Power and Energy Commons^™

Merry-Go-Round Human Powered Generator, Sarah Lorraine Ashe, Salvador Navarro

Electrical Engineering

How do you bring electricity to families who have limited resources in a developing country? The DC House project, advised by Dr. Taufik, provides a way for kids to have fun, exercise and generate power for their homes – play-park human powered generators. This project intends to create a more efficient and cost effective way for playground equipment to be implemented for power generation. The redesigned and reconstructed merry-go-round human powered generator converts mechanical energy into electrical energy to power the DC house. This was a fully functioning generator that needed a better voltage gain, as well as, a more …

Human-Powered Swing Generator, Danny Cai, Timothy Lai, Brandon Wong

Electrical Engineering

Many developing countries lack sufficient resources to provide enough electricity for every family to live with a satisfying level of comfort and convenience. Our project proposes a solution that provides families with an alternative access to electricity using a playground swing. This project addresses the design and construction of the Human-Powered Swing Generator, which converts mechanical energy to electrical energy for charging a battery. The charged battery serves as a source of DC energy for potential DC purposes, such as charging a cell phone.

Integration Of Pv & Simulated Dc Sources For The Dc House, Arvind Ramesh, Kevin Gingrich, Scott Chau

Electrical Engineering

The DC House, an ever improving project, uses only pure DC power which most renewable energy sources generate, from solar to wind power. The DC House and this project expect a donation of photovoltaic modules to supply a constant source of DC power. At the moment, the DC House desperately needs power sources because not only does the house have various loads unaccounted for, but the distribution system to determine proper power flow needs a redesign. The project chose to account for these issues by implementing a solar panel onto the DC House and a power distribution module to have …

Dual High-Voltage Power Supply For Use On Board A Cubesat, Nicholas Weiser

Master's Theses

Since their conception in 1999, CubeSats have come and gone a long way. The first few that went into space were more of a “proof of concept,” and were more focused on sending simple data and photographs back to Earth. Since then, vast improvements have been made by over 40 universities and private firms, and now CubeSats are beginning to look towards interplanetary travel. These small satellites could provide a cost effective means of exploring the galaxy, using off the shelf components and piggy-backing on other launch vehicles with more expensive payloads. However, CubeSats are traditionally launched into Low Earth …

Improvements To A Bi-Directional Flyback Dc-Dc Converter For Battery System Of The Dc House Project, Michael Wu

Master's Theses

The DC House project relies primarily on renewable energy sources to provide DC power to the various loads of the house. However, not all renewable sources are capable of providing power at all times of the day. A back-up energy source in the form of a battery storage system must be available to meet the electrical needs of the house. A bi-directional flyback power converter was initially designed to allow a battery to charge from as well as discharge to the 48V bus line of the DC House. The design provided a 35W prototype to demonstrate the converter’s feasibility. Further …

Is Biofuel A Feasible Long-Term Chief Energy Source? A Global Perspective, Rajee Olaganathan, Aston Lee, Debra Tong, Mameegate Zheng Jun Cheston, Zack Ho Xuan Yi

Publications

This scientific paper examines the feasibility of officiating biofuels as the future chief energy source of the world. It weighs the pros and cons of the four different generations of biofuels that have been discovered over time, explaining how the raw materials used in each generation determines each individual level of long-term sustainability. It then further analyses both general advantages and disadvantages, comprising of economic, social, health and environmental impacts; giving the reader an unbiased perspective. Few case studies have also been reviewed to better understand the implications of drawing energy from biofuels, as well as the current state of …

Design And Prototyping Of An Antenna-Coupled Cryotron, Shauna Jensen

Dissertations and Theses

Grid-scale integration of renewable energy sources and smart grid devices has created new demands in flexible power conversion. State-of-the-art semiconductor power switches present limitations in power handling capability, as well as forward and reverse breakdown voltages. Superconducting materials are a viable alternative due to their robustness against high ampacities, large electric fields and abrupt changes in power flow. This work pays focus to material testing and apparatus design for an antenna-coupled cryotron (ACC), which is a superconducting power switch.
Design, fabrication and testing are examined for a longitudinal resonant cavity, paired with monopole transmit and modified slot receive antennae. These …

Defect Levels In Cu₂Znsn(Sₓse₁₋ₓ)₄ Solar Cells Probed By Current-Mode Deep Level Transient Spectroscopy, S. Das, S. K. Chaudhuri, R. N. Bhattacharya, K. C. Mandal

Faculty Publications

No abstract provided.

Evaluation Of Methods For Control Of Vegetation In Utility Corridors, George V. Rancea

Master's Projects and Capstones

Vegetation management programs are now one of the largest budget items for most of the utility companies in the United States. Control methods used in line clearance activities include mechanical trimming, planting management, or use of tree growth regulators (chemicals that suppress the production of gibberellins, the plant hormones that control stem elongation). Choosing the appropriate control method is a decision that vegetation program managers should take based on many factors, like costs, environmental impacts, existing agreements with the landowners, terrain, public perception etc. To find a balance between competing interests – a reliable and economic electric system on one …

Dynamic Rating Of Transmission Lines For Improved Wind Energy Integration In Complex Terrain, Tyler Bennett Phillips

Boise State University Theses and Dissertations

Transmission congestion is a growing concern that could limit integration on new renewable energy projects to the electricity grid. Because construction of new transmission lines is a long and expensive process, transmission service providers are investigating dynamic line rating (DLR) mehtods that could potentially increase capacity of existing transmission lines. DLR is a smart-grid technology that enables rating of power lines based on real-time conductor temperature that is dependent on local weather conditions. whereas conventional practice relies on a static rating, which is based on conservative local weather assumptions to limit transmission line sag.

With todays improved wind and weather …

Design Of A High Temperature Subsurface Thermal Energy Storage System, Qi Zheng

All Theses

Solar thermal energy is taking up increasing proportions of future power generation worldwide. Thermal energy storage technology is a key method for compensating for the inherent intermittency of solar resources and solving the time mismatch between solar energy supply and electricity demand. However, there is currently no cost-effective high-capacity compact storage technology available (Bakker et al., 2008). The goal of this work is to propose a high temperature subsurface thermal energy storage (HSTES) technology and demonstrate its potential energy storage capability by developing a solar-HSTES-electricity generation system. In this work, main elements of the proposed system and their related state-of-art …

Broadband Nanostructured Antireflection Coating For Enhancing Inas/Gaas Quantum Dots Solar Cells Performance, Jony C. Sarker

Graduate Theses and Dissertations

The broadband suppression in reflection is one of the primary focuses in high efficiency solar cell research. In this thesis, a moth-eye inspired nanostructure antireflection coating is fabricated on InAs/GaAs quantum dots solar cell in order to enhance the power conversion efficiency. The abrupt refractive index transition between air and GaAs surface is replaced by a tapering zinc oxide nanoneedle on planar tantalum pentoxide coating. The antireflection structure provides gradual reduction of refractive index away from the solar cell top surface.

The nanostructured antireflection coating is fabricated by utilizing chemical bath deposition of tapered zinc oxide nanoneedles on planar tantalum …

Modeling And Simulation Of Parallel D-Statcoms With Full-Wave Rectifiers, Jason Brinsfield

Master's Theses

In recent years, both a significant increase in electrical demand and a large influx of intermittent renewable energy sources have put a considerable stress on the nation’s electrical grid. Conventional power flow control techniques such as capacitor banks and tap-changing transformers are incapable of adequately handling the rapid fluctuations in power supply and demand that today’s grid experiences. Flexible AC Transmission System (FACTS) controllers are a practical way to compensate for such rapid power fluctuations. One type of shunt FACTS controller is the Static Synchronous Compensator (STATCOM), which uses fully controllable switches to source or sink reactive power to a …

Evaluation Of Conservation Voltage Reduction As A Tool For Demand Side Management, Ali Dorrody

UNLV Theses, Dissertations, Professional Papers, and Capstones

To ensure stability of the power grid, electricity supply and demand must remain in balance in real time. Traditionally utilities, call upon peaking power plants to increase power generation to meet the peak demand during the afternoons of the hot summer months. Demand-side management (DSM), which includes energy efficiency and demand response (DR), works from the other side of the equation - instead of adding more generation to the system, it pays energy users to reduce consumption as it is cheaper and easier to procure than traditional generation. As a consequence, demand-side management allows utility customers to act as a …

Anisotropy Of The Reynolds Stress Tensor In The Wakes Of Counter-Rotating Wind Turbine Arrays, Nicholas Michael Hamilton

Dissertations and Theses

A wind turbine array was constructed in the wind tunnel at Portland State University in a standard Cartesian arrangement. Configurations of the turbine array were tested with rotor blades set to rotate in either a clockwise or counter-clockwise sense. Measurements of velocity were made with stereo particle-image velocimetry. Mean statistics of velocities and Reynolds stresses clearly show the effect of direction of rotation of rotor blades for both entrance and exit row turbines. Rotational sense of the turbine blades is visible in the mean spanwise velocity W and the Reynolds shear stress -[macron over vw]. The normalized anisotropy tensor was …

Preparation And Electrochemical Performances Of Cofe2O4/Gns Nanocomposites As Anode Material For Lithium Ion Battery, Mo-Chao Cai, Sen-Rong Cai, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

The CoFe₂O₄/GNS was synthesized by a simple one-pot solvothermal method. The results obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM) showed that the CoFe₂O₄ particles with sizes of 15 nm dispersed on the surface of graphene uniformly. Electrochemical tests indicated that the CoFe₂O₄/GNS nanocomposite exhibited excellent cyclic stability with almost 95.8% capacity retention after 100 cycles at the current density of 500 mA·g^-1 and delivered a high reversible capacity of 482 mAh·g^-1 at the current density of 2 A·g^-1.

Effect Of Temperature On The Self-Humidifying Open-Cathode Proton Exchange Membrane Fuel Cell, Si-Chen Zhao, Ben Wang, Qiu-Hong Jia, Ming Han, Yu-Hong Xie

Journal of Electrochemistry

Based on the experiments about the output characteristics of a home-made temperature-controlled PEMFC system with atmospheric pressure and no external humidifying condition in different loading voltages and operating temperatures, the optimum operating temperature at different loading voltages can be obtained by tracking the output characteristics of PEMFC operating over a range of temperatures. By analyzing the fitted data the kinetic parameters are evaluated and the effect of different operating temperatures on the PEMFC performance is discussed from a view of electrode kinetics.

Preparation Of Pt/H-Tio2 Catalyst With Improved Catalytic Performance For Methanol Electrooxidation, Jin Han, Zhi-You Zhou, Qiang Wang, Miao-Qiang Lv, Chi Chen, Shi-Gang Sun

Journal of Electrochemistry

White TiO₂ nanorods were synthesized by hydrothermal method with TiCl₄ as a precursor. As-synthesized TiO₂ nanorods were further subjected to high-temperature (550 ^oC) heat treatment for 2 h under H₂ atmosphere to prepare gray black hydrogen-treated TiO₂ (H-TiO₂) nanorods with oxygen vacancies and Ti³⁺ interstitial atoms. The Pt nanoparticles of 1.9 nm were supported on these two types of TiO₂ nanorods to form Pt/TiO₂ and Pt/H-TiO₂ catalysts. XRD data indicates that the crystal structure of TiO₂ was still reserved as rutile after hydrogen treatment, but the surface …

An Equivalent Circuit Model For Redox Flow Battery Stack, Dong-Jiang You, Hua-Min Zhang

Journal of Electrochemistry

This paper introduces an equivalent circuit model for a redox flow battery stack. The model combines the electrochemical reaction of the battery cell and the shunt current of the battery stack. An all-vanadium redox flow battery stack of 1kW rated output power is tested through transient response and self-discharge experiments. All the parameters used for the modeling are obtained. Calculated shunt current and distribution of calculated battery voltage are shown in the results. It is concluded that the impedance of the battery stack can be obtained by the experimental results of the transient response and self-discharge measurements. The capacity lose …

Effects Of Carbon Interlayer On Electrochemical Performance Of Lithium-Sulfur Cell, Jin-Peng Yu, Ming Zhang, Fei Ding, Zhi-Yuan Tang, Xing-Jiang Liu

Journal of Electrochemistry

Three kinds of conductive carbon films were prepared with Super-P (SP), KB and MWCNTs, and then the as-prepared carbon films were applied as an interlayer between a sulfur electrode and a separator for constructing a coin-type lithium-sulfur (Li-S) cell, respectively. The assessment results show that all the cells delivered the reversible capacities higher than 800 mAh·g^-1 after 40 cycles when the sulfur loading was up to 80% (by mass) in the sulfur electrode. Due to significant differences of physical properties among the carbon materials, the cell with a KB interlayer exhibited higher electrochemical polarization; the cycling performance of the …

Effect Of Al-Doping In Li-Rich Material Li1.2Mn0.543Co0.078Ni0.155Al0.030O2 For Lithium-Ion Batteries, Xiao-Xi Jin, Yi-Xiao Li, Yong Yang, Zhou-Cheng Wang

Journal of Electrochemistry

The Al-doped 0.5Li₂MnO₃·0.5Li(Mn_0.4Co_0.2Ni_0.4)O₂ compounds were successfully synthesized as cathode materials for lithium-ion batteries. The pristine and Al-doped materials were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), inductively coupled plasma-atomic emission spectrometry (ICP-AES) and laser Raman spectroscopy. The results indicated that all the prepared materials were indexed as a hexagonal structure with R-3m space group, and Al element had been introduced into lattice. When cycled at 180 mA·g^-1 (1 C-rate), the capacity retention of 4% (by mole) Al-doped 0.5Li₂MnO₃·0.5Li(Mn_0.4Co_0.2Ni …

Electrocatalytic Oxidation Of Glycerol At The Platinum Electrode Modified With An Nd-Fe-Moo42- Cyano-Bridged Mixed Coordination Polymer, Yong-Jun Ma, Yu-Xiu Tian, Jing Liu, Min Zhou, Jing Ding, Zhi-Mei Jin, Xiang-Mei Wang

Journal of Electrochemistry

A platinum electrode decorated with the ordered Nd-Fe-MoO₄^2- cyano-bridged mixed coordination polymer was successfully prepared by electrodeposition in virtue of the lyotropic liquid crystal soft template methods, and electrocatalytic oxidation behavior of glycerol was investigated on the chemically modified electrode by cyclic voltammetry. The influences of experimental factors such as the concentrations of H⁺ and SO₄^2- in electrolytes, glycerol concentration and scan rate on the electrocatalytic activity of glycerol at the modified electrode were also studied. It indicated that the proper amount of SO₄^2- in weakly acidic electrolyte could help to improve the …

Application Of Ionic Liquid Pp14Tfsi In Electrolyte Systems For Rechargeable Mg Batteries, Jin-Jie Zhu, Fei-Fei Wang, Yong-Sheng Guo, Jun Yang, Yan-Na Nuli, Jiu-Lin Wang

Journal of Electrochemistry

A phenolated-based Mg salt was prepared. The mixture of THF and N-methyl-N-butyl-piperidinium bis(trifluoromethanesulfonyl)imide (PP14TFSI) serves as the mixed solvent instead of pure THF for rechargeable Mg batteries systems. This new type of electrolyte system not only has optimal reversibility of Mg, but also owns a wide electrochemical window (2.7 V vs. Mg) and high ionic conductivity (7.77 mS·cm^-1). More importantly, the addition of Ionic Liquid suppresses the volatility of THF and improves the safety of rechargeable Mg batteries. The result shows that the mixture of THF and piperidyl-based Ionic Liquid could be regarded as a good solvent candidate …

Electro-Catalytic Oxidation Of Hydrogen Peroxide On Au/ L-Methionine /Gc Electrode, Jian-Feng Fan, Xue-Mei Luo, Jing Li, Lou-Zhen Fan

Journal of Electrochemistry

The modified electrodes have been fabricated by generation of Au nanoparticle chains, which was produced by reaction between HAuCl4 and sodium citrate without any additional capping agents or surfactants. The self-assembled Au nanoparticles were attached to the surface of glassy carbon electrode (GCE) layer by layer, using L-methionine (L-Met), thiourea (TU), allyl thiourea (ATU) and polyvinylpyrrolidone (PVP) as a crosslinking agent, respectively. The experimental results showed that the electrochemical performance of the different modified electrodes varied in [Fe(CN)₆]^3-/4- solution. The Au/L-Met/GCE exhibited an excellent electrochemical property, which is superior to other modified electrodes. In addition, the catalysis …

Synthesis Of Platinum Nanocrystallites And Possible Electrocatalytic Properties For Methanol, Lei-Lei Lu, Bao-Zhong Du, Sha Sun, Jin-Fen Niu, Jie Zhao

Journal of Electrochemistry

Platinum nanocrystallites were synthesized by the colloidal method using oxamide as the stabilizer. The morphologies and electrocatalytic performances for methanol of platinum nanocrystallites prepared at different pH values and with different reactant ratios of precursor and stabilizer were investigated. It was found that the platinum nanocrystallites synthesized at pH=5 and with the reactant ratio of 1:20 showed the best electrocatalytic activity for methanol. The peak current density reached up to 1709 μA·cm^-2. Furthermore, the electrocatalytic activity of platinum nanocrystallites for methanol reduced significantly although the cyclic voltammograms in the blank solution were not obviously changed after exposing in …

Thermo-Electric Generator Evaluation Board, Jeanette Brooks, Cody Sullivan, Adrian Rothenbuhler

College of Engineering Presentations

Thermoelectric generators (TEGs) are solid-state devices that convert temperature gradients into electrical energy. TEGs are desirable sources of energy as they require low maintenance and have high reliability with potential for use in low power and remote applications. To date, no simple and affordable, common test platform for evaluating the performance of TEGs in their associated environment exists. This project is aimed at providing such a platform to deliver performance data that is crucial in power budgeting and viability studies of TEG-powered applications. The design utilizes the common LTC3109 converter chip and an off-the-shelf micro-controller for temperature and load current …

Generation Of Bipolar Nanosecond Pulses, Sambasiva Rao Rajulapati

Electrical & Computer Engineering Theses & Dissertations

Bipolar pulse generation has been studied using transmission line technology, which was mainly used for monopolar pulse generation. In this thesis, low impedance, high current, nanosecond pulse generators were designed, constructed and tested. Five transmission lines were connected in parallel, so the impedance was 10 n. The transmission lines were switched by a spark gap switch operated in air. The closing of the switch creates a matched condition on one side of the transmission lines and a short circuit on the other side of the transmission lines. When the transmission lines are precharged, one of the two waves in opposite …

Position/Speed Sensorless Control For Permanent-Magnet Synchronous Machines, Yue Zhao

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

Permanent-magnet synchronous machines (PMSMs) are widely used in industrial applications owing to their distinctive advantages, such as high efficiency, high power density, and wide constant power region. To achieve high-performance field oriented control, accurate rotor position information, which is usually measured by rotary encoders or resolvers, is indispensable. However, the use of these sensors increases the cost, size, weight, and wiring complexity and reduces the mechanical robustness and the reliability of the overall PMSM drive systems. The goal of the research for this dissertation was to develop a rotor position/speed sensorless control system with performance comparable to the sensor-based control …

An Adaptive Kalman Filter For Voltage Sag Detection In Power Systems, Hisham Odeh Alrawashdeh

Dissertations

The exact values of the noise covariance matrix of the Kalman filter state vector Q and the measured signal noise covariance matrix R must be obtained in order to achieve the optimal performance of the Kalman filter. There have been many techniques and assumptions made to evaluate and compute Q and R. The effects of Q and R are investigated in detail in this dissertation. Based on these investigations, the Kalman filter has been modeled to detect the fundamental signal amplitude variations of power system signals. This technique helps in evaluating voltage sags in power systems.

Two algorithms are …

Co2 Recycling Using Microalgae For The Production Of Fuels, Michael H. Wilson, John Groppo, Andrew Placido, S. Graham, S. A. Morton Iii, Eduardo Santillan-Jimenez, Aubrey Shea, Mark Crocker, Czarena Crofcheck, Rodney Andrews

Center for Applied Energy Research Faculty and Staff Publications

CO₂ capture and recycle using microalgae was demonstrated at a coal-fired power plant (Duke Energy’s East Bend Station, Kentucky). Using an in-house designed closed loop, vertical tube photobioreactor, Scenedesmus acutus was cultured using flue gas as the CO₂ source. Algae productivity of 39 g/(m² day) in June–July was achieved at significant scale (18,000 L), while average daily productivity slightly in excess of 10 g/(m² day) was demonstrated in the month of December. A protocol for low-cost algae harvesting and dewatering was developed, and the conversion of algal lipids—extracted from the harvested biomass—to diesel-range hydrocarbons via catalytic …