Engineering Commons^™

Adaptive Critic Based Optimal Neurocontrol For Synchronous Generator In Power System Using Mlp/Rbf Neural Networks, Jung-Wook Park, Ganesh K. Venayagamoorthy, Ronald G. Harley

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel optimal neurocontroller that replaces the conventional controller (CONVC),which consists of the automatic voltage regulator (AVR) and turbine governor, to control a synchronous generator in a power system using a multilayer perceptron neural network (MLPN) and a radial basis function neural network (RBFN). The heuristic dynamic programming (HDP) based on the adaptive critic design (ACD) technique is used for the design of the neurocontroller. The performance of the MLPN based HDP neurocontroller (MHDPC) is compared with the RBFN based HDP neurocontroller (RHDPC) for small as well as large disturbances to a power system, and they are …

Adaptive Critic-Based Neural Network Controller For Uncertain Nonlinear Systems With Unknown Deadzones, Pingan He, Jagannathan Sarangapani, S. N. Balakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

A multilayer neural network (NN) controller in discrete-time is designed to deliver a desired tracking performance for a class of nonlinear systems with input deadzones. This multilayer NN controller has an adaptive critic NN architecture with two NNs for compensating the deadzone nonlinearity and a third NN for approximating the dynamics of the nonlinear system. A reinforcement learning scheme in discrete-time is proposed for the adaptive critic NN deadzone compensator, where the learning is performed based on a certain performance measure, which is supplied from a critic. The adaptive generating NN rejects the errors induced by the deadzone whereas a …

An Expert System Architecture To Detect System-Level Automotive Emc Problems, Sreeniwas Ranganathan, Daryl G. Beetner, R. Wiese, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

Improving EMC in automobiles requires methods to detect potential problems early in the design process. Issues involved in the development of a system-level automotive EMC expert system are explored. The proposed system would help identify problems with radiation and immunity, crosstalk, placement of modules, component grounding and EMC testing. The architecture of the expert system has been developed. The system architecture is designed to allow rapid analysis of automobile designs, to point out potential problems and to suggest possible solutions.

An Improved Pnlms Algorithm, J. Benesty, Steven L. Grant

Electrical and Computer Engineering Faculty Research & Creative Works

The proportionate normalized least mean square (PNLMS) algorithm was developed for use in network echo cancelers. In comparison to the normalized least mean square (NLMS) algorithm, PNLMS has a very fast initial convergence and tracking when the echo path is sparse. Unfortunately, when the impulse response is dispersive, the PNLMS converges much slower than NLMS. This implies that the rule proposed in PNLMS is far from optimal. In many simulations, it seems that we fully benefit from PNLMS only when the impulse response is close to a delta function. We propose a new rule that is more reliable than the …

Comparison Of Heuristic Dynamic Programming And Dual Heuristic Programming Adaptive Critics For Neurocontrol Of 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 an optimal neurocontroller that replaces the conventional automatic voltage regulator (AVR) and the turbine governor for a turbogenerator connected to the power grid. The neurocontroller design uses a novel technique based on the adaptive critic designs (ACDs), specifically on heuristic dynamic programming (HDP) and dual heuristic programming (DHP). Results show that both neurocontrollers are robust, but that DHP outperforms HDP or conventional controllers, especially when the system conditions and configuration change. This paper also shows how to design optimal neurocontrollers for nonlinear systems, such as turbogenerators, without having to do continually online training of …

Counterexample Of A Claim Pertaining To The Synthesis Of A Recurrent Neural Network, Xindi Cai, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

Recurrent neural networks have received much attention due to their nonlinear dynamic behavior. One such type of dynamic behavior is that of setting a fixed stable state. This paper shows a counterexample to the claim of A.N. Michel et al. (IEEE Control Systems Magazine, vol. 15, pp. 52-65, Jun. 1995), that "sparse constraints on the interconnecting structure for a given neural network are usually expressed as constraints which require that pre-determined elements of T [a real n×n matrix acting on a real n-vector valued function] be zero", for the synthesis of sparsely interconnected recurrent neural networks.

Multilevel Voltage-Source Duty-Cycle Modulation: Analysis And Implementation, Keith Corzine, J. R. Baker

Electrical and Computer Engineering Faculty Research & Creative Works

Multilevel converters have become increasingly popular due to high power quality, high-voltage capability, low switching losses, and low electromagnetic compatibility concerns. Considering these advantages, the multilevel converter is a suitable candidate for implementation of future naval ship propulsion systems. This paper focuses on modulation techniques for the multilevel converter. In particular, a novel voltage-source method of multilevel modulation is introduced and compared to existing methods. The proposed method is discrete in nature and can therefore be readily implemented on a digital signal processor. The method is also readily extendable to any number of voltage levels. Results of experimental implementation are …

Estimating The Power Bus Impedance Of Printed Circuit Boards With Embedded Capacitance, Minjia Xu, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

Embedded capacitance is an alternative to discrete decoupling capacitors and is achieved by enhancing the natural capacitance between closely spaced power and return planes. This paper employs a simple cavity model to investigate the features affecting the power bus impedance of printed circuit boards with embedded capacitance.

Finite-Element Modeling Of Coaxial Cable Feeds And Vias In Power-Bus Structures, Hao Wang, Yun Ji, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents three different models that can be used to represent coaxial cable feeds or vias in printed circuit board power-bus structures. The probe model represents a coaxial feed or via as a current filament with unknown radius. The coaxial-cable model enforces an analytical field distribution at the cable opening or via clearance hole. The strip model employs the equivalent radius concept to represent cylindrical feeds and vias as rectangular strips. Although the strip model is functionally equivalent to two closely positioned probe models, it accurately represents the conductor radius and is more accurate in situations where the via …

Full Binary Combination Schema For Floating Voltage Source Multi-Level Inverters, X. Kou, Keith Corzine, Yakov L. Familiant

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents schema of operation for floating voltage source multi-level inverters. The primary advantage of the proposed schema is that the number of voltage levels (and thus power quality) can be increased for a given number of semiconductor devices when compared to the conventional "flying capacitor" topology. However, the new schema requires fixed floating sources instead of capacitors and therefore is more suitable for battery power applications such as electric vehicles, flexible AC transmission systems and submarine propulsion. Alternatively transformer/rectifier circuits may be used to supply the floating sources in a similar way to cascaded H-bridge inverters. Computer simulation …

High Q Shielded Dielectric Resonator -- The Basis Of Stable Mm-Waves Generator, V. V. Kutuzov, Sergey Kharkovsky, V. A. Solodovnik, K. A. Kutuzov

Electrical and Computer Engineering Faculty Research & Creative Works

High Q-factor whispering gallery modes which are excited in a shielded hemispherical dielectric resonator by an external signal or Gunn diode are investigated. Their application as modes of an oscillator with high frequency stability is proposed. The power of the output signal and frequency tuning of an oscillator based on the investigated resonator are measured.

Development Of A Program For Numerical Analysis Of Microwave Radio Links Under Different Conditions, M. Can, Sergey Kharkovsky

Electrical and Computer Engineering Faculty Research & Creative Works

Numerical analysis of system power budget is performed for radio link design and transmission planning purposes in cellular networks. The behavior of three different frequencies; 10.5 GHz, 23 GHz and 38 GHz is examined under the influence of such parameters like transmitter power output level, rain rate, fog density, distance, polarization type, antenna radius, temperature, foliage depth and etc. Received power levels are measured, calculated and reported for different radio link types and environmental conditions. A new program is developed in order to carry out system power budget analysis and design better microwave radio links. Measured and calculated values are …

Intelligent Control Of Turbogenerator Exciter/Turbine On The Electric Power Grid To Improve Power Generation And Stability, Ganesh K. Venayagamoorthy, Ronald G. Harley, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

A review of the applications of intelligent control to replace/augment the conventional excitation and/or turbine control of turbogenerators on the electric power grid is presented in the paper. The intelligent controller designs are based on neural networks and adaptive critic designs (ACDs). The feedback variables are completely based on local measurements from the generators. Simulations and some practical laboratory implementations on a single-machine-infinite-bus and a three-machine power system demonstrate that intelligent controllers are much more effective than the conventional PID control for improving dynamic performance and stability of the power grid under small and large disturbances. The safety margins on …

Comparison Of Mobility Method And Mass Conservation Method In A Study Of Dynamically Loaded Journal Bearings, Biao Yu, Jerzy T. Sawicki

Mechanical Engineering Faculty Publications

The inverse problem of dynamically loaded journal bearings was solved using generalized Reynolds equation coupled with a complete mass conservative cavitation boundary conditions, as outlined by the Jacobsson-Floberg and Olsson (JFO) cavitation theory. In the course of solution, the modified Thomas algorithms was employed, instead of standard Gauss±Jordan reduction method, which fully utilizes the sparse character of the system matrix, and thus greatly reduces computational time. The developed model was tested against the well-known mobility method for the case of journal bearings in a commercial reciprocating air compressor. It was found that the mobility method overestimates minimum film thickness and …

Water Transport In Polymer Electrolyte Membrane Electrolyzers Used To Recycle Anhydrous Hcl: I. Characterization Of Diffusion And Electro-Osmotic Drag, Sathya Motupally, Aaron J. Becker, John W. Weidner

Faculty Publications

In this paper, diffusion and electro-osmotic drag of water across Nafion® membranes in the presence of HCl are characterized. For all the measurements, one side of the Nafion membrane was in contact with liquid water and the other side with gaseous anhydrous HCl. To characterize diffusion of water, the open-circuit flux of water across a catalyst-coated Nafion 115 membrane was measured as a function of HCl flow rate and temperature at a constant cell pressure of 1 atm. Due to the nature of varying driving force for diffusion as a function of HCl flow rate, the experimental data was analyzed …

Development Of A Novel Co Tolerant Proton Exchange Membrane Fuel Cell Anode, Andrew T. Haug, Ralph E. White, John W. Weidner, Wayne Huang

Faculty Publications

Typically Pt is alloyed with metals such as Ru, Sn, or Mo to provide a more CO-tolerant, high-performance proton exchange membrane fuel cell (PEMFC) anode. In this work, a layer of carbon-supported Ru is placed between the Pt catalyst and the anode flow field to form a filter. When oxygen is added to the fuel stream, it was predicted that the slow H₂ kinetics of Ru in this filter would become an advantage compared to Pt and Pt:Ru alloy anodes, allowing a greater percentage of O₂ to oxidize adsorbed CO to CO₂. With an anode feed …

Studies On Capacity Fade Of Spinel-Based Li-Ion Batteries, Ramadass Premanand, Anand Durairajan, Bala Haran, Ralph E. White, Branko N. Popov

Faculty Publications

The performance of Cell-Batt^® Li-ion cells using nonstoichiometric spinel as the positive electrode material has been studied at different charging rates. The capacity of the cell was optimized based on varying the charging current and the end potential. Subsequent to this, the capacity fade of these batteries was studied at different charge currents. During cycling, cells were opened at intermittent cycles and extensive material and electrochemical characterization was done on the active material at both electrodes. For all charge currents, the resistance of both the electrodes does not vary significantly with cycling. This result is in contrast with cells …

Modeling The Effects Of Ion Association On Alternating Current Impedance Of Solid Polymer Electrolytes, Changqing Lin, Ralph E. White, Harry J. Ploehn

Faculty Publications

This work presents a rigorous continuum model describing the transport of ions and associated ion pairs in solid polymer electrolytes subjected to small amplitude alternating current (ac) excitation. The model treats ion association as a reversible reaction among ions and ion pairs. Dimensionless governing equations are developed from component mass balances, flux equations based on dilute solution theory, and the Poisson equation. Assuming reversible electrode reactions and electroneutrality, the model equations have an analytical solution. Further simplifications are possible in limiting cases (weak and strong association, zero and infinite frequency excitation), giving expressions consistent with previously published models. We use …

Evolutionary Algorithms For Multiobjective Evaluation Of Watershed Management Decisions, Misgana K. Muleta, John W. Nicklow

Civil and Environmental Engineering

The comprehensive and systematic management of watersheds is essential for reducing the adverse environmental impacts arising from anthropogenically caused erosion and subsequent sedimentation. This paper describes a computational methodology that is designed to serve as a watershed decision support system and is capable of controlling environmental impacts of non-point source pollution resulting from erosion. In the decision process, the methodology also accounts for other inseparable objectives such as economics and social dynamics of the watershed. This decision support tool was developed by integrating a comprehensive hydrologic model known as SWAT and state-of-the-art multiobjective optimization technique within the framework of a …

Development And Application Of Streakline Visualization In Hypervelocity Flows, P. Lemieux, H. G. Hornung

Mechanical Engineering

A method for visualizing streaklines in hypervelocity flows has been developed. The method uses the high temperatures produced in hypervelocity flows to ablate small amounts of sodium deposited onto a wire stretched across the flow and to broaden the lines in the sodium spectrum. By using a dye laser, tuned to a wavelength close to one of the sodium D-lines, as the light source in shadowgraph or Schlieren visualization, streaklines seeded with sodium become visible through absorption and/or enhanced refractivity. The technique has been used to investigate the stability of the shear layer produced by the curved bow shock on …

A Venture Capital Fund For Undergraduate Engineering Students At Rowan University, Anthony J. Marchese, John C. Chen, John L. Schmalzel

Mechanical Engineering

All engineering students at Rowan University are required to take the 8-semester Engineering Clinic sequence wherein multidisciplinary student teams engage in semester-long design projects. In addition to projects that are funded by local industry, faculty research grants or departmental budgets, a Venture Capital Fund has been created, which is specifically ear-marked for the development of original student inventions. Funding of up to $2500 per student team per semester is competitively awarded based on student-generated proposals to the Venture Capital Fund, which has been created through a series of grants from the National Collegiate Inventors and Innovators Alliance (NCIIA). To qualify …

Design And Analysis Of Class Ab Rf Power Amplifier For Wireless Communication Applications, Mohamed El-Dakroury

Retrospective Theses and Dissertations

The Power Amplifier is the most power-consulting block among the building blocks of RF transceivers. It is still a difficult problem to design power amplifiers, especially for linear, low voltage operation. Until now power amplifiers for wireless applications is being produced almost in GaAs processes with some exceptions in LDMOS, Si BJT, and SiGe HBT. The submicron CMOS processes for power amplifiers are under research focus since CMOS offers integration for power amplifier with rest of the transceivers blocks due to its high yield. Also CMOS process is cheap.

This thesis report details the design process of a class AB …

High Frequency Communication System Modeling And Performance Enhancement, Employing Novel Adaptive Dsp Techniques, Murad M. Qahwash

Retrospective Theses and Dissertations

High Frequency (HF) communication has been shown to be a useful communication technique from the very beginning of World War I and it accelerated during World War II. This is attributed to its simplicity, ability to provide near globe connectivity at low power without repeaters, moderate cost, and ease of proliferation [1]. In fact, the HF communication system utilizes the ionosphere [2][3][4] to refract the skywave signals to a distant receiver. This ionospheric channel has some disadvantages. First, it is a non-stationary channel as the HF frequency propagation is a function of the sun spot activities, solar winds, and diurnal …

Design And Operation Of A Pilot Plant For Biodiesel Production From Triglycerides, Balasubramaniam Karthikeyan

Masters Theses

"In the wake of the events of September 11th 2001, the quest to relieve the nation’s dependence on petroleum fuels have taken a new urgency, there is a renewed interest in use of renewable biogenic fuels in particular -- the “biodiesel.” Biodiesel generally refers to fatty acid methyl esters of monohydric alcohols -- predominantly the methyl alcohol.

The principal sources of fatty acids are vegetable oils - soybean oil and canola oil. However, there are other “cheaper” sources of fatty acids that include beef tallow, poultry fats, pork fats and the used cooking oils. The first two are available in …

The Causes Of Armature Surface Fracturing Within Helical Flux-Compression Generators, Jason Baird, Paul Nicholas Worsey

Mining Engineering Faculty Research & Creative Works

Aluminum and copper tubes filled with explosive were tested during this study of high strain rate effects, as an adjunct to helical flux-compression generator research at the University of Missouri-Rolla, directly affecting the understanding of flux cutoff and high strain-rate changes in generator armatures. Longitudinal cracks characteristically developed in the outer surface of armatures at a smaller expansion ratio than predicted. These cracks occurred within two diameters of the detonator end of the armature but did not extend when the tubing expanded under explosive pressurization. Such cracks appear to cause magnetic flux cutoff, and flux losses seriously affect energy conversion …

Nebraska Summary: S340 New Holland Tm130, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Summary: S429 Case-Ih Mxm 120, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Tests 2031 & 2055: Case Ih Jx 85 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 2100: Mccormick Mtx 155 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1812: Challenger Mt755 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.