Power and Energy Commons^™

Validated Real-Time Energy Models For Small-Scale Grid-Connected Pv-Systems, Lacour Ayompe, Aidan Duffy, Sarah Mccormack, Michael Conlon

Articles

This paper presents validated real-time energy models for small-scale grid-connected PV-systems suitable for domestic application. The models were used to predict real-time AC power output from a PV system in Dublin, Ireland using 30-min intervals of measured performance data between April 2009 and March 2010. Statistical analysis of the predicted results and measured data highlight possible sources of errors and the limitations and/or adequacy of existing models, to describe the temperature and efficiency of PV-cells and consequently, the accuracy of power prediction models. PV-system AC output power predictions using empirical models for PV-cell temperature and efficiency prediction showed lower percentage …

Simulation Of Temperature Distributions In Tissue Upon Laser Pulse Irradiation Including Water Mass Transfer, Deepthi Nagulapally

Electrical & Computer Engineering Theses & Dissertations

Lasers, due to their unique characteristics, have tremendous applications in the medical field. Generally all laser applications in hie-medicine involve the propagation of laser energy through tissue. Energy is deposited giving rise to many physical, hie-chemical, and mechanical effects. Among these are dynamical changes in the local temperature distributions within the tissue. Analysis of the temperature changes requires the creation of an appropriate optical transmission and heat flow model that incorporates user specified laser parameters. Here, a numerical simulation model was developed to study both steady state and time dependent temperature distributions due to pulsed laser radiation within user specified …

Further Developments On The Geothermal System Scoping Model, Mark Antkowiak, Rosemary Sargent, Jesse W. Geiger

Publications (E)

The fields of well construction and engineering, power plant construction and engineering, and reservoir engineering often proceed independently of one another. Yet the subsystems of a geothermal plant with which each of these fields is concerned need to be integrated in order to create a viable geothermal power system and make enhanced (or engineered) geothermal systems (EGS) a technical and an economic reality. Furthermore, each of these subsystems need to be examined in the context of the overall power system to aid with plant construction, and–more salient to the U.S. Department of Energy–to help determine best investment of research dollars. …

A Comparison Of Induction Motor Starting Methods Being Powered By A Diesel-Generator Set, Adam John Wigington

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Starting induction motors on isolated or weak systems is a highly dynamic process that can cause motor and load damage as well as electrical network fluctuations. Mechanical damage is associated with the high starting current drawn by a ramping induction motor. In order to compensate the load increase, the voltage of the electrical system decreases. Different starting methods can be applied to the electrical system to reduce these and other starting method issues. The purpose of this thesis is to build accurate and usable simulation models that can aid the designer in making the choice of an appropriate motor starting …

The Applications And Limitations Of Printable Batteries, Matthew Delmanowski

Graphic Communication

This study focuses on the potential applications for printed batteries and how they could affect the printing industry. It also analyzes the main problems associated with manufacturing this technology and what needs to be done to overcome these issues. To find the answers to these questions, two methods of research were used. The first was through the elite and specialized interviewing of Dr. Scott Williams of Rochester Institute of Technology and Professor Nancy Cullins from Cal Poly. The second form of research was a common, yet useful, method called secondary research. This entailed looking at recent written research papers about …

Simulation Of Cal Poly Super System Simulink Model Using Insolation Variation, Jacob Kory

Electrical Engineering

This senior project focuses on simulation of the Cal Poly SuPER system using an insolation model. First, local and historical weather data is examined to determine the range of limits that the model will utilize. Then, the insolation model is constructed to fit into the existing SuPER model. The overall system is tested under a variety of insolation values to determine system performance of motor and static loads. Based on these simulations, several factors of the current model are discovered that limit the power consumption profile under off-peak load conditions. Finally, recommendations on improvements to the model are discussed

Distributed Generation: Issues Concerning A Changing Power Grid Paradigm, Scott G.M. Therien

Master's Theses

Distributed generation is becoming increasingly prevalent on power grids around the world. Conventional designs and grid operations are not always sufficient for handling the implementation of distributed generation units; the new generation may result in undesirable operating conditions, or system failure. This paper investigates the primary issues involved with the implementation of distributed generation and maintaining the integrity of the power grid. The issues addressed include power flow, system protections, voltage regulation, intermittency, harmonics, and islanding. A case study is also presented to illustrate how these issues can be addressed when designing distributed generation installation on an existent distribution system. …

Optimization Of P3ht-Pcbm Polymer Solar Cells Through Device Simulation And Manufacturing, James Boom

Computer Engineering

Given a good model and implementation of that model, computer simulation can be used to reduce the time and material costs of research. To this end I worked with other students to manufacture, test and simulate the single layer P3HT-PCBM solar cell. Using the data collected from this project, future work can then be done with the project's simulator to further optimize these types of solar cell devices.

Power Losses Associated With Stand-By Chargers, Robert Peralta

Electrical Engineering

Many average households across the United States may not realize how much power is saved by simply removing the plug from the receptacle when not being used. A misconception with stand-by/portable chargers is; if a device is not connected to the charger, but the charger is still connected to the wall, then the charger will not consume power. That statement is false. The following report will demonstrate how much power is lost in an average household. When a reference is made to an average house, I will refer to a 4 bedroom single family home. The house will have an …

Electric Bicycle System, Robert Cong, Rodney Martinez, Mark Casilang, Peter Vong

Electrical Engineering

The Electric Bicycle System is a systems project that incorporates three different ways of charging a lithium-ion battery: the 120VAC wall outlet, regenerative braking, and solar power; which is used to power an electric hub motor running a bicycle. The purpose of the project is to show that it is possible and relatively simple, to build an electric bicycle by oneself. This project can be broken down into five separate categories: the lithium-ion battery, the DC-DC boost converter, the solar panel, the motor, and the motor controller. Each of these will be built upon and improved further by future students, …

Transmission Line Forecast Study, Ryan Garoogian

Electrical Engineering

Load forecasting is the procedure to predict future loading conditions on a power system. Using simulation software such as ETAP you are able to predict abnormal voltage conditions, overloading of certain equipment, as well as determine protective equipment from short circuit studies. This study consisted of a 115kV loop network with multiple loading busses and one infinite bus. There was no separate generation other than the infinite bus. As load increased from forecasting to the future voltage dropped. To restore voltage levels capacitors were added at strategic points in the system to boost the voltage back up. Preparing yourself for …

High Voltage Switched-Mode Power Supply For Three-Phase Ac Aircraft Systems, John Brewer Jr., Kamaljit Bagha

Electrical Engineering

The purpose of this senior project was to design and fabricate a proof-of-concept Three-Phase Sinusoidal Switched-Mode Inverter with a power output capability of 10 kW and nominal operating frequency of 400 Hz for AC aircraft system applications. This senior project report includes a thorough discussion and presentation of the inverter system background, requirements, design, construction, and testing processes.

Energy Harvesting From Exercise Machines Cal Poly Recreation Center Implementation, Justin Arakaki, Praveen Lawrence, Audrey Nakamura

Electrical Engineering

As Cal Poly moves towards an environmentally friendly campus, the Energy Harvesting from Exercise Machines (EHFEM) project looks to generate a new source of renewable energy to help power the Cal Poly Recreation Center. The project focuses on retrofitting exercise machines to generate electricity. As of December 2009, Audrey Nakamura, Justin Arakaki, and Praveen Lawrence developed a design which allows the contribution of electricity generated from multiple exercise machines into the power grid.

The project will require an investigation of retrofitted machine designs by Cal Poly students and commercially available products and systems. The information obtained from the product research …

Energy Harvesting From Exercise Machines: Bike Buck-Boost Converter, Monroe Diamond, Brian Vuong

Electrical Engineering

This project is a continuation of previous senior projects’ work on Energy Harvesting from Exercise Machines (EHFEM). EHFEM seeks an alternative DC to DC converter to function within the existing exercise bike system. Implementing this new DC to DC converter aims to avoid previous complications other groups encountered, such as only running at low load currents, exceeding an input threshold voltage to begin operation, and performing at low efficiency. In developing this self‐generating exercise bike, Cal Poly wishes to incorporate an array of energy‐harvesting exercise machines in its Recreation Center expansion scheduled for completion in 2012.

An Expandable Micromotor Dc Drive System, Michael Ruelan, Justin Gragg

Electrical Engineering

This report documents the design phases and fabrication of an expandable micro-motor DC drive system. This project illustrates that a flexible range of output power demands can be met from a small DC micro-motor drive unit with the use of power electronics.

In this project miniature DC micromotor drives, each capable of drawing up to 5.5 amps rated current (5 amps due to the utilization of a 5 amp fuse), were designed as card inserts that can be conveniently inserted in parallel in to a cardholder within the console. The “insert” feature allowed our console to successfully draw up to …

Magnetic Design Web Application, Michael Brim

Electrical Engineering

The automated Magnetic Design Web Application, available at http://www.magneticdesign.org, generates the full design process of a power transformer, gapped inductor and toroidal inductor given design specifications provided by the user. Calculations are accomplished using Area Product, Ap, or Core Geometry, Kg, procedures. All design processes mirror the format used in Dr. Taufik’s Introduction to Magnetic Design lecture-notes. An administrative backend is provided where instructors can add or modify core design values to expand the array of materials used. The project aims to aid student understanding of magnetic design and course concepts while allowing instructors to broaden the scope of material …

Pulse Density Modulated Soft Switching Cycloconverter, Jesse Timothy Adamson

Master's Theses

Single stage cycloconverters generally incorporate hard switching at turn on and soft switching at turn off. This hard switching at turn on combined with the slow switching speeds of thyristors (the switch of choice for standard cycloconverters) limits their use to lower frequency applications.

This thesis explores the analysis and design of a pulse density modulated (PDM), soft switching cycloconverter. Unlike standard cycloconverters, the controller in this converter does not adjust thyristor firing angles. It lets only complete half cycles of the input waveform through to the output. This allows and requires a much greater frequency step down from the …

Development Of A 12 Kva Dsp-Controlled Laboratory Prototype Upqc, Iurie Axente, Jayanti Navilgone Ganesh, Malabika Basu, Michael Conlon, Kevin Gaughan

Articles

This paper reports the development of a laboratory prototype of a fully digital DSP-controlled 12-kVA unified power quality conditioner (UPQC), capable of compensating for both the supply voltage and the load current imperfections. A fully digital controller based on the TMS320F2812 DSP platform is implemented for the reference generation as well as control purposes. The delay problem in the digital controller is overcome by application of a fast DSP, a compact control technique and proper flow of control steps in the DSP software. A phase-locked loopless software grid synchronization method has been implemented for the effective operation of the UPQC …

Air Piston Approach To Wave Power Generation, Arun Ramadass

Theses

Scientists have calculated that, by tapping just 0.2% of the energy produced by the world's oceans we can provide for all the worlds current energy needs. It is generally accepted that a combination of traditional energy production methods, (oil, coal, gas, nuclear) mixed with a combination of renewable energy production approaches is the future in providing for an increasingly energy hungry world. Wind, solar and biomass have moved into the public arena only in the last few years.

The proposed patented device (US Patent No.: 7,468,563) Ocean Wave Energy Converter harnesses the energy of ocean waves by continually raising and …

Research On Electrochemical Performance Of Lithium-Ion Battery Cathode Material Lini(1/3)Co(1/3)Mn(1/3)O2 In Aqueous Lino3 Solution, Jun Zheng, Xin Jia, Chong Wang, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The cathode material of LiNi_1/3Co_1/3Mn_1/3O₂ synthesized by sol-gel method shows excellent high rate performance, and high output power density during discharge process. A well-ordered layered α-NaFeO₂ structure was confirmed by XRD and a primary particle size of about 500 nm was indicated by SEM. Galvanostatic charge-discharge test indicates that LiNi_1/3Co_1/3Mn_1/3O₂ in 2 mol·L^-1 LiNO₃ aqueous solution with pH 12 reached a ca-pacity of 147 mAh/g while charged and discharged at 2C. The capacities were 64, 33, 16 mAh/g with 80C (14.4 A/g), 150C …

Fabrication Of Electrochemically Activated Glassy Carbon/Bismuth Film Electrodes For Sensitive Analysis Of Pb(2+) And Cd(2+), Kang Shi, Wen-Jing Wang, Kun Hu

Journal of Electrochemistry

The application of electrochemically activated glassy carbon (GC) in the in-situ preparing of bismuth film electrodes (BiFEs) to analyze Pb^{2 +} and Cd^{2 +} was investigated. The glassy carbon electrodes were electrochemically activated by either potentiostic or cyclic polarization in 1 mol·L^-1 NaOH solution. Experimental results show that employment of HCl solution as the analytical solution not only can reproducibly renew the electrochemically activated GC electrode surface with an electrochemical clear procedure, but also can greatly enhance the sensitivity of BiFes method for analysis of Pb^{2 +} and Cd^{2 +}. The test range thus …

Failure Reaction Mechanism Of Internal Short-Circuit For Lithium-Ion Batteries, He Li, Shen-Jun Yu, Zhi-Kui Chen, Guang-Chuan Liang

Journal of Electrochemistry

In this work, the battery impact testing machine has been used to study the failure progress of internal short-circuit (ISC) for lithium ion batteries. The reaction mechanisms between cathode/anode and electrolyte in the battery at different temperatures were characterized by differential scanning calorimetry (DSC), gas chromatography/mass spectrometry (GC/MS) and X-ray diffraction (XRD). The experimental results show that the ISC failure of the battery was mainly due to the reaction between cathode Li_0.5CoO₂ and electrolyte. The decomposition and oxygen evolution reactions of cathode occurred when the temperature reached a certain value. At the same time a fierce oxidation …

Synthesis And Electrochemical Properties Of Li3V2(Po4)3/C Cathode Materials For Lithium Ion Battery, Li-Ying Liu, Hai-Yan Zhang, Lian Chen, Yu-Chun Zhai

Journal of Electrochemistry

Cathode material Li₃V₂(PO₄) ₃ /C for Lithium-ion battery was synthesized by combination of ball milling and baking. Physical and electrochemical performances of as-prepared materials were characterized through XRD,EIS and galvanostatic cell cycling. The results show that the products were monoclinic Li₃ V₂ (PO₄) ₃ with well-developed crystal structure. At 0. 1C,0. 25C and 0. 5C,the initial discharge capacities were 150. 6,134. 1 and 107. 1 mAh·g^-1 ,respectively. Capacity retention rates were 87. 3% after 130 cycles at 0. 25C and 87. 2% after 105 cycles at 0. 5C. Charge-discharge …

Optimization Of Membrane Electrode Assembly In Air-Breathing Direct Methanol Fuel Cell, Liang Ma, Wei-Wei Cai, Jing Zhang, Liang Liang, Jian-Hui Liao, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The structure and performance of MEA were optimized by tailoring the catalyst layer,cathodic microporous layer (MPL) ,anodic MPL and membrane,with the considerations of unique characteristics of airbreathing direct methanol fuel cell (DMFC) such as methanol crossover and cathode flooding. It was found that high catalyst loading could suppress the methanol crossover effectively,but too high catalyst loading can lead to high mass transport resistance. Hydrophobic anodic MPL with 30% (by mass) PTFE could facilitate the CO₂ bubble detachment,which decreased the methanol concentration gradient and suppressed the methanol crossover accordingly. When Nafion 115 was used as membrane,methanol crossover was severe,while Nafion …

A High Performance Sulfur/Carbon Xerogel Composite In Lithium Sulfur Battery Application, Chong Wang, Jia-Jia Chen, Qiu-Jie She, Qian Zhang, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Sulfur/carbon composite was synthesized by the thermal method with the carbon xerogel as the conductive framework. The property of composite was characterd by XRD and SEM. It shown that the composite with the particle size below 10 μm had the same morphology as the carbon xerogel and the sulfur was absorbed in the pores in non-crystalline. The discharge capacity of the composites were 1311 mAh/g and 1107. 1 mAh/g at 0. 1C and 0. 2 C rates,respetively. And a retention capacity was about 800 mAh/g after 30 cylcyes.

Nano/Micro-Structured Electrode Materials For Lithium-Ion Batteries, Yu-Guo Guo, Zhong-Li Wang, Xing-Long Wu, Wei-Ming Zhang, Li-Jun Wan

Journal of Electrochemistry

Nanostructured materials are currently of interest as high performance anodes and cathodes for rechargeable lithium-ion batteries because of their novel nano-size effects and significantly enhanced kinetics. This review paper describes some recent developments in this field,addressing the size effects,morphology effects,as well as the functions of carbon coating layers toward lithium storage. Several"kinetically stabilized"nano/microstructured electrode materials and high-rate electrode materials with mixed-conducting networks based on the work of the authors are highlighted for illustration.

Electrocatalytic Oxidation Of Hcooh At Au(Core)-Pd(Shell)-Pt(Cluster) Nanocubes, Qing-Ning Jiang, Huan Li, Ning Yang, Ping-Ping Fang, Feng-Ru Fan, Zhong-Qun Tian

Journal of Electrochemistry

Gold nanocubes were synthesized by a two-step seed-mediated growth method. The Aucore-Pdshell and Au_core-Pd_shell-Pt_cluster nanocubes with controllable shell thickness of Pd and cluster coverage of Pt were synthesized by simply changing the amount ratio of H₂PdCl₄ or H₂PtCl₆. The samples were characterized by scanning electron microscope (SEM) , transmission electron microscopc (TEM) and cyclic voltammetry (CV). CV was then used to make a systematic study on the dependence of the electrocatalytic properties on the shell thickness of Au_core-Pd_shell and Pt coverage of Au_core-Pd …

High-Rate Cyclic Properties Of Hollow Carbon Hemisphere As Anode Materials For Lithium Ion Batteries, Guang-Hui Zhang, Zao-Xue Yan, Hong-Li Zou, Pei-Kang Shen

Journal of Electrochemistry

High surface area hollow carbon hemispheres (HCHs) covered with hard carbon layers have been synthesized by using polystyrene spheres (PSs) as templates under hydrothermal method combined with the intermittent microwave heating (IMH) method. The morphologies of the materials are characterized by SEM and TEM. The electrochemical properties of the HCHs are tested. Comparing with graphite and mesocarbon microbeads (MCMB) ,the HCHs show higher capacity and excellent cyclic life performance.

Synthesis Of Cosalen Composite In Apo-5 And Its Electrocatalytic Behaviour For Reaction Of Dioxygen Reduction, Rong Zhang, Li-Hua Tang, Bin-Bin Fan, Jing-Hong Ma, Rui-Feng Li

Journal of Electrochemistry

CoAPO-5 molecular sieve was hydrothermally synthesized. The Cobalt ions in CoAPO-5 were coordinated with the SALEN ligend diffusing into the channels of the molecular sieve to form CoSALEN complexes. The electrochemical behaviors and electrocatalysis for dioxygen reduction of the CoSALEN complex immobilized in APO-5 modified glassy carbon electrodes (GCEs) have been investigated by cyclic voltammetry (CV) and chronoamperometry (CA) in differrent pH aqueous solutions. The results showed that the PS/CoSALEN/APO-5 /GC modified electrode is of the high electrocatalytic activity towards dioxygen reduction in pH 6. 86 buffer solution with a reduced overpotential of 447 mV lower than bare GC electrode. …

Influence Of Ions Dimension On The Electric Field Activation Of Micro-Crystallite Carbon, Gang-Wei Sun, Wen-Hua Song, Guo Cheng, Wen-Ming Qiao, Li-Cheng Ling

Journal of Electrochemistry

Micro-crystallite carbon (CC) was synthesized by KOH activation of carbonized petroleum coke precursors. The porous properties structure and crystallite structure were characterized by N₂ adsorption-desorption, X-ray diffraction (XRD) measurements. The capacitive behavior of CC was investigated in the electrolyte of Et₄NBF₄/PC, Et₄NBF₄/AN, Bu₄NBF₄/PC and Bu₄NBF₄/AN, respectively. Results showed that the lower potential of electric field activation (EFA) was obtained in the solvent of AN than in PC, which was ascribed to the fact that smaller solvated ions dimension in AN facilitating the intercalation …