Electrical and Electronics Commons^™

The Control Of Rotor Side And Grid Side Converters In A Dfig During Network Voltage Unbalance Conditions Using Resonant Current Controllers., Joseph Kearney, Michael Conlon, Eugene Coyle

Conference papers

This paper implements control techniques to enable improved operation of DFIG’s when subjected to the effects of network voltage unbalance conditions. The control scheme involves the integration of a resonant regulator into the PI controllers of both the rotor side and grid side converters in a DFIG. The resonant controller is tuned to twice the network frequency (2ω_e) and designed to mitigate against the oscillations in a DFIG due to network voltage unbalance conditions. The grid side converter controller also incorporates a second resonant controller tuned to three times the grid frequency (3ω_e) to alleviate the …

Novel Ac Side P&O Maximum Power Transfer Control For Grid Connected Photovoltaic Systems, Mohamed Moin Hanif, Malabika Basu, Kevin Gaughan

Conference papers

Grid connected Photovoltaic inverters can convert PV energy into electricity with very high efficiencies. Power from the PV panels fluctuates depending on various weather conditions. PV inverters usually include a maximum power point tracker (MPPT) to track this varying power, in order to transfer all the available power to the grid efficiently. Control of power transferred to the grid along with the MPPT plays a crucial role in determining the efficiency of a PV system. This paper discusses about the basic power transfer theory between sources (PV and Grid) and focuses on the need of a DC-DC boost circuit, along …

Switching Circuit For A Permanent Magnet Dc Motor, Alex Boatman

Electrical Engineering

The project is a circuit that will basically supply current from the battery to the different stator coils at opportune moments. With a hall-effect sensor on the shaft as a feedback to a microcontroller, I was able to toggle switches based on the position of the shaft at the moments where we would be using as little power as possible. The operation of the control circuit works similar to a stepper motor; it takes a signal from the microcontroller that is sent to some FET drivers, which in turn sends signals to the FETs to open or close as the …

Dc-Dc Converter For Harvesting Energy From An Exercise Bike, Henry Ureh, Chris Henry

Electrical Engineering

Create an efficient buck-boost converter that adapts to input voltage range from ~3.8V to 70V, and outputs 13.7V DC, the voltage required by a charge controller to charge a battery. The energy stored in the battery will be supplied back to the grid.

The cost of energy saved by the converter should eventually cover the initial price of the converter. The converter should help reduce the net power consumption of the exercise machines used in the Cal Poly gym

The Integrated Control Of The Rotor Side And Grid Side Converters In A Dfig To Reduce Both Power And Torque Pulsations During Network Voltage Unbalance Conditions., Joseph Kearney, Michael Conlon, Eugene Coyle

Conference papers

No abstract provided.

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …

Low Power Fft Processor Design Considerations For Ofdm Communications, David Layne Rushforth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Today's emerging communication technologies require fast processing as well as efficient use of resources. This project specifically addresses the power-efficient design of an FFT processor as it relates to OFDM communications such as cognitive radio. The Fast Fourier Transform (FFT) processor is what enables the efficient modulation in OFDM. As the FFT processor is the most computationally intensive component in OFDM communication, the power efficiency improvement of this component can have great impacts on the overall system. These impacts are significant considering the number of mobile and remote communication devices that rely on limited battery-powered operation. This project explores current …

Characterization Of Hardening By Design Techniques On Commercial, Small Feature Sized Field-Programmable Gate Arrays, Thomas E. Simmons

Theses and Dissertations

In this thesis, a methodology is developed to experimentally test and evaluate a programmable logic device unde r gamma irradiation. The purpose of which is to determine the radiation effects and characterize the improvements of various hardening by design techniques. The techniques analyzed in this thesis include Error Correction Coding (ECC) and Triple Modular Redundancy (TMR). The TMR circuit includes three different functional implementations of adders compared to TMR voted circuits of those same adders. The TMR is implemented with the same functional adders and as a Functional TMR (FTMR) with three different function adders that are voted on. The …

Power Generation By Harvesting Ambient Energy With A Micro-Electromagnetic Generator, James H. Shields

Theses and Dissertations

This thesis investigated the potential power output of a micro-electromagnetic generator fabricated using typical microfabrication materials and techniques. The design was based on a desire to free bio-implanted or remote electronic devices from batteries and their finite power supplies. A micro-electromagnetic generator could harvest energy from the ambient environment and power such devices indefinitely. Designs for the stator coil and rotor magnet components of the generator were optimized to produce maximum current density based upon electromagnetic theory. The relative orientation of the coil to the rotor and material selection for each component were considered. Coils were fabricated using low-resistance gold. …

Analysis And Design Of Continuous Input Current Multiphase Interleaved Buck Converter, Sean Michael Zich

Master's Theses

The power requirements for microprocessors have been increasing per Moore's Law. According to International Technology Roadmap (ITRS), Voltage Regulator Module (VRM) for microprocessors will be about 200 W at 1 V output in 2010. With the VRM’s topology of synchronous buck, serious technical challenges such as small duty cycle, high switching frequencies, and higher current demands, contribute to decreased power density and increased cost.

This thesis proposes a Continuous Input Current Multiphase Interleaved Buck topology to solve the technical challenges of powering future microprocessors. This new topology is aimed to improve past topologies by providing continuous input current and improved …

A Systematic Study On Structural And Optical Properties In Conjugated Polymer Photovoltaic Devices, Sri Sabarinadh Sunkavalli

Electrical & Computer Engineering Theses & Dissertations

Conjugated polymer/fullerene based solar cells represent an exciting alternative to inorganic ones because of their low production costs, flexibility and low weight. At present, commercialization of organic photovoltaic (OPV) cells is limited due to their relatively low efficiency in comparison to silicon ones. In order to understand the operation of OPV cells and to increase their efficiency, more information about the structure of the absorber layer is needed. In particular, the connection between structure and properties of the absorber layer is of great importance. Performance of bulk heterojunction organic solar cells based on poly (3-hexylthiophene) as donor and a soluble …

Control Of Double Fed Induction Generator Wind Turbine During Network Voltage Unbalance Conditions, Joseph Kearney, Michael Conlon

Conference papers

The behaviour of Double-Fed Induction Generators to supply network voltage unbalance is investigated. The paper describes a method to control the rotor-side converter in a DFIG when subjected to the effects of network voltage unbalance conditions. A parallel control scheme is implemented to control the positive and negative sequence components independently. A DFIG model is implemented in Matlab/Simulink and simulations show the reduction in power and torque oscillations and a reduction in the high unbalanced currents generated as a result of the applied voltage unbalance.

Significance Of Logic Synthesis In Fpga-Based Design Of Image And Signal Processing Systems, Mariusz Rawski, Henry Selvaraj, Bogdan J. Falkowski, Tadeusz Luba

Electrical & Computer Engineering Faculty Research

This chapter, taking FIR filters as an example, presents the discussion on efficiency of different implementation methodologies of DSP algorithms targeting modern FPGA architectures. Nowadays, programmable technology provides the possibility to implement digital systems with the use of specialized embedded DSP blocks. However, this technology gives the designer the possibility to increase efficiency of designed systems by exploitation of parallelisms of implemented algorithms. Moreover, it is possible to apply special techniques, such as distributed arithmetic (DA). Since in this approach, general-purpose multipliers are replaced by combinational LUT blocks, it is possible to construct digital filters of very high performance. Additionally, …

Analysis Of A Variable Speed Double-Fed Induction Generator Wind Turbine During Network Voltage Unbalance Conditions., Joseph Kearney, Michael Conlon

Conference papers

The behaviour of Double-Fed Induction Generators to supply network voltage unbalance is investigated. The paper shows the effects that voltage unbalance can have on a DFIG, using Matlab/Simulink. The results from simulations show that voltage unbalance affects both the induction generator and the rotor converter, due to the high unbalanced currents generated. The ability to modify the control strategy of a DFIG to compensate for voltage unbalance is outlined and simulations show the improvements to the performance of the DFIG.

Socio-Economic Impacts Of Computer Viruses In Tanzania, M Victor

Tanzania Journal of Engineering and Technology (TJET)

This paper reports on a research project conducted with an objective of identifying and assessing various approaches used by different computer users (Management, System Administrators and end users) in Tanzania to combat computer viruses (CVs), and to assess users' awareness level on CVs. Specifically, the study aimed at assessing the awareness level on CVs to the Tanzanian business community; analyze the socio -economic impact caused by CVs in Tanzania and; assess existing methods, capacity and limitations on controlling CVs in Tanzania. Data was collected using both questionnaires and interview from financial institutions such as NBC and BOT, and telecommunications sector …

Microbubble-Based Model Analysis Of Liquid Breakdown Initiation By A Submicrosecond Pulse, J. Qian, R. P. Joshi, K. H. Schoenbach, J. Dickens, A. Neuber, M. Butcher, M. Cevallos, H. Krompholz, E. Schamiloglu, J. Gaudet

Electrical & Computer Engineering Faculty Publications

An electrical breakdown model for liquids in response to a submicrosecond(∼100ns) voltage pulse is presented, and quantitative evaluations carried out. It is proposed that breakdown is initiated by field emission at the interface of pre-existing microbubbles. Impact ionization within the microbubble gas then contributes to plasma development, with cathode injection having a delayed and secondary role. Continuous field emission at the streamer tip contributes to filament growth and propagation. This model can adequately explain almost all of the experimentally observed features, including dendritic structures and fluctuations in the prebreakdown current. Two-dimensional, time-dependent simulations have been carried out based on a …

Review Of The Product Development Process And Information Flow In The Manufacturing Industry: Problems And A Possible Wav Forward, E Opiyo

Tanzania Journal of Engineering and Technology (TJET)

No abstract provided.

Load Flow Solution For Three-Phase Mv Radial Distribution Connected Network Supplying Different Line Topologies, B. J. Kundy

Tanzania Journal of Engineering and Technology (TJET)

In this paper, a load flow solution for the Medium Voltage (MV) three-phase radial distribution in delta-delta (Δ–Δ) connected network supplying different line topologies such as three phase, phase to phase and single-wire earth return (SWER) networks is presented. The general voltage related network equations are developed using Kirchhoff’s voltage and current laws. Development of a solution to the load flow analysis applying the developed general voltage related network equations is proposed in order to evaluate the network voltage profile. Various numbers of arrays are developed for the identification of the network under study. The proposed method is a new …

Application Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Arton Of Vibrational Techniques In Determination Of Dynamic Properties Of Agricultural Products-State Of The Art, Silas Kajuna

Tanzania Journal of Engineering and Technology (TJET)

Vibration is one of the techniques employed in the determination of dynamic properties of fruits and vegetables. It entails generation of a mechanical or acoustic vibrational signal which is propagated through the flesh of the agricultural material. A transducer is either attached or held close to the specimen to monitor the propagation of the signal through the specimen. The manner in which the signal is transmitted through the material is analyzed, and the dynamic properties of the specimen which relate to its firmness or its internal being are derived. The technique has been around for the past 30 years or …

Field Enhancement In Silicon Nanotip Field Emitter Arrays, Ajith Varghese

Electrical & Computer Engineering Theses & Dissertations

No abstract.

Resonant Tank Motor Model For Voltage Reflection Simulations With Pwm Drives, Davia W. Schlegel, Glenn T. Wrate, Russ Kerkman, Gary Skibinski

Conference Papers in Published Proceedings

Reflected wave transient voltages that are impressed on drive output cables and low voltage AC induction motors are normally simulated with steep fronted dv/dt pulse waveforms from PWM voltage source inverters. System simulation arises from a need to correlate reflected wave peak voltage and risetime with the dielectric insulation capability of both the motor and cable. To obtain reasonable results, accurate models of each component must be employed. This investigation concentrates on parameter identification for a high frequency resonant tank motor model from fractional to several hundred horsepower.

Development And Testing Of An Ac Micro Hollow Cathode Simulator, Thomas E. Caldwell

Electrical & Computer Engineering Theses & Dissertations

The use of AC source plasma discharge devices in applications such as material processing and film deposition has increased in recent years due to improvements in discharge efficiency made possible by devices such as the micro hollow cathode. Designing hollow cathodes for specific applications requires an understanding of the processes that govern the discharge. Simulation is an inexpensive tool for understanding hollow cathode operation and optimizing the device for specific applications. This thesis describes the development of an AC micro hollow cathode simulator. It details the theoretical models used in the simulation and presents the results of test cases intended …

Micro Hydro Power, Frederick J. Munster

Maine Collection

Micro Hydro Power

by Frederick J. Munster

Department of Economic and Community Development, August, Me. 1999 (?).

Contents: Introduction / History of Hydropower in Maine / Renewables / Why Micro Hydro / Determining Flow / Determining Head / Estimating Energy Potential / Hydro Turbines / Dams, Impoundments, Penstocks and Power Houses / Utility Interconnected Systems / Battery Charging Systems / Operation and Maintenance / Economics / Regulation of Hydro Development / For More Information / References

Two Dimensional, Time Dependent Modeling And Simulation Of Semi-Insulating Gaas High-Power Photoconductive Switches, Prakasit Kayasit

Electrical & Computer Engineering Theses & Dissertations

The current-voltage (I-V) characteristics and photoconductive behavior of semi-insulating GaAs (SI GaAs) high-power switches have been investigated by using a two-dimensional, time dependent, drift diffusion transport model. The dc current-voltage behavior as predicted by the results of this model was compared with available experimental data to evaluate the accuracy and validity of the model. The results show very good agreement, Next, research was carried out to investigate the behavior of the switches under high-field operation.

Simulations at high voltages emphasize on the two following processes: (a) The mechanism of impact ionization and the effect of this mechanism on device stability …

Electrical Characteristics And Parallel Operation Of Microhollow Cathode Discharges, Wenhui Shi

Electrical & Computer Engineering Theses & Dissertations

This thesis describes the electrical properties of microhollow cathode discharges with argon as filling gas. The appearance and current-voltage characteristics of microhollow cathode discharges have been recorded. Three kinds of discharge modes (predischarge, hollow cathode discharge and abnormal discharge) have been observed. The range of operation of the hollow cathode discharge has been found to be 0.5 < pD & 5 Torr cm in argon. By reducing the hole diameter to 100 pm, we were able to operate the discharge to atmospheric pressure in a dc mode. The possibility of dc parallel operation of microhollow cathode discharges was explored. Parallel operation could be obtained without individual ballast for discharges with a positive I-V slope greater than 10 V/mA over a voltage range of more than 5 % of the sustaining voltage. For parallel operation outside the range the ballasting is required. This model was explored by using a segmented anode model. The result of the simple calculation coincides well with the experiment result, where a semi-insulator silicon was used as distributed ballast.

Fuel Cells, Frederick J. Munster Jr.

Maine Collection

Fuel Cells

by Frederick J. Munster Jr.

Edited by: Mr. Christopher Carroll

Maine Department of Economic Development, Augusta, Maine, 1998.

Contents: Hydrogen / Hydrogen Safety / Electrolysis / Electrolyzers / History of Fuel Cells / How Fuel Cells Operate / Fuel Cell Types / Fuel Cell Electrochemistry / Power Systems / Fuel Cells in Transportation / Hydrogen Powered Internal Combustion Engines / Home, Garden, Education and Industry / For More Information / Glossary / References

An Appraisal Of Electricity Supply In Nigeria And The Privatisation Option, E. I. K. Sule, C. M. Anyanwu

CBN Occasional Papers

Incessant electric power cuts in most parts of the country has become a normal feature of electricity supply throughout Nigeria. The power outages cause much inconvenience and economic losses to all and sundry. This study has shown that the most critical factor behind the incessant power failure is the problem of inadequate funding of the industry at a time it was forced to accommodate rapid expansion. Other factors include lack of autonomy, inefficiency, poor organization as well as lack of skilled manpower. The paper has examined these problems on the basis of which suggestions are made on how the worrisome …

The Effects Of Channel Curvature And Protusion Height On Nucleate Boiling And The Critical Heat Flux Of A Simulated Electronic Chip, John E. Leland

Office for Research Publications and Presentations

The quest for higher power yet smaller electronics has given rise to the need for very effective cooling of these electronics. Because one of the foremost problems in electronics cooling is achieving high heat flux cooling within small packages while expending minimal pumping power, one focus of this study was to investigate the effects of channel curvature on the CHF. Experimental data were obtained for flow rates of 1-7 m/s, subcoolings of 5-35"C, and radii of curvature of 25.4 and 50.8 mm. A correlation was obtained for these data which provided an excellent fit.

One condition that has been ignored …

Plains Electric Members Service Area_04-29-1994, University Of New Mexico Bureau Of Business And Economic Research

BBER Publications

This report presents historical and projected socioeconomic data for 19 New Mexico and two Arizona counties which comprise the service areas of the distribution cooperatives in the Plains Electric Generation and Transmission Cooperative, Inc., system.

Low‐Cost Technique For Preparing N‐Sb2S3/P‐Si Heterojunction Solar Cells, O. Savadogo, K. C. Mandal

Faculty Publications

No abstract provided.