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Electrical and Computer Engineering Faculty Research & Creative Works

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Full-Text Articles in Engineering

Modeling Emi Resulting From A Signal Via Transition Through Power/Ground Layers, Wei Cui, Xiaoning Ye, Bruce Archambeault, Doug White, Min Li, James L. Drewniak Mar 2000

Modeling Emi Resulting From A Signal Via Transition Through Power/Ground Layers, Wei Cui, Xiaoning Ye, Bruce Archambeault, Doug White, Min Li, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Signal transitioning through layers on vias are very common in multi-layer printed circuit board (PCB) design. For a signal via transitioning through the internal power and ground planes, the return current must switch from one reference plane to another reference plane. The discontinuity of the return current at the via excites the power and ground planes, and results in noise on the power bus that can lead to signal integrity, as well as EMI problems. Numerical methods, such as the finite-difference time-domain (FDTD), Moment of Methods (MoM), and partial element equivalent circuit (PEEC) method, were employed herein to study this …

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Emi Model Validation And Standard Challenge Problems, Bruce Archambeault, James L. Drewniak Mar 2000

Emi Model Validation And Standard Challenge Problems, Bruce Archambeault, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

A joint effort of the IEEE/EMC Society TC-9 Committee and the Applied Computational Electromagnetic Society (ACES) resulted in a central web location for contributors who will provide model and measurement data to share and compare with others. In addition to the data repository, a set of standard challenge problems have been proposed over the past few years, and are located at the web site. The site will be carefully monitored by a review committee to insure only high-quality information is posted on the site.

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Microwave Near-Field Reflection Property Analysis Of Concrete For Material Content Determination, Karl Joseph Bois, Aaron D. Benally, R. Zoughi Feb 2000

Microwave Near-Field Reflection Property Analysis Of Concrete For Material Content Determination, Karl Joseph Bois, Aaron D. Benally, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

One of the most important parameters associated with concrete is its compressive strength. Currently, there is no reliable nondestructive testing technique that is capable of robust determination of this parameter. Concrete is a heterogeneous mixture composed of water, cement powder, sand (fine aggregate), rocks of various size or grade (coarse aggregate), and air (porosity). Water and cement powder chemically combine into a cement paste binder which, in due curing time (28 days), produces concrete with its specified compressive strength. Compressive strength of concrete is strongly influenced by its water-to-cement (w/c) ratio as well as its coarse aggregate-to-cement (ca/c) ratio. Therefore, …

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Collaborative Distance Education In Power Engineering, Anil Pahwa, Shelli K. Starrett, Kraig J. Olejniczak, S. D. Sudhoff, Mariesa Crow Feb 2000

Collaborative Distance Education In Power Engineering, Anil Pahwa, Shelli K. Starrett, Kraig J. Olejniczak, S. D. Sudhoff, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a perspective on offering "shared-courses," or courses simultaneously offered at two or more universities via various distance educational frameworks. Over a three year duration, two senior/graduate level courses were jointly developed and offered to the students at the University of Missouri--Rolla, the University of Arkansas, Kansas State University, and Purdue University. This paper discusses the various distance educational technologies including two-way audio/visual via ISDN line, video-tapes, and web-based conferencing. Both instructor and student reactions to these mediums are included. Pedagogical methods appropriate for these mediums are outlined. The paper concludes with recommendations and strategies for engineering institutions …

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Emi From Cavity Modes Of Shielding Enclosures-Fdtd Modeling And Measurements, Min Li, Joe Nuebel, James L. Drewniak, Richard E. Dubroff, Todd H. Hubing, Thomas Van Doren Feb 2000

Emi From Cavity Modes Of Shielding Enclosures-Fdtd Modeling And Measurements, Min Li, Joe Nuebel, James L. Drewniak, Richard E. Dubroff, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) from slots and apertures resulting from coupling of interior sources through enclosure cavity modes in a rectangular test enclosure is reported herein. EMI from a specially designed test enclosure with slots or apertures excited by interior sources was studied experimentally and with finite-difference time-domain (FDTD) modeling. The measurements and FDTD modeling agree well. The results indicate that radiation at cavity mode resonances through slots and apertures of nonresonant dimensions can be as significant as the radiation at aperture or slot resonances. The agreement between the FDTD modeling and measurements demonstrates the usefulness of FDTD for investigating aspects …

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Control Of Statcom With Energy Storage Device, Chen Shen, Zhiping Yang, Stan Atcitty, Mariesa Crow Jan 2000

Control Of Statcom With Energy Storage Device, Chen Shen, Zhiping Yang, Stan Atcitty, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, the control method of a STATCOM with an energy storage device is discussed. To determine the switching level control, UPWM (unique pulse width modulation) and SPWM (sinusoidal pulse width modulation) methods are compared. A linearized model of a STATCOM with a battery is set up to derive monitoring level control strategies. All the control methods are verified by the PSCAD/EMTDC software package.

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A Schooling On Their Implications For Software Engineering [Trends], Ann K. Miller Jan 2000

A Schooling On Their Implications For Software Engineering [Trends], Ann K. Miller

Electrical and Computer Engineering Faculty Research & Creative Works

A discussion is presented on trends in software engineering. This can be done by simply extrapolating some of the popular, current trends. And, in fact, we examine a few of these obvious indicators. However, software engineering has had new approaches that are more revolutionary than evolutionary. In particular, we try to discern trends in software engineering based on trends in delivered software systems.

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Monaural Cue Sound Localizer, John G. Harris, Chiang Jung Pu, Jose C. Principe Jan 2000

Monaural Cue Sound Localizer, John G. Harris, Chiang Jung Pu, Jose C. Principe

Electrical and Computer Engineering Faculty Research & Creative Works

We describe the first single microphone sound localization system and its inspiration from theories of human monaural sound localization. Reflections and diffractions caused by the external ear (pinna) allow humans to estimate sound source elevations using only one ear. Our single microphone localization model relies on a specially shaped reflecting structure that serves the role of the pinna. Specially designed analog VLSI circuitry uses echo-time processing to localize the sound. A CMOS integrated circuit has been designed, fabricated, and successfully demonstrated on actual sounds.

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A Silicon Olfactory Bulb Oscillator, Vitor M.Grade Tavares, Jose C. Principe, John G. Harris Jan 2000

A Silicon Olfactory Bulb Oscillator, Vitor M.Grade Tavares, Jose C. Principe, John G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a low power MOS-VLSI implementation of an oscillator proposed by Freeman to model a very important component of the olfactory cortex. The model dynamics has time constants in the order of 1/220 (s). To accomplish the long-time constants a new filtering technique recently proposed was utilized. All the blocks involving information processing were designed to operate below threshold (weak inversion).

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Automated Identification Of The Operational Modes Of Switched Electric Circuits, J. Jatskevich, O. Wasynczuk, E. A. Walters, C. E. Lucas, Steven Pekarek, P. T. Lamm Jan 2000

Automated Identification Of The Operational Modes Of Switched Electric Circuits, J. Jatskevich, O. Wasynczuk, E. A. Walters, C. E. Lucas, Steven Pekarek, P. T. Lamm

Electrical and Computer Engineering Faculty Research & Creative Works

In the analysis of power-electronic-based energy conversion systems, it is important to identify the operational modes of the associated converters and inverters. However, as the number of switching elements increases, it becomes more difficult to analytically establish all possible modes of operation. In this paper, a modelling technique is described wherein a state-space representation of the overall system is generated automatically and updated dynamically as each new topology is encountered. Utilizing this approach, it becomes possible to identify the operational modes of converters and inverters based upon the cyclically repeated sequences of topologies that can be observed during steady-state operation. …

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A Novel Fpga-Based Master/Slave Pci Interface Core, Chris Brueggen, Hardy J. Pottinger Jan 2000

A Novel Fpga-Based Master/Slave Pci Interface Core, Chris Brueggen, Hardy J. Pottinger

Electrical and Computer Engineering Faculty Research & Creative Works

Current high-density, high-speed devices such as Xilinx's Virtex FPGAs are more than capable of implementing a 64-bit, 66 MHz PCI bus interface and associated application specific logic. This paper presents a novel design for an FPGA-based PCI bus interface, which is being used in the development of a medical ultrasound instrument.

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An Analog Front-End Speech Processor Using The Ratio Spectrum, John G. Harris, Shao Jen Lim Jan 2000

An Analog Front-End Speech Processor Using The Ratio Spectrum, John G. Harris, Shao Jen Lim

Electrical and Computer Engineering Faculty Research & Creative Works

We have combined the standard front-end filter bank with a feature extraction process to produce a model that requires dramatically less hardware (or software). This new model, based on the frequency-sampled ratio spectrum, can be interpreted as a small set of constant-Q filters whose center frequencies adapt to locations of high signal energy. The resulting feature vectors are shown to outperform several competing techniques for phoneme recognition. Results from fabricated CMOS analog VLSI circuits illustrate a hardware efficient method to sample the ratio spectrum.

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A Probabilistic Analysis Of The Ratio Spectrum, M. D. Skowronski, J. G. Harris Jan 2000

A Probabilistic Analysis Of The Ratio Spectrum, M. D. Skowronski, J. G. Harris

Electrical and Computer Engineering Faculty Research & Creative Works

Recently, Lim and Harris (see IEEE International Symposium on Circuits and Systems, p.277-80, June 1998) developed a novel spectral representation called the ratio spectrum. The ratio spectrum is formed by taking the ratio of the power of a low pass filtered signal to the power of the original unfiltered signal for all filter cutoff frequencies. Features extracted from the ratio spectrum have proven to be promising for phoneme recognition and speech compression. In this work we have shown that the ratio spectrum feature sets are competitive with standard feature sets used for automatic speech recognition. To understand the underlying properties …

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Decentralized Online Neuro-Identification Of Turbogenerators In A Multi-Machine Power System, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2000

Decentralized Online Neuro-Identification Of Turbogenerators In A Multi-Machine Power System, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a new and a novel technique based on Artificial Neural Networks (ANNs) for nonlinear model of turbogenerators in a multi-machine power system. Only local measurements are required by each ANN in this new method, and hence it is called decentralized neuro-identificiation. Each turbogenerator in the power system is quipped with an ANN which is able to identify (or model) its particular turbogenerator from moment to moment This information can then be used by a second ANN at each generator to enable effective control of the nonlinear non-stationary process under all operating conditions. Simulation results are presented in …

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A Hysteresis Current-Regulated Control For Multi-Level Drives, Keith Corzine Jan 2000

A Hysteresis Current-Regulated Control For Multi-Level Drives, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

Most multi-level converters are controlled through the use of voltage-source based control techniques such as space-vector modulation or multi-level sine-triangle modulation. However, in many applications such as field oriented drives, a high bandwidth current-source inverter based control is more desirable. In this paper, the concept of a multi-level hysteresis current-source control is set forth. The new control is experimentally verified using a four-level converter/induction motor drive system and the results are compared to a space vector modulation controller. A dynamic study involving a step change in current command demonstrates the controls high bandwidth.

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Adaptive Critic Based Neurocontroller For Turbogenerators With Global Dual Heuristic Programming, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2000

Adaptive Critic Based Neurocontroller For Turbogenerators With Global Dual Heuristic Programming, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

Turbogenerators are nonlinear time varying systems. This paper presents the design of a neurocontroller for such a turbogenerator that augments/replaces the traditional automatic voltage regulator (AVR) and the turbine governor using a novel technique based on the adaptive critic designs (ACDs) with emphasis on global dual heuristic programming (GDHP). Simulation results are presented to show that the neurocontroller derived with the GDHP approach is robust and its performance is better when compared with that derived with other neural network technique, especially when system conditions and configuration changes.

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Analysis Of A Novel Four-Level Dc/Dc Boost Converter, Keith Corzine, Sonal K. Majeethia Jan 2000

Analysis Of A Novel Four-Level Dc/Dc Boost Converter, Keith Corzine, Sonal K. Majeethia

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, novel two-quadrant buck/boost and one-quadrant boost four-level DC/DC power converters are introduced. The primary application for these converters is that of interfacing a low-voltage DC source, such as a fuel cell or battery, to a high-voltage four-level inverter. One important feature of the four-level DC/DC power converters proposed is the ability to perform the power conversion and balance the inverter capacitor voltages simultaneously. With the capacitor voltage balancing, it is possible to obtain the full voltage from the inverter. For the boost converter, the steady-state and nonlinear average-value (NLAM) models are developed. The NLAM is verified against …

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Fourier Based Three Phase Power Metering System, Scott C. Smith, M. J. Devaney Jan 2000

Fourier Based Three Phase Power Metering System, Scott C. Smith, M. J. Devaney

Electrical and Computer Engineering Faculty Research & Creative Works

The increased application of higher frequency nonlinear loads, such as electronic fluorescent ballasts and higher speed adjustable drives, has resulted in the need to monitor the higher power system harmonics which were largely ignored in earlier power monitors. Addressing this need requires a meter with substantially higher sample rate and greater computational power. This paper describes a zero-blind, three-phase, three-element power meter that samples three voltages and four currents at 256 points per cycle. The instrument relies on the FFT to compute real and reactive power at each harmonic and reports total real, reactive, and distortion power on each phase. …

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Comparison Of A Heuristic Dynamic Programming And A Dual Heuristic Programming Based Adaptive Critics Neurocontroller For A Turbogenerator, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley Jan 2000

Comparison Of A Heuristic Dynamic Programming And A Dual Heuristic Programming Based Adaptive Critics Neurocontroller For A Turbogenerator, Ganesh K. Venayagamoorthy, Donald C. Wunsch, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of a neurocontroller for a turbogenerator that augments/replaces the conventional automatic voltage regulator and the turbine governor. The neurocontroller uses a novel technique based on the adaptive critic designs with emphasis on heuristic dynamic programming (HDP) and dual heuristic programming (DHP). Results are presented to show that the DHP based neurocontroller is robust and performs better than the HDP based neurocontroller, as well as the conventional controller, especially when the system conditions and configuration changes.

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Comparison Of Text-Dependent Speaker Identification Methods For Short Distance Telephone Lines Using Artificial Neural Networks, Ganesh K. Venayagamoorthy, N. Sundepersadh Jan 2000

Comparison Of Text-Dependent Speaker Identification Methods For Short Distance Telephone Lines Using Artificial Neural Networks, Ganesh K. Venayagamoorthy, N. Sundepersadh

Electrical and Computer Engineering Faculty Research & Creative Works

The transition to democracy in South Africa has brought with it certain challenges. The main challenge is to get rid of crime and corruption. The paper presents a technique to combat white-collar crime in telephone transactions by identifying and verifying speakers using artificial neural networks (ANNs). Results are presented to show that speaker identification is feasible and this is illustrated with two different types of ANN architectures and with two different types of characteristic features as inputs to ANNs.

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Neurocontroller Alternatives For "Fuzzy" Ball-And-Beam Systems With Nonuniform Nonlinear Friction, Danil V. Prokhorov, Donald C. Wunsch, Paul H. Eaton Jan 2000

Neurocontroller Alternatives For "Fuzzy" Ball-And-Beam Systems With Nonuniform Nonlinear Friction, Danil V. Prokhorov, Donald C. Wunsch, Paul H. Eaton

Electrical and Computer Engineering Faculty Research & Creative Works

The ball-and-beam problem is a benchmark for testing control algorithms. Zadeh proposed (1994) a twist to the problem, which, he suggested, would require a fuzzy logic controller. This experiment uses a beam, partially covered with a sticky substance, increasing the difficulty of predicting the ball's motion. We complicated this problem even more by not using any information concerning the ball's velocity. Although it is common to use the first differences of the ball's consecutive positions as a measure of velocity and explicit input to the controller, we preferred to exploit recurrent neural networks, inputting only consecutive positions instead. We have …

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Power Education At The Crossroads, Badrul H. Chowdhury Jan 2000

Power Education At The Crossroads, Badrul H. Chowdhury

Electrical and Computer Engineering Faculty Research & Creative Works

To meet the demands of designing and running far more complex and highly integrated electricity systems, a new kind of power engineer is needed. In this paper, the author describes how, though students tend to favor higher-tech and more lucrative fields than power Engineering; reports of the discipline''s demise are exaggerated

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Successful Proposal Preparation, Mariesa Crow Jan 2000

Successful Proposal Preparation, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

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Two Separate Continually Online Trained Neurocontrollers For Excitation And Turbine Control Of A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley Jan 2000

Two Separate Continually Online Trained Neurocontrollers For Excitation And Turbine Control Of A Turbogenerator, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents the design of two separate continually online trained (GOT) artificial neural network (ANN) controllers for excitation and turbine control of a turbogenerator connected to the infinite bus through a transmission line. These neurocontrollers augment/replace the conventional automatic voltage regulator and the turbine governor of a generator. A third COT ANN is used to identify the complex nonlinear dynamics of the power system. Results are presented to show that the two COT ANN controllers can control turbogenerators under steady state as well as transient conditions and thus allow turbogenerators to operate more closely to their steady state stability …

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About Resonant Modes At The Shielded Dielectric Hemisphere, Sergey Kharkovsky, A. E. Kogut, Z. E. Eremenko, V. V. Kutuzov, Yuri F. Filipov Jan 2000

About Resonant Modes At The Shielded Dielectric Hemisphere, Sergey Kharkovsky, A. E. Kogut, Z. E. Eremenko, V. V. Kutuzov, Yuri F. Filipov

Electrical and Computer Engineering Faculty Research & Creative Works

The resonant modes, which are excited at the shielded dielectric hemisphere, are investigated by the theoretical and experimental methods. The low-Q-factor modes of air cavity and high-Q-factor whispering gallery modes of dielectric structure are existed together in the case of high radial index value. The Q-factor value of the whispering gallery modes of the shielded dielectric sphere with the certain correlation between the sizes of dielectric hemisphere and metal shield can be more great than the Q-factor of the whispering gallery modes of the similar open dielectric resonator.

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A Robust Proportionate Affine Projection Algorithm For Network Echo Cancellation, T. Gansler, J. Benesty, Steven L. Grant, M. M. Sondhi Jan 2000

A Robust Proportionate Affine Projection Algorithm For Network Echo Cancellation, T. Gansler, J. Benesty, Steven L. Grant, M. M. Sondhi

Electrical and Computer Engineering Faculty Research & Creative Works

Echo cancelers which cover longer impulse responses (greater than or equal to 64 ms) are desirable. Long responses create a need for more rapidly converging algorithms in order to meet the specifications for network echo cancelers devised by the ITU (International Telecommunication Union). In general, faster convergence implies a higher sensitivity to near-end disturbances, especially "double-talk." Previously, a fast converging algorithm called the proportionate NLMS (normalized least mean squares) algorithm (PNLMS) has been proposed. This algorithm exploits the sparseness of the echo path in order to increase the convergence rate. A robust version of PNLMS has also been presented which …

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Advances Of Gyromagnetic Electronics For Emc Problems, Marina Koledintseva, L. K. Mikhailovsky, Alexander A. Kitaytsev Jan 2000

Advances Of Gyromagnetic Electronics For Emc Problems, Marina Koledintseva, L. K. Mikhailovsky, Alexander A. Kitaytsev

Electrical and Computer Engineering Faculty Research & Creative Works

A number of EMC problems at microwaves-detection and measurement of power (spectrum) of the signals and suppression of unwanted radiation-can be solved owing to the results obtained in the field of gyromagnetic (spin) electronics. The latter deals with the unique properties of gyromagnetic media (GM) based on microwave ferrites, including high-anisotropy hexagonal ferrites that do not need an intense magnetization field for their operation at ferromagnetic resonance. Approaches to the study of the interaction of GM with an electromagnetic field and ways of modeling frequency-selective measuring devices, absorbing coatings and all-mode filters of harmonics on the basis of GM are …

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Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson Dec 1999

Economic Dispatch And Optimal Sizing Of Battery Energy Storage Systems In Utility Load-Leveling Operations, Chin H. Lo, Max Darwin Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

Battery energy storage (BES) systems show promise of savings for both the utility and the customer. An algorithm combining multi-pass dynamic programming (MPDP) with a time-shift technique has been developed for two purposes: economic dispatch of BES and finding optimal BES power and energy capacities in a power system. Due to the daily cyclic nature of the load curve, a 168-hour load curve is decomposed into seven 24-hour subsections for easy management. Each subsection is treated independently. Decomposition can save computation time and computer memory. A time-shift technique provides better starting state values and improves the finding process of the …

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Analysis And Average-Value Modeling Of An Inductorless Synchronous Machine Load Commutated Converter System, J. T. Alt, Scott D. Sudhoff, B. E. Ladd Dec 1999

Analysis And Average-Value Modeling Of An Inductorless Synchronous Machine Load Commutated Converter System, J. T. Alt, Scott D. Sudhoff, B. E. Ladd

Electrical and Computer Engineering Faculty Research & Creative Works

Synchronous machine fed load-commutated converters (SMLCCs) are commonly used for dc power sources in marine and aircraft power systems. The focus of this paper is to set forth a model for SMLCCs for use in transient stability studies involving these systems. Although there has been considerable work in this area, much of this work has assumed the existence of a dc link inductor whereupon the dc link current is approximately constant. In practice, this filter is often eliminated, whereupon previous models are no longer valid. A new average-value model is set forth for SMLCCs in which there is no dc …

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Wide-Bandwidth Multi-Resolutional Analysis Of A Surface-Mounted Pm Synchronous Machine, S. D. Sudhoff, Jerry L. Tichenor, James L. Drewniak Dec 1999

Wide-Bandwidth Multi-Resolutional Analysis Of A Surface-Mounted Pm Synchronous Machine, S. D. Sudhoff, Jerry L. Tichenor, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Advances in power semiconductor devices have led to inverters with unprecedented voltage edge rates. This has decreased inverter switching losses and enabled the use of increasingly higher switching frequencies. However, faster edge rates and higher switching frequencies increase electromagnetic compatibility (EMC) problems, machine insulation stress, bearing currents, and other aspects of system design. Typical computer simulations used to design and evaluate proposed electric drive systems cannot be used to predict these high-frequency effects. A wide-bandwidth multi-resolutional analysis that allows designers to anticipate and quantify high-frequency effects is detailed in this paper. The approach is specifically applied to permanent magnet synchronous …

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