Power and Energy Commons^™

Energy-Efficient Smart Home System: Optimization Of Residential Electricity Load Management System, Sangeun Sarah Cho

Renée Crown University Honors Thesis Projects - All

In this project, an algorithm for electrical load management in a hypothetical household setting is proposed, developed and simulated. There are two main goals for the algorithm; firstly, to minimize the total electricity cost when a variable pricing model is applied; secondly, to flatten the demand curve over 24 hours, which, when applied to real-life settings, will minimize investment costs for the utilities – including building more generation plants and transmission lines – as well as the total bill for customers. To simulate the algorithm, mathematical models for appliances are developed based on typical usage and operation patterns.

Design, Layout, And Testing Of A Silicon Carbide-Based Under Voltage Lock-Out Circuit, Michael Dalan Glover

Graduate Theses and Dissertations

Silicon carbide-based power devices play an increasingly important role in modern power conversion systems. Finding a means to reduce the size and complexity of these systems by even incremental amounts can have a significant impact on cost and reliability. One approach to achieving this goal is the die-level integration of gate driver circuitry with the SiC power devices. Aside from cost reductions, there are significant advantages to the integration of the gate driver circuits with the power devices. By integrating the gate driver circuitry with the power devices, the parasitic inductances traditionally seen between the gate driver and the switching …

Voltage Stability Analysis Using Simulated Synchrophasor Measurements, Allan Agatep

Master's Theses

An increase in demand for electric power has forced utility transmission systems to continuously operate under stressed conditions, which are close to instability limits. Operating power systems under such conditions along with inadequate reactive power reserves initiates a sequence of voltage instability points and can ultimately lead to a system voltage collapse. Significant research have been focused on time-synchronized measurements of power systems which can be used to frequently determine the state of a power system and can lead to a more robust protection, control and operation performance. This thesis discusses the applicability of two voltage stability synchrophasor-based indices from …

Modeling And Analysis Of A Dynamic Voltage Regulator, Timothy David Haskell

Master's Theses

Increased government funding and incentives in recent years has led to an increase in the number of grid-tied renewable energy sources as their economic benefits become more renowned. Unfortunately, the outputs of these renewable resources are often highly variable, resulting in undesirable voltage disruptions that are harmful to sensitive loads. In addition to the energy variability of renewable energy sources, random voltage sags, swells and disruptions are already a major issue in power systems. Recent advances in power electronic devices have provided a platform for new solutions to the voltage support problem in power systems. One promising solution is the …

Modeling And Analysis Of A Pv Grid-Tied Smart Inverter's Support Functions, Benjamin Anders Johnson

Master's Theses

The general trends in the past decade of increasing solar cell efficiency, decreasing PV system costs, increasing government incentive programs, and several other factors have all combined synergistically to reduce the barriers of entry for PV systems to enter the market and expand their contribution to the global energy portfolio. The shortcomings of current inverter functions which link PV systems to the utility network are becoming transparent as PV penetration levels continue to increase. The solution this thesis proposes is an approach to control the inverters real and reactive power output to help eliminate the problems associated with PV systems …

Intermediate Band Solar Cells Based On Inas Quantum Dots Embedded In Ingaas Quantum Well, Ramesh Vasan

Graduate Theses and Dissertations

Intermediate band solar cells based on quantum dots and quantum wells with anti-reflection coating are investigated in this thesis. The demand for high efficient solar cells as an alternate source of energy is the main motivation for this research project. Intermediate band solar cells based on quantum dots were the subject of intensive research in recent years. High power conversion efficiency was predicted from InAs/GaAs intermediate band solar cells as the presence of InAs quantum dots increased the absorption below the band gap of the host material.

In this thesis, an attempt has been made to further increase the absorption …

Synthesis Of Optimized Inp/Zns Core/Shell Nanocrystals And Tio2 Nanotubes For Quantum Dot Sensitized Solar Cells, Seungyong Lee

Graduate Theses and Dissertations

Synthesis of InP/ZnS core/shell nanocrystals and TiO₂ nanotubes and the optimization study to couple them together were explored for quantum dot sensitized solar cells. Its intrinsic nontoxicity makes the direct band gap InP/ZnS core/shell be one of the most promising semiconductor nanocrystals for optoelectric applications, with the advantage of tuning the optical absorption range in the desired solar spectrum region. Highly luminescent and monodisperse InP/ZnS nanocrystals were synthesized in a non-coordinating solvent. By varying the synthesis scheme, different size InP/ZnS nanocrystals with emission peaks ranging from 520 nm to 620 nm were grown. For the purpose of ensuring air …

Hydrothermal Synthesis Of Pure Li4Ti5O12 And Its Electrochemical Performance, Wen-Jun Xie, Yu-Shi He, Hong Wang, Xiao-Zhen Liao, Zi-Feng Ma

Journal of Electrochemistry

Spinel Li₄Ti₅O₁₂ was prepared by hydrothermal method using commercial anatase (TiO₂) and lithium hydroxide (LiOH) as raw materials. The effects of the LiOH concentration of lithium hydroxide, hydrothermal reaction time and calcination temperature on the structure and electrochemical performance of Li₄Ti₅O₁₂ were investigated. The formation process of Li₄Ti₅O₁₂ was also proposed. The micro-structure and morphology wereas characterized by XRD, SEM, TEM techniques, and the electrochemical performance was analyzed by galvanostatic charge-discharge test. The results show that the pure phase spinel Li₄Ti …

Preparation And Catalytic Properties Of Feco Alloy Nanocatalyst, Ming-Xuan Li, Jie-Lian Ou, Sheng-Pei Chen, Peng Wang, Bin-Bin Xu, Shi-Gang Sun

Journal of Electrochemistry

The FeCo alloy nanoparticles were electrodeposited on glassy carbon electrode by chronoamperometry and were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the shapes of FeCo nanoparticles were cubes with an average size of 65 nm. The atom ratio of Fe and Co is 1:1. As indicated from the pattern of selected area electron diffraction (SAED), the FeCo cubic nanoparticles were single crystal which belonged to body-centered cubic with an interval of 0.201 nm referring to the (110) facets of FeCo alloy. The FeCo cubic nanoparticles exhibited the enhanced electrocatalytic …

Electrochemical Performance Of Lifepo4/C Synthesized Via Aqueous Solution-Evaporation Route, Ning-Yu Gu, Xing-Hua He, Yang Li

Journal of Electrochemistry

The LiFePO₄/C samples have been synthesized via an aqueous solution-evaporation route with LiH₂PO₄, FeC₂O₄.2H₂O as raw materials and citric acid as a carbon source. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) were used to analyze structure and morphology of the samples. The electrochemical performances of the LiFePO₄/C cathodes were characterized by charge/discharge cures and electrochemical impedance spectroscopy (EIS). The results show that the LiFePO₄/C sample, calcined at 700 °C and contained 3.03% (by mass) carbon, exhibited a highly pure …

Preparation And Methanol Electrooxidation Of Pt/Pmo12/Pedot/Gc Electrodes, Jing-Hua Ma, Rui-Xiang Wang, Yi-Liang Tan, Shan-Shan Wang, Yan-Qin Zhang, You-Jun Fan

Journal of Electrochemistry

Modification of phosphomolybdic acid (PMo₁₂) on poly(3,4-ethylenedioxythiophene) (PEDOT) film (PEDOT/GC) obtained through the electrochemical polymerization was performed using adsorption method (PMo₁₂/PEDOT/GC), followed by electrodepositing Pt on PMo₁₂/PEDOT/GC to prepare Pt/PMo₁₂/PEDOT/GC electrode. Effects of PMo₁₂ and PEDOT on the methanol oxidation performance of electrode were investigated. Results showed that PMo₁₂ obviously changed the morphology and structure of Pt loaded on the electrode, leading to the formation of sharp thorns at the edge of Pt nanostructures. Cyclic voltammetry and chronoamperometry data demonstrated that the catalytic activities of methanol electrooxidation on the Pt/PMo …

Synthesis Of Lifepo4/C Cathode By Sol-Gel And Calcining Method With Chitosan Monomer, Jia Xu, Yan-Yan Wang, Rui Wang, Bo Wang, Yue Pan, Dian-Xue Cao, Gui-Ling Wang

Journal of Electrochemistry

The LiFePO₄/C cathode materials for Li-ion battery were synthesized by sol-gel and calcining method using chitosan monomer as a carbon source and a gelating agent. The structures and morphologies were characterized by X-ray diffraction spectroscopy (XRD) and scanning electron microscopy (SEM). The electrochemical performance was investigated by the galvanostatic charge–discharge test. When the molar ratios between chitosan monomer and LiFePO₄ were 1:1.2, the LiFePO₄/C cathode calcined at 600 ^oC showed the best performance. The particle sizes ranged 200 ～ 400 nm. The initial discharge capacity of 155 mAh·g-¹ was achieved at room temperature …

Properties Of Carbon Coated Tin Negative Electrode For Lithium-Ion Battery, Gui-Chang Liu, Xiao-Xiao Shen, Li-Da Wang

Journal of Electrochemistry

Carbon coated tin power was prepared by decomposing glucose applying a hydrothermal method, and was further used as the active material for negative electrode of lithium secondary battery. Charge-discharge tests show that the carbon coated tin electrode with the addition of 5 wt.% acetylene black as a conductive agent could obtain an initial discharge capacity of 967 mAh·g^-1 and a discharge capacity of 362 mAh·g^-1 after 50 cycles, which is much higher than that of tin electrode (166 mAh·g^-1 after 50 cycles). The coated carbon hinders the agglomeration of tin powder, reduces the irreversible capacity loss of …

Electrochemical Synthesis Of Hierarchical Dendritic Polyaniline Nanostructures, Shao-Huang Weng, Jian-Zhang Zhou, Zhong-Hua Lin, Xin-Hua Lin

Journal of Electrochemistry

In this work, the p-TSA doped and hierarchical dendritic nanostructured polyanilines (PANI) have been prepared by potentiostatic electropolymerization without using any templates at room temperature. The mechanism of the polymerization has been discussed according to the electrodeposition curves. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were employed to confirm the formation of uniform hierarchical dendritic structure on PANI. UV-Vis spectroscopy (UV-Vis) and infrared spectroscopy (FTIR) proved that the prepared PANI is in the form of emeraldine salt. The templateless electrodeposition method is simple, easy to operate, can be applied to fabricate other nanostructures of conducting polymers.

Synthesis And Electrocatalysis Of Pdcu Alloy Nanocrystals, Hai-Bin Wu, Rui-Zhong Zhang, Wei Chen

Journal of Electrochemistry

Monodispersed PdCu alloy nanoparticles were synthesized by co-reduction of Cu(acac)2 and Pd(acac)2 with 1, 2-hexadecanediol. The spherical and popcorn-like shapes of PdCu alloy nanoparticles were obtained by changing the ratios of mixed surface protecting ligands of 1-octadecene, and oleylamine or oleic acid. TEM and XRD measurements showed that both PdCu nanoparticles are alloy nanocrystals dominated with (111) planes and the average sizes are 12.7 ± 0.18 and 20.4 ± 0.31 nm for he spherical and popcorn-like PdCu nanoparticles, respectively. The electrocatalytic activities of the PdCu nanocrystals for formic acid oxidation were evaluated by electrochemical cyclic voltammetry (CV). The result showed …

A Comparative Study Of Ce3+/Ce4+ Redox Couple On Pt Electrode In Sulfuric Acid And Methanesulfonic Acid, Zhao-Hua Li, You-Qun Chu, Chun-An Ma

Journal of Electrochemistry

The electrochemical oxidations of Ce³⁺ to Ce⁴⁺ on Pt rotating disk electrode (RDE) in both sulfuric acid and methanesulfonic acid (MSA) solutions were studied by using cyclic voltammetry and linear sweep voltammetry. The complexing behaviors of Ce³⁺/Ce⁴⁺ were preliminarily probed and the exchange current density, diffusion coefficient, as well as reaction rate constant were obtained from Butler-Volmer equation. The activation energies of Ce³⁺ oxidation on Pt electrode in two types of acidic media, obtained from Arrhenius equation, were also compared. The results indicate that Ce³⁺ can be oxidized to Ce4+ much easier in …

Synthesis And Electrochemical Performance Of Si/C Composite Modified By Pani, Guang-Hui Zhang, Pei-Kang Shen, Ge Sang, Ren-Jin Xiong

Journal of Electrochemistry

Silicon/carbon (Si/C) composite materials were prepared through high-energy ball milling and high-temperature solid-phase method, and then coated with thin polyaniline (PAni) film by oxidation. The microstructure and component of the composites were characterized by SEM, XRD, IR, TG, and the electrochemical performance was investigated by cyclic voltammetry (CV) and galvanostatic charge-discharge tests. The results showed that the surface of PAni/Si/G/C composite was coating with complete lamellar structure of PAni film. Its reversible capacity was 784 mAh·g^-1 and 690 mAh·g^-1 could be maintained after 50th charge-discharge cycles.

Electrochemical Activities Of Oxygen-Doped Carbon Surface For V(Iv)/V(V) Redox Couple, Huan Zhang, Lin-Lin Qin, Yi-Ning Shi, Ming-Sen Zheng, Quan-Feng Dong, Zhao-Wu Tian

Journal of Electrochemistry

Graphite plate electrodes were treated with oxygen plasma and doped with oxygen as well as oxygen functional groups. With the treatment, the activities of graphite plate electrodes toward VO²⁺/VO₂⁺ redox reactions were improved. FT-IR and EDS analysis results indicated that oxygen functional groups were introduced to the surface of graphite plates after oxygen plasma treatment. In this paper, the graphite plate treated for 20 min showed the highest activity. The average charge efficiency reached 91%, suggesting an increase of 19%, compared with that of the untreated graphite plate under a current density of 8 mA·cm^{-2 …}

Solar Cell Design Using Metamaterials, Yang Liu, Yitung Chen, Jichun Li

College of Engineering: Graduate Celebration Programs

Natural structure with simultaneous negative permittivity and permeability has not been discovered yet. However, using specially-designed metal embedded in dielectric bodies can achieve a kind of artificial negative index. This periodic structure which is smaller than the guided wavelength is known as a metamaterial. However, recent designs of metamaterials have some disadvantages when they are used in the application of solar cell. The perfect absorption is only within a narrow band, and for most of the solar spectrum, the absorption is no more than 10%. Here, a new kind of absorber for the solar spectrum has been designed and analyzed, …

A Computation Model For Nanoantenna-Based Solar Cell With High Conversion Efficiency, Yiyan Li, Ke-Xun Sun, Yingtao Jiang

College of Engineering: Graduate Celebration Programs

• Build a model of spiral nanoantenna and an antenna
  array based solar cell collector.
• Using Rao-Wilton-Glisson (RWG) basis functions to
  simulate the spiral nanoantennas.
• We calculate the frequency response of the radiation
  gain as the indicator of receiving bandwidth which is a
  key factor in conversion efficiency.