameters to detect and estimate the thickness of a disbonded layer independent of some changes in the thickness of the dielectric coating is also demonstrated. The impact of the parameters influencing detection optimization is theoretically investigated …

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On-Line Cursive Korean Character Recognition By Using Curvature Models, Chang-Soo Kim, Byung Hwan Jun, Moo Young Kim, Woo Seong Kim, Jaihie Kim Jan 1995

On-Line Cursive Korean Character Recognition By Using Curvature Models, Chang-Soo Kim, Byung Hwan Jun, Moo Young Kim, Woo Seong Kim, Jaihie Kim

Electrical and Computer Engineering Faculty Research & Creative Works

A cursive Korean character consists of several Korean alphabets where connection is present within and among the alphabets. Recognition of Korean characters can be carried out by splitting each character into smaller primitives. Small line segments can be used as the primitives. But this approach requires too much processing time, for there can be many candidate references to be matched to one input character and each reference usually consists of too many primitives. In this paper, we propose an approach using structural curvature models to overcome the difficulties of using small line segments. These models are obtained by segmenting the …

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Maximum-Likelihood Time Delay Estimation: A New Perspective, John A. Stuller, Nancy Hubing Jan 1995

Maximum-Likelihood Time Delay Estimation: A New Perspective, John A. Stuller, Nancy Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Introduces a New Realization for Maximum Likelihood Time-Delay Estimation. the New Realization Illuminatesthe Relationships between Maximum Likelihood Time Delay Estimation and Other Methods. We Obtain the Result by Deriving the Likelihood Function using a Fundamental Method that, Surprisingly, Appears to Be New to The field of Array Processing. This Method is a Natural Complement to the Karhunen-Loeve Transform Having Vector Eigenfunctions and Scalar Eigenvalues, and It Generalizes to M Measurements, M 2 2. Moreover, It Can Be Applied to Other Multichannel estimation problems.

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A Two-Dimensional Image Model Based On Occlusion And Maximum Entropy, John A. Stuller Jan 1995

A Two-Dimensional Image Model Based On Occlusion And Maximum Entropy, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

This Paper Provides New Insights into the Formation of Two-Dimensional Image Autocorrelation Functions. We Model an Image as a Maximum-Entropy Composition of Individual Occluding Object Images that Have Random Positions, Shapes and Intensities. We Derive the Autocorrelation Function of This Image Model, Give an Example, and Comment on the Reasonableness of the Frequently-Made Assumptions of Autocovariance Separability and Isotropy.

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Least Squares Order-Recursive Lattice Smoothers, Jenq Tay Yuan, John A. Stuller Jan 1995

Least Squares Order-Recursive Lattice Smoothers, Jenq Tay Yuan, John A. Stuller

Electrical and Computer Engineering Faculty Research & Creative Works

Conventional Least Squares Order-Recursive Lattice (LSORL) Filters Use Present and Past Data Values to Estimate the Present Value of a Signal. This Paper Introduces LSORL Smoothers Which Use Past, Present and Future Data for that Purpose. Except for an overall Delay Needed for Physical Realization, LSORL Smoothers Can Substantially Outperform LSORL Filters While Retaining All the Advantages of an Order-Recursive Structure. © 1995 IEEE

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A Universal Power Converter For Emergency Charging Of Electric Vehicle Batteries, Norman R. Cox Jan 1995

A Universal Power Converter For Emergency Charging Of Electric Vehicle Batteries, Norman R. Cox

Electrical and Computer Engineering Faculty Research & Creative Works

An on-board electric vehicle battery charger capable of accepting AC or DC inputs in the range of 12 to 260 volts is described. The charger provides near-unity power factor and high efficiency for routine charging from AC sources, but can also be used to tap other sources of power in the event of an emergency.

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The Fast Affine Projection Algorithm, Steven L. Grant, S. Tavathia Jan 1995

The Fast Affine Projection Algorithm, Steven L. Grant, S. Tavathia

Electrical and Computer Engineering Faculty Research & Creative Works

This paper discusses a new adaptive filtering algorithm called fast affine projections (FAP). FAP''s key features include LMS like complexity and memory requirements (low), and RLS like convergence (fast) for the important case where the excitation signal is speech. Another of FAP''s important features is that it causes no delay in the input or output signals. In addition, the algorithm is easily regularized resulting in robust performance even for highly colored excitation signals. The combination of these features make FAP an excellent candidate for the adaptive filter in the acoustic echo cancellation problem. A simple, low complexity numerical stabilization method …

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Conservative Thirty Calendar Day Stock Prediction Using A Probabilistic Neural Network, H. Tan, Donald C. Wunsch, Danil V. Prokhorov Jan 1995

Conservative Thirty Calendar Day Stock Prediction Using A Probabilistic Neural Network, H. Tan, Donald C. Wunsch, Danil V. Prokhorov

Electrical and Computer Engineering Faculty Research & Creative Works

We describe a system that predicts significant short-term price movement in a single stock utilizing conservative strategies. We use preprocessing techniques, then train a probabilistic neural network to predict only price gains large enough to create a significant profit opportunity. Our primary objective is to limit false predictions (known in the pattern recognition literature as false alarms). False alarms are more significant than missed opportunities, because false alarms acted upon lead to losses. We can achieve false alarm rates as low as 5.7% with the correct system design and parameterization.

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The Influence Of Pcl 3 On Planarisation And Selectivity Of Inp Regrowth By Atmospheric Pressure Movpe, M. J. Harlow, P. C. Spurdens, Randy Hays Moss Jan 1995

The Influence Of Pcl 3 On Planarisation And Selectivity Of Inp Regrowth By Atmospheric Pressure Movpe, M. J. Harlow, P. C. Spurdens, Randy Hays Moss

Electrical and Computer Engineering Faculty Research & Creative Works

The introduction of phosphorus trichloride into the AP-MOVPE growth of InP has been found to dramatically improve the regrowth adjacent to mesa structures. By suppressing growth in the [100] direction and enhancing growth in the [311] directions planar regrowth is achieved. Polycrystalline deposits on dielectric masks can also be completely suppressed

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Performance Of Ai Methods In Detecting Melanoma, Arve Kjoelen, M. J. Thompson, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker Jan 1995

Performance Of Ai Methods In Detecting Melanoma, Arve Kjoelen, M. J. Thompson, Scott E. Umbaugh, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

This research has shown that features extracted from color skin tumor images by computer vision methods can be reliable discriminators of malignant tumors from benign ones. Reliability was demonstrated by the monotonically increasing success ratios with increasing training set size and by the small standard deviations from the mean success rates. An average success rate of 70 percent in diagnosing melanoma was attained for a training set size of 60 percent. The presence or absence of atypical moles in the training and test sets was shown to have a dramatic impact on the effectiveness of the generated classification rules. This …

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Remote Detection Of Acoustic Boundaries Using Radiation Imaging Operators, Richard E. Dubroff, Md. Ishfaqur Raza, Thomas J. Herrick Jan 1995

Remote Detection Of Acoustic Boundaries Using Radiation Imaging Operators, Richard E. Dubroff, Md. Ishfaqur Raza, Thomas J. Herrick

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we present an acoustic imaging operator. This operator is based upon combining the material boundary conditions at an acoustic boundary and the radiation boundary conditions associated with one way wave propagation. Numerical examples, using the second-order imaging operator, are presented in order to demonstrate the applicability of this method to the detection of two-dimensional boundaries.

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The Performance Of Reed-Solomon Codes On A Bursty-Noise Channel, William J. Ebel, William H. Tranter Jan 1995

The Performance Of Reed-Solomon Codes On A Bursty-Noise Channel, William J. Ebel, William H. Tranter

Electrical and Computer Engineering Faculty Research & Creative Works

The performance of a Reed-Solomon coded binary communication system on a bursty-noise channel is considered. Bursty noise is defined to be background Gaussian noise plus burst noise, where burst noise is defined to be a series of finite-duration Gaussian-noise pulses with fixed duration and Poisson occurrence times. Using the noise model, along with ideal symbol interleaving, decoded bit-error probability bounds are derived for the case where the noise bursts are long with respect to the channel symbol rate. Specific performance results are presented for the (31,15,8) Reed-Solomon Joint Tactical Distribution System (JTIDS) code with a Binary Phase Shift Keyed (BPSK) …

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Hardware Assists For High Performance Computing Using A Mathematics Of Arrays, Hardy J. Pottinger, W. Eatherton, J. Kelly, T. Schiefelbein, Lenore Mullin, R. Ziegler Jan 1995

Hardware Assists For High Performance Computing Using A Mathematics Of Arrays, Hardy J. Pottinger, W. Eatherton, J. Kelly, T. Schiefelbein, Lenore Mullin, R. Ziegler

Electrical and Computer Engineering Faculty Research & Creative Works

Work in progress at the University of Missouri-Rolla on hardware assists for high performance computing is presented. This research consists of a novel field programmable gate array (FPGA) based reconfigurable coprocessor board (the Chameleon Coprocessor) being used to evaluate hardware architectures for speedup of array computation algorithms. These algorithms are developed using a Mathematics of Arrays (MOA). They provide a means to generate addresses for data transfers that require less data movement than more traditional algorithms. In this manner, the address generation algorithms are acting as an intelligent data prefetching mechanism or special purpose cache controller. Software implementations have been …

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The Structure And Phase Equilibria Of Salt-Water Solution At Supercritical Conditions, S. T. Cui, J. G. Harris Jan 1995

The Structure And Phase Equilibria Of Salt-Water Solution At Supercritical Conditions, S. T. Cui, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

We study the thermodynamic properties of the supercritical water and dilute aqueous salt solutions using molecular dynamics simulation, The sodium and chloride ions are found to show strong pairing at conditions corresponding to those of supercritical water oxidation, we also present the first prediction of the solubility of sodium chloride in supercritical water obtained directly from intermolecular interactions using molecular simulations. © 1995 Plenum Publishing Corporation.

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Solubility Of Sodium Chloride In Supercritical Water: A Molecular Dynamics Study, S. T. Cui, J. G. Harris Jan 1995

Solubility Of Sodium Chloride In Supercritical Water: A Molecular Dynamics Study, S. T. Cui, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

We study the solubility of sodium chloride in steam and supercritical water at temperatures from 450 to 550 °C and pressures from 100 to 300 bar as predicted by the simple point charge water model and a simple model of the ions. We calculated the chemical potential of the sodium chloride dimer in supercritical water using a Kirkwood coupling parameter integration in which we computed via molecular simulation the reversable work required to increase the NaCl-water interactions from some reduced value to their full strength. The contribution to the chemical potential of the NaCl particle with reduced interactions we computed …

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Learning To Ignore: Psychophysics And Computational Modeling Of Fast Learning Of Direction In Noisy Motion Stimuli, Lucia M. Vaina, V. Sundareswaran, John G. Harris Jan 1995

Learning To Ignore: Psychophysics And Computational Modeling Of Fast Learning Of Direction In Noisy Motion Stimuli, Lucia M. Vaina, V. Sundareswaran, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

The effects of practice on the discrimination of direction of motion in briefly presented noisy dynamic random dot patterns are investigated in several forced-choice psychophysical tasks. We found that the percentage of correct responses on any specific task increases linearly with repetition of trials within roughly 200 trials from about chance to a performance of 90% or better. The level of performance remained constant or improved over several days, and in most instances, it did not transfer when stimulus parameters changed. We used a modified Radial Basis Function (RBF) representation to model the psychophysical tasks. The performance of the model …

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A Bipartite, Differential I Ddq Testable Static Ram Design, Waleed K. Al-Assadi, A. P. Jayasumana, Y. K. Malaiya Jan 1995

A Bipartite, Differential I Ddq Testable Static Ram Design, Waleed K. Al-Assadi, A. P. Jayasumana, Y. K. Malaiya

Electrical and Computer Engineering Faculty Research & Creative Works

I DDQ (Defect Detection by Quiescent power supply current measurement), or current testing, has emerged in the last few years as an effective technique for detecting certain classes of faults in high-density ICs. In this paper, a testable design that enhances the I DDQ testability of static random access memories (SRAMs) for off-line testing as proposed. To achieve high accuracy and a test speed approaching the system operational speed, the memory is partitioned for comparison of I DDQ values. Parallel write/read operations are used to activate possible faults, while quiescent power supply currents from two blocks are compared

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A New Approch To Low Drift Ta₂O₅ By Ph Reactive Sputtering And Sol-Gel Method, Chang-Soo Kim, Dae-Hyuk Kwon, Byung-Woog Cho, Byung-Ki Sohn Jan 1995

A New Approch To Low Drift Ta₂O₅ By Ph Reactive Sputtering And Sol-Gel Method, Chang-Soo Kim, Dae-Hyuk Kwon, Byung-Woog Cho, Byung-Ki Sohn

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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A New Ph-Isfet Based Dissolved Oxygen Sensor, Chang-Soo Kim, Dae-Hyuk Kwon, Byung-Ki Sohn Jan 1995

A New Ph-Isfet Based Dissolved Oxygen Sensor, Chang-Soo Kim, Dae-Hyuk Kwon, Byung-Ki Sohn

Electrical and Computer Engineering Faculty Research & Creative Works

"A new dissolved oxygen sensor based on pH-ISFET has been discussed. A platinum working electrode surrounding a pH-sensing gate of the pH-ISFET electrolyzes dissolved oxygen, resulting in a corresponding pH change. The pH-ISFET can determine dissolved oxygen concentration through detecting this pH change."--Summary

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A Flux-Weakening Strategy For Current-Regulated Surface-Mounted Permanent-Magnet Machine Drives, Keith Corzine, S. D. Sudhoff, H. J. Hegner Jan 1995

A Flux-Weakening Strategy For Current-Regulated Surface-Mounted Permanent-Magnet Machine Drives, Keith Corzine, S. D. Sudhoff, H. J. Hegner

Electrical and Computer Engineering Faculty Research & Creative Works

Permanent-magnet synchronous machines fed from current-regulated converters feature nearly ideal performance at low-to-moderate speeds. However, as rotor speed increases the back emf rises which results in loss of current regulation and decreased torque. In buried-magnet machine drives, flux weakening is often used to extend the speed range. This paper sets forth a flux-weakening control specifically designed for surface-mounted permanent-magnet machines which is simple and does not require knowledge of the machine or system parameters. The proposed method is demonstrated both experimentally and through the use of computer simulation

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Analysis Of A Current-Regulated Brushless Dc Drive, Keith Corzine, S. D. Sudhoff, H. J. Hegner Jan 1995

Analysis Of A Current-Regulated Brushless Dc Drive, Keith Corzine, S. D. Sudhoff, H. J. Hegner

Electrical and Computer Engineering Faculty Research & Creative Works

Current-regulated brushless DC machines are used in a wide variety of applications including robotics, actuators, electric vehicles, and ship propulsion systems. When conducting system analysis of this or any other type of drive, average-value reduced-order models are invaluable since they provide a means of rapidly predicting the electromechanical dynamics and are readily linearized for control system synthesis. In this paper, a highly accurate average-value reduced-order model of a hysteresis current-regulated brushless DC drive is set forth. In so doing it is demonstrated that the drive exhibits five distinct operating modes. The physical cause of each of these modes is explained …

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The Multirate Simulation Of Facts Devices In Power System Dynamics, J. G. Chen, Mariesa Crow Jan 1995

The Multirate Simulation Of Facts Devices In Power System Dynamics, J. G. Chen, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the multirate method is applied to the problem of simulating the dynamics of a power system which contains fast components such as induction machine loads and FACTS devices. Results concerning the numerical stability and accuracy of the multirate method are presented. Implementation concerns are also addressed by studying an example power system which contains a wide range of time response behavior

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