Power and Energy Commons^™

Heating Effects Through Harmonic Distortion On Electric Cables In The Built Environment, Kevin O'Connell

Doctoral

Under ideal circumstances, electric power supply voltage and current waveforms should be sinusoidal. However, this is very seldom the case in the built environment, due to the proliferation of non-linear loads. Examples of non-linear loads are those containing switched mode power supplies, reactors and electronic rectifiers/inverters. Common devices such as personal computers, fluorescent lighting, electric motors, variable speed drives, transformers and reactors and virtually all other electronic equipment are examples of non-linear loads. Non-linear loads are the norm in the built environment rather than the exception. Such loads produce complex current and voltage waves and simple spectral analysis of these …

Simulation Of Power Control Of A Wind Turbine Permanent Magnet Synchronous Generator System, Nantao Huang

Master's Theses (2009 -)

This thesis presents a control system for a 2MW direct-drive permanent magnet synchronous generator wind turbine system with the objectives to capture the optimal power from the wind and ensure a maximum efficiency for this system. Moreover, in order to eliminate the electrical speed sensor mounted on the rotor shaft of the PMSG to reduce the system hardware complexity and improve the reliability of the system, a sliding mode observer based PM rotor position and speed sensorless control algorithm is presented here.

The mathematical models for the wind turbine and the permanent magnet synchronous machine are first given in this …

Optimization Of Solar Cell Arrays Using The Fibonacci Search Algorithm, Felicia Tyyan Farrow

Electrical & Computer Engineering Theses & Dissertations

In our energy hungry world, there is a growing demand to develop creative mechanisms to extract, conserve, and use energy from different resources. The use of solar cells to extract and convert solar energy into electrical energy is a growing and popular field of study because solar energy is clean, free, and renewable. One limitation for photovoltaic (PU) or solar technology is its loss in efficiency and availability as a result of shading or partial shading. Shading or partial shading decreases the total capable output power that the PV system can produce because the array is receiving irradiation from the …

Effect Of Ethyl Propionate On Low-Temperature Performance Of Lifepo4-Based Li-Ion Battery, Xiao-Ping Li, Lian-Sheng Hao, Wei-Shan Li, Meng-Qing Xu, Li-Dan Xing

Journal of Electrochemistry

A linear carboxylic, ester ethyl propionate (EP), was used as the co-solvent of carbonates, ethylene carbonate (EC), ethyl-methyl carbonate (EMC) and dimethyl carbonate (DMC), and its effect on low-temperature performance of LiFePO₄-based Li-ion battery was studied by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge test. The application of EP enhances the ionic conductivity of the electrolyte, improves the compatibility of the electrolyte with both LiFePO₄ and graphite materials, and thus improves the low-temperature performance of LiFePO₄-based Li-ion battery. The Li-ion battery using the optimized electrolyte of 1 mol·L^-1 LiPF₆/EC:EMC:DMC:EP …

Multifunctional Corrosion Inhibition Behavior Of Zn-Al Calcined Layered Double Hydroxides For Steel Rebar In Nacl Solution, Xiao-Juan Zhang, Jing-Jing Wang, Shi-Gang Dong, Chang-Jian Lin

Journal of Electrochemistry

The Zn-Al layered double hydroxides (Zn-Al LDHs) and calcined products (Zn-Al CLDHs) were synthesized successfully under a routine air atmosphere. The results showed that both Zn-Al LDHs and Zn-Al CLDHs had obvious flake structures. The corrosion inhibition of Zn-Al CLDHs for steel rebar in NaCl solution was studied by electrochemical techniques. It was found that the corrosion rate of steel rebar decreased significantly after the steel rebar was treated by Zn-Al CLDHs in NaCl solution for 3 h. It was indicated that Zn-Al CLDHs could absorb Cl^- and release OH^- during their reconstruction process, which provided dual protection …

Influences Of The Cinnamic Acid On Zinc Electrodeposition At Glassy-Carbon Electrode, Kai Li, Shen Chen, Shen-Na Liu, Bi-Sang Chen, Heng Lin, Guo-Liang Chen, Qing-Xiang Wang

Journal of Electrochemistry

The influences of cinnamic acid (CIN) on the mechanism of Zn deposition and nucleation kinetics onto glassy-carbon electrode were studied by cyclic voltammetry (CV) and chronoamperometry (CA). The results revealed that the zinc reduction took place via Zn²⁺ + 2e → Zn in the presence of CIN, but the kinetics of zinc deposition was changed and the formation rate of zinc nuclei was accelerated. In the absence of CIN, the mechanism of zinc nucleation followed the 3D-instantaneous diffusion-controlled nucleation, while the 3D-progressive diffusion-controlled nucleation in the presence of CIN. The addition of CIN reduced the nucleation rate, but increased …

Preparation And Characterization Of A Novel Composite Electrolyte Ceria-Sulfate For Intermediate Temperature Solid Oxide Fuel Cells, Ze Tong, Yi-Mei Yin, Jie-Wei Yin, Zi-Feng Ma

Journal of Electrochemistry

A novel composite electrolyte SDC-(Li/Na)₂SO₄ was prepared for intermediate temperature solid oxide fuel cells (ITSOFC). The phase structure and cross-sectional morphology were examined by XRD and SEM, respectively, and the ionic conductivity was investigated by AC impedance in a temperature range of 400 ^oC ~ 700 ^oC in air. It was found that the composite electrolyte was composed of two phases: crystal SDC and amorphous (Li/Na)₂SO₄. The conductivity of the composite electrolyte was significantly larger than that of SDC at intermediate temperatures (550 ^oC ~ 700 ^oC) and increased …

Preparation And Electrochemical Performance Of Hollow Carbon Spheres/Sulfur Composite, Jun Zang, Hang Qian, Er-Man Zeng, Juan-Ni Fu, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Hollow carbon spheres were prepared by the PMMA template. Hollow carbon spheres/sulfur composite was made from sulfur and hollow carbon spheres as a conducting framework. The results of SEM and TEM showed that sulfur was uniformly filled in both of the shell and hollow core of hollow carbon spheres. The electrochemical performance of hollow carbon spheres/sulfur composite was characterized by the charge/discharge method. The results showed the excellent rate and cycle performance of hollow carbon spheres/sulfur composite. The reversible capacities of hollow carbon spheres/sulfur composite are 1145 mAh·g^-1, 824 mAh·g^-1, 702 mAh·g^-1, 586 mAh·g …

Polypyrrole-Transition Metal-Oxygen Coordination Complexes As High Performance Lithium Storage Material, Ya Mao, Qingyu Kong, Bingkun Guo, Zhaoxiang Wang, Liquan Chen

Journal of Electrochemistry

No abstract provided.

Influence Of Electrode Hydrophobicity On Performance Of Alkaline Polymer Electrolyte Fuel Cells, Li-Sheng Tan, Jing Pan, Yao Li, Lin Zhuang, Jun-Tao Lu

Journal of Electrochemistry

In the present work, we study the influence of the electrode hydrophobicity on the performance of alkaline polymer electrolyte fuel cells (APEFCs). QAPS or xQAPS is employed as the membrane and the ionomer, while PTFE is used as a hydrophobic additive in order to adjust the electrode hydrophobicity. We find that enhancing the hydrophobicity of anode can promote the performance of APEFCs, while a moderate hydrophobicity of cathode is required to achieve optimal performance. By using xQAPS as the electrolyte and adding some PTFE in the anode, a peak power density of 132 mW·cm^-2 can be obtained at a …

Progress Of Lithium Rich Cathode Materials For Li-Ion Batteries, Jie Zhang, Jiu-Lin Wang, Jun Yang

Journal of Electrochemistry

Lithium rich materials xLi₂MnO₃·(1-x)LiMO₂ (0-1 and low cost. However, the large irreversible capacity during the first cycle, low rate capability and structure collapse during cycling remain impediments in developing these cathodes for applications. The structure analyses and charge/discharge mechanisms for lithium rich materials are currently main research contents. Although whether the lithium rich materials are solid solutions or composite is still controversial, oxygen release mechanism on the first charge 4.5 V plateau of lithium rich materials has come to consistency. Several modifications, such as bulk doping, surface coating and microstructure control, demonstrate promising strategies to …

Electrochemical Performance Of Al-Doped Spinel Limn2O4 Cathode Material For Li-Ion Batteries, Yong-Long Wang, Wen-Ge Wang, Qian Zhang, Xin Wang, Jian-Sheng Cao, Shi-Hai Ye

Journal of Electrochemistry

Spinel LiMn₂O₄, a cathode material for Li-ion batteries, is featured as good high-rate performance, low cost and environmental friendly. The pristine and Al-doped LiMn₂O₄ samples were prepared by sol-gel method. The structure and micromorphology of the as-prepared samples were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results demonstrated that the as-prepared LiMn₂O₄ samples had a typical cubic spinel structure and were composed of sphere-like particles with a diameter range of 300 ~ 500 nm. Galvanostatic charge-discharge tests showed that the LiMn₂O₄ samples doped …

Electrocatalytic Mechanism And Porous Electrode Mass Transfer Process In Membrane Electrode Assembly For Direct Methanol Fuel Cells, Xin-Dong Wang, Yi-Tuo Wang, Gui-Cheng Liu, Meng Wang, Zhe Tian

Journal of Electrochemistry

Direct methanol fuel cell (DMFC) is considered to be a promising commercial energy conversion device for portable electronics due to its many advantages. In order to improve the performance of DMFC, many companies and research institutes have been launching the deep research and obtaining a lot of conspicuous achievements. In this paper, the electrocatalytic mechanism and porous electrode mass transfer process in membrane electrode assembly (MEA) are analyzed. In addition, combined with the preparation process of MEA, multilayer ordered structures and internal transfer process of the cell, recent progresses of MEA in DMFC are discussed.

Fabrication And Performance Of Lani0.6Fe0.4O3-δCathode Modified By Coating With Gd0.2Ce0.8O2 For Intermediate Temperature Solid Oxide Fuel Cell, Rui-Xuan Ren, Bo Huang, Xin-Jian Zhu, Yi-Xing Hu, Xiao-Yi Ding, Zong-Yao Liu, Ye-Bin Liu

Journal of Electrochemistry

The symmetric cell of LaNi_0.6Fe_0.4O_3-δ/Sc_0.1Zr_0.9O_1.95/LaNi_0.6Fe_0.4O _3-δ was fabricated with screen printing method. A LaNi_0.6Fe_0.4O_3-δ (LNF) cathode was modified by coating with nano-sized gadolinium-doped ceria (GDC, Gd_0.2Ce_0.8O₂) prepared using a simple combustion process within the pores of the cathode. According to the electrochemical impedance spectra (EIS), the polarization resistance of the pure LNF was 0.70 W·cm² at 750 ºC, while 0.13 W·cm² for the 21.3% GDC (by mass)-coated LNF cathode at the …

Influence Of Media Composition On The Growth Rate Of Chlorella Vulgaris And Scenedesmus Acutus Utilized For Co2 Mitigation, Czarena L. Crofcheck, Xinyi E, Aubrey Shea, Michael D. Montross, Mark Crocker, Rodney Andrews

Biosystems and Agricultural Engineering Faculty Publications

Atmospheric carbon dioxide levels have increased since the industrial revolution due to increasing combustion of fossil fuels. One possible CO₂ mitigation strategy is the use of microalgae for mitigation of CO₂. This paper focuses on the influence of media composition on the growth rate of two microalgae strains, Chlorella vulgaris and Scenedesmus actus. A KNO₃ based medium was found to work better for Chlorella, while a urea based equivalent worked better for Scenedesmus. The urea based media investigated here resulted in growth similar to that found with previously reported KNO₃ based media. …

Cal Poly Wind Power Research Center Power Regulator, Ricardo Rodriguez, Steven Bounchareune

Electrical Engineering

Through funding from the California Central Coast Research Partnership (C3RP) the

CPWRC, led by Dr. Patrick Lemieux, has erected a horizontal axis wind turbine (HAWT) at the

Cal Poly Escuela Ranch site EL04. With the help of Dr. John Ridgely and Dr. Art MacCarley, the team has implemented a controller that delivers the power being generated by the turbine to a resistor bank which maintains a safe working speed for the turbine. The authors objectives for this project are to (1) become familiar with the operation of the turbine, (2) develop an AC-DC converter that regulates the output of the …

Rapid Tool Heating, Jason Chi, Bobby Dodge

Mechanical Engineering

Quatro Composites creates various molded parts for an array of industries. They are seeking to improve their thermoplastic molding process by decreasing the amount of time to heat up the steel tool that molds the thermoplastics. Currently, it takes approximately 1 hour to heat up their 120 pound steel mold from room temperature to approximately 700°F. The goal of this project is to create an optimum heating method that will minimize that heating time to about 20 minutes or less. It is critical for the stakeholders (Quatro Composites) to have a faster heating time in order to increase their production …

Design Of An Energy Efficient Virtual End Node Client Using Openadr2.0a And Smap, Kevin Navero

BioResource and Agricultural Engineering

Demand Response (DR) describes the set of actions taken to impose a reduction in electrical loads to stabilize the power grid and decrease costs. It is used when power grid emergencies or extremely high demand and congestion, threaten the electricity supply-demand balance. Automated Demand Response (ADR) describes a web-based control system that triggers DR events automatically by signaling other pre-programmed control systems. This project intends to use the OpenADR2.0 specifications provided by the OpenADR Alliance to construct an open source Virtual End Node (VEN) client to retrieve DR signals. The Simple Measurement and Actuation Profile (sMAP) software is also used …

Unipolar Pulse Width Modulation Inverter, Randy Baggao, Gabriel Tam

Electrical Engineering

This project portrays the design and construction of a pulse width modulation (PWM) inverter. The inverter is implemented as a unipolar converter. The inverter provides a steady single-phase sinusoidal 60Hz AC voltage output from a DC input. This is a basic DC-AC power converter that is built in 3 separate phases and integrated altogether at the end. The inverter can be broken down into the control unit, firing circuit, and the H-bridge. By using the PWM method, one can control the frequency and amplitude of the output by using a reference signal. This method will also avoid using a transformer …

Low Speed Alternator Design, Scott Merrick

Electrical Engineering

No abstract provided.

Micro Hydropower System, Christpher Neally, Ian Verstuyft

Electrical Engineering

The micro hydropower project strives to meet the needs of a specific village in northern Thailand in partnership with Engineers Without Borders. Specifically, the electrical side of the system must be designed to convert the mechanical power of a flowing river that is turning a turbine into sustainable and dependable power. Currently available hydropower systems will be considered, analyzed, and tailored to suit the specific needs of the community in need. The system to be designed will be flexible enough to demonstrate proof-of-concept with the limited maximum generable power in lab while having the ability to be easily scaled for …

Multiple Input Single Output (Miso) Tablet/ Phone Charger, Kevin Wong

Master's Theses

This thesis entails the design and implementation of a multiple input single output (MISO) DC-DC converter using the flyback topology to charge tablets/ smartphones or any USB powered portable device. The MISO converter will enable the use of various renewable energy sources such as a solar panel/ rechargeable battery combination, bicycle dynamo, hydroelectric power, and wind turbine. This paper will cover the design, simulations, and test results of the MISO converter. The flyback topology was chosen due to its low part count and its efficiency at low power. The proposed converter has a nominal 12V input to output USB 2.0 …

Ocean Wave Generator Using Electromagnetic Induction, Sutton Smiley, Adam Mccuistion

Electrical Engineering

No abstract provided.

Off Grid Solar Powered Street Light, Justin Fang, Billy Pham

Electrical Engineering

Street lights are fixtures found in every city and serve the important purpose of illuminating the streets and keeping the roads safe for pedestrians and drivers. Current street lights are powered by the grid, power which is paid for by the taxpayers and could have been used to power homes instead. With this project, our goal is to design and implement an electric power system that collects and stores solar energy, and delivers power to an LED smart street light. The resulting system would reduce street light energy costs by 100% since they would not draw any power from the …

Energy Dashboard Tool For Cal Poly Dormitories, Katie Zombro

Electrical Engineering

This project defines the needs, uses, and future projects (as well as business cases and procurement) of a University Housing dashboard tool, utilized by the Red Brick Dormitories on the Cal Poly campus. This easily accessed tool provides simple information regarding energy trending data, allowing for all student residents no matter their academic discipline, to understand their energy trends and opportunities for reduction. With the Energy Dashboard in place, Cal Poly’s red brick dormitories experienced savings ranging from 10%-20% from the 2011-2012 school year baseline, by the end of the 2012-2013 academic year. With the help of the Dashboard, competitions …

Differential Transformer Protection Using The Sel 387 And Sel 587 Microprocessor Relays, Ryan Chun

Electrical Engineering

The objective of this Senior Project is to use the SEL 387 current differential and overcurrent microprocessor relays to protect three-single-phase 1 KVA 120:208 transformers configured in ∆-∆, Y-Y, Y-∆, and ∆-Y connections. In the second phase of this project, is to create a functioning lab that uses the SEL 587 relay to teach basic differential transformer protection for the upcoming EE-444 students.

The protection schemes developed in both of the senior project phases require the use of differential and overcurrent protection elements by monitoring the changes of the input and output current through the transformer. When these currents fail …

Design Of Improved Distribution Panel For The Dc House, Nolan Joksch

Electrical Engineering

The DC House is a humanitarian project intended to provide electricity to rural areas that would benefit from electricity, but are too remote to have access to it. This particular project is to design and construct the feeder box for the electrical distribution system to distribute power to the system as well as protect it. Building an electrical panel that is easily maintained and, above all, safe for the user is key to this project.

Merry-Go-Round Human Powered Generator, Daniel Barnicle, Dario Romero

Electrical Engineering

This project entails the design and construction of a Merry-Go-Round Human Powered Generator for the DC House project. The Merry-Go-Round Human-Powered-Generator is a sustainable project focusing on utilizing renewable human mechanical energy. As young children play on the Merry-Go-Round, the generator converts the mechanical energy to electrical energy for the DC House. The Merry-Go-Round Generator boosts the generated voltage output to power a battery. This electrical energy then transfers from the battery to the DC House to provide power to it.

Alternative Wheelchair Control System, Jessica Hendricks, Tara Keigharn

Electrical Engineering

We geared this project towards assisting an individual with limited[1] motor function to operate a wheelchair. The product targets individuals who find use of a joystick is ineffective or painful. We focused our design on the wheelchair bought from Adaptive Driving Systems (Driving, 2013); but ultimately we would like to field a final product capable of applying to any electric wheelchair. Our goal: a person to operate the electric wheelchair using sensors that transmit a translation of an individual’s hand movement through a wireless transmission to a microcontroller installed on the wheel chair that then controls the wheelchair’s movement. …

Wind And Hydroelectric Power Simulation For The Dc House Project, Randy Lormand, Christopher Goloskie

Electrical Engineering

This project details the design and integration of a wind and hydroelectric power simulation system in correlation with the DC House Project. The simulator uses variable speed drives to rotate a DC motor which then drives a generator to produce output. This output is then regulated using a DC to DC converter which holds the voltage level constant making it easier to interface with other power sources for the house. The test results indicate that the simulator will be able to produce two separate power outputs that will provide at least 70 Watts of power in the acceptable speed range …