Power and Energy Commons^™

Rapid Battery Interchange System, Mason Borda

Electrical Engineering

As our nation strives towards a departure from widespread use of fossil fuels, we must focus on a plan for what is to be the substitute for Internal Combustion Engine vehicles as well as the infrastructure to support this. The most popular alternative to the internal combustion engine is the electrically propelled vehicle, one that can provide us with many benefits including simplified construction, lower operational costs, and for the driving enthusiasts more torque. The prevailing issue in the widespread acceptance and use of the electric vehicle thus far is “range anxiety”. Range anxiety is defined as “The fear of …

Development Of Smart Pv Inverters For The Smart Grid, Yahia Baghzouz

NSTec UNLV Symposium

The Electric Grid has become more complex with recent technological developments. There are more alternative power sources and sensors added into the mix at every part of the grid. The Energy Meter has changed over the past several years as well. The older meters were checked only once a month with a meter reader, but the new "Smart" Meters are capable of reporting energy usage at fifteen minute intervals.

The Electrocatalytic Study Of Licoo2 In Air Electrode For Lithium-Air, Jun Gao, Wei Wu, Yan-Yan Tian, Yong Yang

Journal of Electrochemistry

The LiCoO₂ has been investigated as a new electrocatalyst for air electrodes using homemade lithium-air battery. The electrochemical performance and structural changes of the LiCoO₂ based composite air electrodes have been studied. The results of CV, XRD and charge-discharge tests show that the composite air electrodes composed of LiCoO₂ can greatly improve the discharge performance of lithium-air batteries. In particular when the composite air electrodes are charged to 4.1 V before further discharging, the obvious catalytic effects of LiCoO₂ are attributed to higher valence state of the Co element in LiCoO₂, esp. at charged …

Dissolved Oxygen Seawater Battery With Electrochemical Capacitance, Hai-Bo Xu, Yong-Hong Lu, Wei Zhang, Yan-Ting Yu, Chuan-Wei Yan, Ya-Ping Sun, Lian Zhong, Jian-Guo Liu, Yi Zheng, Bing Han, Yong-Liang Wang

Journal of Electrochemistry

A new concept of seawater battery with electrochemical capacitance (SWB-EC) has been proposed using carbon fibre brush (CFB) as the cathode material, and three testing prototypes have been made accordingly. The discharge performances of the CFB before- and after-oxidation and Mg alloy sacrifice anode were studied by cyclic voltammetry and constant current discharge tests under steady state conditions. Results show that the oxidized CFB exhibits the pseudo-capacitive characteristic and its activity of oxygen reduction reaction (ORR) in stirred seawater highly increases, comparing with the non-oxidized CFB. The open circuit potential of Mg alloy sacrifice anode is -1.74 V, having the …

Progress And Perspective Of Fuel Cell Technology, Ming Hou, Bao-Lian Yi

Journal of Electrochemistry

Fuel cell, a clean and high-efficiency electrochemical power source, has being paid much attention worldwide recent years. In this paper, the progress and perspective of fuel cell technology are elucidated in detail. Fuel cells have been applied in some special fields such as spacecraft, shuttle and submarines. However, in the areas of transportation, stationary station and portable power source, fuel cells are still under demonstration due to the durability and cost problems. The reliability and surrounding survivability of fuel cells should be enhanced in the special application. Meanwhile, the durability and cost of fuel cells are the main issues to …

Preparation And Electrochemical Performance Of Lifepo4/C By Spray Drying Method Assisted With Organic Template, Quan-Bing Liu, Yang-Mei Jiang, Hui-Yu Song, Shi-Jun Liao

Journal of Electrochemistry

In this work, the LiFePO₄/C composites were prepared by the spray drying and carbothermal method, and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge-discharge measurements. The effects of the organic assisted templates on the morphologies and electrochemical properties of the LiFePO₄/C composites were investigated. The results showed that the morphology and microstructure of the composites could be tuned by incorporating with the different templates. The morphology of the composite appeared to be solid microspheres if no organic template was added, while porous microspheres, nest-like …

Synthesis And Electrochemical Performance Of Xlifepo4·Yli3V2(Po4)3 Composites, Ping-Ping Ma, Zhi-Jian Liu, Jian-Hua Xia, Yu Chen, Pu Hu, Zhi-Chao Lu, Ding-Guo Xia

Journal of Electrochemistry

A series of xLiFePO₄·yLi₃V₂(PO₄)₃ composites were systematically synthesized through solid state reactions by variations in the proportions of LiFePO₄ and Li₃V₂(PO₄)₃. The properties of the prepared compounds were investigated using X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. The capacity of 162.7 mAh/g at 0.2 C rate was obtained with the relatively good cycle stability and good conductivity for 0.95LiFePO₄·0.05Li₃V₂(PO₄)₃ due to more uniformed distributed and smaller particle sizes.

Preparation And Characterization Of Mno/Tin Anode For Lithium Ion Batteries, Gao-Jie Xu, Hai-Yan Yang, Peng-Xian Han, Li-Xue Zhang, Ke-Jun Zhang, Chuan-Jian Zhang, Yu-Hua Fan, Cai-Feng Bi, Guang-Lei Cui

Journal of Electrochemistry

Manganese titanate (MnTiO₃) powder was prepared via a sol-gel method using manganese acetate and tetrabutyl titanate as raw materials, and citric acid as a chelating agent. Through high temperature nitridation of MnTiO₃ powder in ammonia, the MnO/TiN composite was obtained. The phase structure, composition and morphology of the composites were characterized by XRD, SEM and EDS. The electrochemical properties of the composite electrodes were studied by performing cyclic voltammetry, galvanostatic charge and discharge, and electrochemical impedance spectroscopy tests. The MnO/TiN electrode delivered specific capacities of 394 mAh·g^-1 and 146 mAh·g^-1 at the current density of …

Polar Field Oriented Control With 3rd Harmonic Injection, Martin Todd Hess

Master's Theses

Abstract

POLAR FIELD-ORIENTED CONTROL

with

3^RD HARMONIC INJECTION

Martin Todd Hess

Field Oriented Control (FOC), also known as vector control, is a widely used and well documented method for controlling Permanent-Magnet Synchronous Motors (PMSM) and induction motors. Almost invariably the orientation of the stator and rotor (field) fluxes are described in rectangular coordinates. In this thesis we explore the practicality of using polar coordinates.

Third harmonic injection is also a well-known technique that allows full utilization of the bus (DC-link), thus allowing the motor to run to full base speed without the use of field weakening. This technique potentially …

Managing The Future Energy Policy For Ireland: Examining The Role Of Nuclear Power, Declan Lynch, Angela Wright

Dept. of Organisation & Professional Development Publications

This study assesses the attitudes and opinions of Irish people towards the use of nuclear power, and specifically examines the concept that Ireland should use nuclear power to generate electricity in the future. Currently, Ireland has a prohibition on nuclear power, with little debate or discussion on same, and with scant amounts of information published on the subject as it relates to Ireland. Conversely, from an international perspective, there is a significant volume of literature available covering all aspects of nuclear power, generated from over 50 years of nuclear power operations. Nuclear power technology is perceived as being a relatively …

A New Method For Node Ranking For Voltage Stability In Power Systems, Hongxiang Li

Theses

The voltage collapse in power system is a major concern for reliable operation of these systems. In this thesis, a method is proposed to determine the load margins at load nodes (loadability limits). A good portion of the computation to obtain those margins is routinely done when solving the power flow problem, thus the computational effort is greatly reduced. The proposed method is based on the fact that when voltage collapse occurs the Jacobian matrix, that is calculated when performing power flow analysis, is singular. The relationships between the elements of the Jacobian matrix and the nodal powers are exploited …

Slides: Jisea Natural Gas Study: Potential U.S. Electric Power Futures, Jeffrey Logan

Drawing the Blueprint for a Sustainable Natural Gas Future (January 18)

Presenter: Jeffrey Logan, Denver Museum of Nature and Science

4 slides

Can Morphology Tailoring Improve The Open Circuit Voltage Of Organic Solar Cells?, Biswajit Ray, M. S. Lundstrom, Muhammad A. Alam

Birck and NCN Publications

While the effect of interfacial morphology on the short circuit current (I_SC) of organic photovoltaic devices (OPVs) is well known, its impact on open circuit voltage (V_OC) and fill-factor (FF) are less clear. Since the output power of a solar cell Pout = I_SCV_OCFF, such understanding is critical for designing high-performance, morphology-engineered OPVs. In this letter, we provide an explicit analytical proof that any effort to radically improve V_OC by tailoring bulk heterojunction morphology is futile, because any increase in ISC due to larger interface area is counterbalanced by corresponding increase …

Solar Photovoltaic System Modeling And Control, Qing Xia

Electronic Theses and Dissertations

To realize the benefits of grid-connected photovoltaic system, it is extremely important to reduce energy losses and improve reliability of grid-connected PV systems with high PV penetration. In this thesis, three different Maximum Power Point Tracking (MPPT) strategies named as Perturbation & Observation MPPT, Incremental Conductance MPPT and Fuzzy Logic Control MPPT have been analyzed, simulated and compared with each other to improve the efficiency of power conversion. A general discussion to counteract partial shading effect in several aspects is also provided in this thesis. In order to improve reliability of the system, an optimum current control loop with suitable …

Smart Grid Communications, Christopher W. Asbery

Theses and Dissertations--Electrical and Computer Engineering

Smart grid technologies are starting to be the future of electric power systems. These systems are giving the utilities detailed information about their systems in real time. One of the most challenging things of implementing smart grid applications is employing the communications into the systems. Understanding the available communications can help ease the transition to these smart grid applications. Many of the utility personnel are spending too much time trying to figure out which communication is better for their application or applications. So this thesis presents the different communication types available with discussing the different attributes in which these communication …

An Adaptive Utility Interactive Photovoltaic System Based On A Flexible Switch Matrix To Optimize Performance In Real-Time, Mahmoud Alahmad, Mohamed Amer Chaaban, Siu Kit Lau, Jonathan Shi, Jill Neal

Durham School of Architectural Engineering and Construction: Faculty Publications

Reconfigurable architectures are of great interest to system designers to improve the system’s operation and efficiency. In this paper, we propose an adaptive utility interactive photovoltaic (PV) system based on a novel Flexible Switch array Matrix topology. This proposed system maximizes the generated power in real-time in response to operational conditions such as shading, soiling, mismatches, and module failure among others. The proposed system is a compromise in the utilization of power conditioning equipment to maximize energy capture and system efficiency. Simulation results demonstrate an average 13% improvement in efficiency when compared with the central inverter topology performance. A prototype …

Technical Feasibility Of Storage On Large Dish Stirling Systems, Charles E. Andraka, K Scott Rawlinson, Nathan P. Siegel

Faculty Journal Articles

Dish-Stirling systems have been demonstrated to provide high-efficiency solar-only electrical generation, holding the world record at 31.25%. This high efficiency results in a system with a high possibility of meeting the DOE SunShot goal of $0.06/kWh. Current dish-Stirling systems do not incorporate thermal storage. For the next generation of non-intermittent and cost-competitive solar power plants, we propose a thermal energy storage system that combines latent (phase-change) energy transport and latent energy storage in order to match the isothermal input requirements of Stirling engines while also maximizing the exergetic efficiency of the entire system. This report takes an initial look at …

Characterization Of Deep Levels In N-Type And Semi-Insulating 4h-Sic Epitaxial Layers By Thermally Stimulated Current Spectroscopy, P. G. Muzykov, Ramesh Madhu Krishna, K. C. Mandal

Faculty Publications

No abstract provided.

Coupled Electromagnetic And Heat Transfer Model For Microwave Heating In Domestic Ovens, Krishnamoorthy Pitchai, Sohan Birla, Jeyamkondan Subbiah, D. D. Jones, Harshanardhan Thippareddi

Department of Food Science and Technology: Faculty Publications

Microwave ovens are used extensively for heating a variety of not-ready-to-eat food products. Non-uniform heating of foods in microwave ovens is a major concern in assuring microbiological safety of such products. The non-uniform heating of foods is attributed by complex interaction of microwaves with foods. To understand this complex interaction, a comprehensive model was developed to solve coupled electromagnetic and heat transfer equations using finite-difference time-domain based commercial software. The simulation parameters, cell size, heating time step, and number of iterations for steady state electromagnetic field were optimized. The model was validated by 30 s heating profile of a cylindrical …

White Light Led Load System, Ronald Lu, Benjamin Ng

Electrical Engineering

No abstract provided.