Power and Energy Commons^™

Research Progress Of Key Components In Lithium-Sulfur Batteries, Jia-Jia Chen, Quan-Feng Dong

Journal of Electrochemistry

Due to the much higher theoretical specific capacity and energy density than the ones of traditional lithium ion battery, Li-S batteries have long been at the pinnacle in the realms of high-energy Li-metal batteries. However, the complicated electrochemical reactions on the sulfur cathode and Li anode, induced by the thermodynamic and kinetic behaviors of lithium polysulfides, are the intrinsic bottleneck to realize the full potential of Li-S batteries for practical application. In this review, we firstly discuss the roles, and thermodynamic and kinetic behaviors of polysulfides in the charging and discharging processes of Li-S batteries. Then, the functional design and …

Cybersecurity Strategy Against Cyber Attacks Towards Smart Grids With Pvs, Fangyu Li, Maria Valero, Liang Zhao, Yousef Mahmoud

KSU Proceedings on Cybersecurity Education, Research and Practice

Cyber attacks threaten the security of distribution power grids, such as smart grids. The emerging renewable energy sources such as photovoltaics (PVs) with power electronics controllers introduce new potential vulnerabilities. Based on the electric waveform data measured by waveform sensors in the smart grids, we propose a novel cyber attack detection and identification approach. Firstly, we analyze the cyber attack impacts (including cyber attacks on the solar inverter causing unusual harmonics) on electric waveforms in distribution power grids. Then, we propose a novel deep learning based mechanism including attack detection and attack diagnosis. By leveraging the electric waveform sensor data …

Parallel And Asynchronous Distributed Optimization For Power Systems Operation, Ali Mohammadi

LSU Doctoral Dissertations

Distributed optimization approaches are gaining more attention for solving power systems energy management functions, such as optimal power flow (OPF). Preserving information privacy of autonomous control entities and being more scalable than centralized approaches are two primary reasons for developing distributed algorithms. Moreover, distributed/ decentralized algorithms potentially increase power systems reliability against failures of components or communication links.

In this dissertation, we propose multiple distributed optimization algorithms and convergence performance enhancement techniques to solve the OPF problem. We present a multi-level optimization algorithm, based on analytical target cascading, to formulate and solve a collaborative transmission and distribution OPF problem. This …

Research And Simulation Of Dc Microgrid Three-Phase Ac-Dc Converter Control Strategy Based On Double Loop, Boning Wu, Zhiqiang Gao, Xuesong Zhou, Youjie Ma, Chenglong Wang

Electrical and Computer Engineering Faculty Publications

The new voltage and current double loop control strategy is proposed to solve the DC microgrid bus voltage fluctuation caused by loads fluctuation, parameters perturbation and unbalanced three-phase power supply. Firstly, the dq axis mathematical model of three-phase AC-DC bidirectional converter in DC microgrid is analyzed and established, and then the controllers are designed according to the dq axis mathematical model. The outer loop is a voltage loop based on variable gain linear extended state observer (VGLESO) and sliding mode theory. VGLESO can not only effectively overcome the problem of peak output of traditional high-gain LESO in the initial stage …

Design Optimization And Comparison Of Direct-Drive Outer-Rotor Srms Based On Fast Current Profile Estimation And Transient Fea, Vandana Rallabandi, Peng Han, Jie Wu, Aaron M. Cramer, Dan M. Ionel, Ping Zhou

Power and Energy Institute of Kentucky Faculty Publications

Outer-rotor switched reluctance machines (SRMs) have drawn much attention as promising candidates for in-wheel direct-drive motors of future electric vehicles. This article presents a systematic performance comparison of three outer-rotor SRM topologies for in-wheel traction applications in terms of the specific torque, electromagnetic efficiency, torque ripple, radial force, and mechanical aspects. A generalized design optimization framework for SRMs is proposed to enable the fast evaluation of large numbers of designs generated from the differential evolution by incorporating an analytical current profile estimation into the transient finite element analysis. The relationship between the saliency ratio and converter volt-ampere rating is also …

Sun’Iy Neyron Tarmoqdan Foydalanib Elektr Sistemasini Tahlil Qilish, Nuriddin Nurali O'G'Li Normamatov, Muzaffar Burxonovich Xudayorov

Acta of Turin Polytechnic University in Tashkent

Annotatsiya — Hozirgi kunda elektr energiyasi misli ko'rilmagan o'zgarishni boshdan kechirmoqda. So'nggi vaqtlarda hamma sohada sun'iy intellekt usullaridan foydalanishga katta e'tibor beriladi. Bo'lim maqolalarida beshta shinadagi aktiv va reaktiv quvvat yuklamalari berilib, har bir shinadagi ishlash va boshqaruvning og'ishi burchagini aniqlashni Nyuton - Rafson va Sun'iy Neyron Tarmoq usulidan foydalanib echilgan. Dastur, Sun'iy Neyron Tarmoq usulida topilgan natijalar Nyuton - Rafson usuli bilan taqoslangan.

Resistive Switching In Fto/Cuo-Cu2o/Au Memory Devices, Amir Shariffar, Haider Salman, Tanveer A. Siddique, Wafaa Gebril, M. Omar Manasreh

Electrical Engineering Faculty Publications and Presentations

Memristors are considered to be next-generation non-volatile memory devices owing to their fast switching and low power consumption. Metal oxide memristors have been extensively investigated and reported to be promising devices, although they still suffer from poor stability and laborious fabrication process. Herein, we report a stable and power-efficient memristor with novel heterogenous electrodes structure and facile fabrication based on CuO-Cu2O complex thin films. The proposed structure of the memristor contains an active complex layer of cupric oxide (CuO) and cuprous oxide (Cu2O) sandwiched between fluorine-doped tin oxide (FTO) and gold (Au) electrodes. The fabricated memristors demonstrate bipolar resistive switching …

Evaluation Of Bearing Voltage Reduction In Electric Machines By Using Insulated Shaft And Bearings, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Bearing voltages and corresponding currents in electric machines driven by pulse width modulation (PWM) converters with fast switching and high dv/dt can cause premature bearing failures. This paper evaluates the bearing voltage reduction by using insulated shafts and bearings. An equivalent circuit representation of electric machines taking into account high-frequency effects is developed to show the production mechanism of bearing voltage, based on which simulations are performed with detailed finite element models for transient and simplified equivalent circuit for steady-state analysis. The steady-state equivalent circuit is then calibrated, by combined numerical calculations and experimental measurements, and used to predict the …

Combined Numerical And Experimental Determination Of Ball Bearing Capacitances For Bearing Current Prediction, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel

Electrical and Computer Engineering Faculty Publications

High-frequency voltages across the steel ball bearings and the corresponding currents can cause premature bearing failures in electric machines driven by PWM converters. The bearing voltage, one of the most commonly-used failure indicators, depends heavily on the bearing capacitance. This paper presents a combined numerical and experimental approach for the calculation of ball bearing capacitances to address the uncertainty introduced by lubricant property, lubrication status and other metal parts, such as seals and ball retainers. Based on the obtained capacitance breakdown, the influences of temperature, speed and bearing load (radial, axial or combined) on the capacitance are studied. Measurements and …

Trust-Based User Interface Design For Islanded Alternating Current Microgrids, Yuliya Matlashova

Electrical and Computer Engineering ETDs

Futuristic microgrid systems may be capable of providing extensive information to the operator. As microgrid systems become more pervasive there will be a need to adjust the information an operator requires, to provide an optimized user-interface. In this paper, a combinatorial optimization strategy is used to provide an optimal user-interface for the microgrid operator that selects information for display depending on the operator's trust level in the system, and the assigned task. We employ a method based in sensor placement by capturing elements of the interface as different sensors, that find an optimal set of sensors via combinatorial optimization. However, …

Electric Drives With Wide Bandgap Devices For Two-Phase Very Low Inductance Machines, Yibin Zhang, Damien Lawhorn, Peng Han, Aaron M. Cramer, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Slotless and coreless machines with low inductance and low core losses are attractive for high speed and high power density applications. With the increase in fundamental frequency, typical drive implementations using conventional silicon-based devices are performance limited and also produce large current and torque ripples. This paper presents a systematic study of proposed drive configurations implemented with wide bandgap (WBG) devices in order to mitigate such issues for 2-phase very low inductance machines. Two inverter topologies, i.e., a dual H-bridge inverter with maximum redundancy and survivability and a 3-leg inverter for reduced cost, are considered. Feasible modulation schemes are derived …

Optimal Study Of A High Specific Torque Vernier-Type Axial-Flux Pm Machine With Two Different Stators And A Single Winding, Murat G. Kesgin, Peng Han, Narges Taran, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

This paper presents the optimal study of a verniertype axial-flux permanent-magnet (AFPM) machine, which has a high-polarity spoke-type PM rotor, a wound stator with a low number of coils, and a profiled stator. Both stators have profiled teeth to enhance the magnetic interaction between the rotor PM array and stator windings for torque production. Compared to the topology with two wound stators, the studied one has a smaller total axial length and is expected more suitable for applications where the space is limited in axial direction. Both topologies are optimized through 3-dimensional (3D) finite element analysis (FEA) by the combined …

Demand Response Of Hvacs In Large Residential Communities Based On Experimental Developments, Huangjie Gong, Evan S. Jones, Rosemary E. Alden, Andrew G. Frye, Donald G. Colliver, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Heating, ventilation, and air-conditioning (HVAC) systems contribute the largest electricity usage for a residential community. Modeling of the HVAC systems facilitate the study of demand response (DR) at both the residential and the power system level. In this paper, the equivalent thermal model of a reference house was proposed. Parameters for the reference house were determined based on the systematic study of experimental data obtained from fully instrumented field demonstrators. The aggregated HVAC load was modeled based on the reference house while considering a realistic distribution of HVAC parameters derived from data that was provided by one of the largest …

Electric Power System Studies For A Multi-Mw Pv Farm And Large Rural Community With Net Zero Energy And Microgrid Capabilities, Evan S. Jones, Oluwaseun M. Akeyo, Keith Waters, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Solar photovoltaic (PV) systems are currently being deployed at an accelerated rate because of their cost-competitiveness and environmental benefits, which make them a prime candidate for local renewable energy generation in communities. Microgrids can help accommodate for the problems that accompany PV systems, such as intermittency due to weather, by coordinating different distributed energy resources (DERs), while islanded or by drawing power from the utility while in grid-connected mode. An islanding option is also important for resilience and grid fault mitigation, even if other DERs are not present within the system. This paper studies the potential benefits that a multi-MW …

Design Optimization Of Coreless Axial-Flux Pm Machines With Litz Wire And Pcb Stator Windings, Murat G. Kesgin, Peng Han, Narges Taran, Damien Lawhorn, Donovin Lewis, Dan M. Ionel

Electrical and Computer Engineering Faculty Publications

Coreless axial-flux permanent-magnet (AFPM) machines may be attractive options for high-speed and high-power-density applications due to the elimination of core losses. In order to make full use of the advantages offered by these machines and avoid excessive eddy current losses in windings, advanced technologies for winding conductors need to be employed to suppress the eddy effect, such as the Litz wire and printed circuit board (PCB). In this paper, the best practices for designing Litz wire/PCB windings are discussed and a brief survey of state of the art PCB winding technology is provided. Three coreless AFPM machines are mainly considered. …

On-Chip Nonreciprocal Components For Full-Duplex Communications And Gaussian Regulated Gate Driver For Electromagnetic Interference Reduction, Chang Yang

Electrical Engineering Theses and Dissertations

This dissertation is comprised of two unrelated design endeavors. The first one is about two CMOS nonreciprocal components: 1) an isolator and 2) a circulator. To make the components compact enough for the next generation communication systems with wide bandwidth, both components operate at 100 GHz band for full-duplex transceivers for ultra-high-data-rate millimeter-wave wireless communication. The proposed nonreciprocal structures are based on a time-domain modulation by signals at around 1/6 of the RF frequencies and spatial duplexing over the RF signal paths, demonstrating over 45 dB isolation in a bandwidth of 1.5 GHz over the tuning range of 85-110 GHz. …

Non-Conventional Vehicles As A Way Towards Carbon Neutrality In Iceland, Julia Sokolowska

Independent Study Project (ISP) Collection

Paris Agreement’s chief objective is to protect the Earth and its inhabitants from a point of no return, when the effects of climate change will be so intense that they will shift the equilibrium of ecosystems. The distinctiveness of this international environmental treaty is that it does not impose climate change mitigation measures, but rather allows nation states to create their own set of measures, the NDCs, to reach the global warming of ‘well below 2oC’ by the end of the century. Thus, Iceland has submitted its own NDC, the Climate Action Plan 2018-2030, which has an ambitious goal of …

Survey Of Dc-Dc Non-Isolated Topologies For Unidirectional Power Flow In Fuel Cell Vehicles, Mahajan Sagar Bhaskar, Vigna K. Ramachandaramurthy, Sanjeevikumar Padmanaban, Frede Blaabjerg, Dan M. Ionel, Massimo Mitolo, Dhafer Almakhles

Power and Energy Institute of Kentucky Faculty Publications

The automobile companies are focusing on recent technologies such as growing Hydrogen (H2) and Fuel Cell (FC) Vehicular Power Train (VPT) to improve the Tank-To-Wheel (TTW) efficiency. Benefits, the lower cost, `Eco' friendly, zero-emission and high-power capacity, etc. In the power train of fuel cell vehicles, the DC-DC power converters play a vital role to boost the fuel cell stack voltage. Hence, satisfy the demand of the motor and transmission in the vehicles. Several DC-DC converter topologies have proposed for various vehicular applications like fuel cell, battery, and renewable energy fed hybrid vehicles etc. Most cases, the DC-DC power converters …

Modified Fractional Order Sliding Mode Control For Speed Control Of Permanent Magnet Synchronous Motor, Fardila Mohd Zaihidee

Student Works (2020-2029)

In recent years, energy saving research activities have focused on electric motors and their systems since they are the main consumer of electricity in the industrial sector. Permanent magnet synchronous motor is known as a high-efficiency motor and slowly replacing induction motors in the industries. For speed control of PMSM, the sliding mode controller (SMC) has been widely used due to its robustness, high accuracy, and simplicity. The main disadvantage of the SMC method is the chattering phenomenon, which should be reduced or eliminated without compromising the controller’s robustness. Fractional order sliding mode speed control (FOSMC) of PMSM is proposed …

Design And Experiment Of A Sun-Powered Smart Building Envelope With Automatic Control, Qiliang Lin, Yanchu Zhang, Arnaud Van Mieghem, Yi-Chung Chen, Nanfang Yu, Yuan Yang, Huiming Yin

Electrical and Computer Engineering Faculty Research

A novel sun-powered smart window blind (SPSWB) system has been designed and developed for the smart control of building envelopes to achieve the optimal internal comfort with minimum energy expenditure. Its self-powered sensing, controlling, and actuation significantly simplify the installation and maintenance of the system. The energy is harvested by the attached thin-film photovoltaic cells, after which it is voltage-regulated for the permanent storage into a rechargeable battery with 55% energy efficiency. The excessive heat absorbed by the solar cells is dissipated by a PVdF-HFP porous coating with more than 9% temperature reduction. The smart control of the energy harvesting …

Optimal Distribution System Reconfiguration Incorporating Distributed Generation Based On Simplified Network Approach, Mohammad Al Samman

Student Works (2020-2029)

Network Reconfiguration (NR) and Distributed Generation (DG) are well-accepted strategies to minimize power loss and voltage deviation in the Electrical Distribution Network (EDN). Since the NR problem contains a huge combinational search space, most researchers applied meta-heuristic methods to attain optimal NR solution. However, meta-heuristic methods do not always guarantee optimal solution and furthermore they consume huge processing time. This occurs mainly due to (1) random solution’s initialization and (2) the verification of solution in each iteration to fulfill the operation constraints during the optimization process. Besides, solving the NR problem simultaneously with DG placement and sizing increases the computational …

Lstm Forecasts For Smart Home Electricity Usage, Rosemary E. Alden, Huangjie Gong, Cristinel Ababei, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

With increasing of distributed energy resources deployment behind-the-meter and of the power system levels, more attention is being placed on electric load and generation forecasting or prediction for individual residences. While prediction with machine learning based approaches of aggregated power load, at the substation or community levels, has been relatively successful, the problem of prediction of power of individual houses remains a largely open problem. This problem is harder due to the increased variability and uncertainty in user consumption behavior, which make individual residence power traces be more erratic and less predictable. In this paper, we present an investigation of …

The Effect Of High Efficiency Building Technologies And Pv Generation On The Energy Profiles For Typical Us Residences, Evan S. Jones, Rosemary E. Alden, Huangjie Gong, Andrew G. Frye, Donald G. Colliver, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

The penetrations of high efficiency technologies and photovoltaic (PV) generation are increasing in the residential sector. Technologies such as improved insulation and efficient HVAC systems significantly affect the energy profile of a house. This effect varies due to climate characteristics, i.e. temperature, solar radiation, relative humidity, and wind speeds. The effect of other technologies, such as efficient water heaters, lighting, or kitchen appliances, is mainly governed by human behavior, which may be represented by a schedule. This paper studies the performance of both climate-influenced and scheduled household devices among different levels of efficiency through combined computational and experimental methods. Three …

On The Feasibility Of Electrification For Large Mobile Cranes, Donovin Lewis, Damien Lawhorn, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Trends towards vehicle electrification to reduce dependence on fossil fuels and increase drive train efficiency have led vehicle manufacturers to seek out paths towards gradual hybridization. For heavy duty construction vehicles, electrification consists of two principle components: electric hybridization of the vehicle carrier and the vehicle's auxiliary function. Economic and physical feasibility for the transition to electrical replacements for critical system components is important for the gradual development of electrified systems. In this paper, we present an investigation into multiple pathways for the hybridization of mobile cranes paired with simulations that analyze the feasibility of system electrification. ADVISOR was used …

Cost Analysis Of Optimized Islanded Energy Systems In A Dispersed Air Base Conflict, Jay F. Pearson, Torrey J. Wagner, Justin D. Delorit

Faculty Publications

The United States Air Force has implemented a dispersed air base strategy to enhance mission effectiveness for near-peer conflicts. Asset dispersal places many smaller bases across a wide geographic area, which increases resupply requirements and logistical complexity. Hybrid energy systems reduce resupply requirements through sustainable, off-grid energy production. This paper presents a novel hybrid energy renewable delivery system (HERDS) model capable of (1) selecting the optimal hybrid energy system design that meets demand at the lowest net present cost and (2) optimizing the delivery of the selected system using existing Air Force cargo aircraft. The novelty of the model’s capabilities …

Recent Progress In Bifunctional Catalysts For Zinc-Air Batteries, Neng-Neng Xu, Jin-Li Qiao

Journal of Electrochemistry

Zinc-air battery has attracted great attention from researchers due to its high energy density and power density, which is expected to be widely used in energy conversion and storage. Air electrode as the core area of oxygen catalytic reaction is the focus of the entire zinc-air battery research. Recently, many research achievements have been made in non-noble metal bifunctional catalysts/electrodes with high activity, low cost and abundant species. In this review, we mainly focus on the reaction mechanism and the recent progress in non-noble metal oxide catalyst, carbon-based catalyst, and carbon-based transition metal compound composite and self-supporting electrode. In addition, …

Research Progress Of Metal-Nitrogen-Carbon Catalysts Toward Oxygen Reduction Reaction Inm Changchun Institute Of Applied Chemistry, Ming-Jun Xu, Jie Liu, Jun-Jie Ge, Chang-Peng Liu, Wei Xing

Journal of Electrochemistry

The development of highly active and stable catalysts toward oxygen reduction reaction (ORR) has been facing severe challenges. In recent years, pyrolytic M-N-C catalysts and metal-organic framework derived materials made the performance of non-noble metal catalysts greatly improved, however, the molecular and atomic level understanding in the reaction active sites and the mechanism are still lacking. Here, we summarize the recent research progress made in the Changchun Institute of Applied Chemistry. We present a microporous metal-organic-framework confined strategy toward the preferable formation of ORR catalysts. Firstly, we studied the active site and proposed a new active site structure for the …

Electrochemical Carbon Dioxide Reduction In Flow Cells, Jia Fan, Na Han, Yan-Guang Li

Journal of Electrochemistry

Electrochemical carbon dioxide reduction (CO₂RR) is an appealing approach to convert atmospheric CO₂ to value-added fuels and industrial chemicals, and may play an important role during the transition to a carbon-neutral economy. In order to make this technology commercially viable, it is essential to pursue CO₂RR in flow reactors instead of conventional H-type reactors, and to combine electrocatalyst development with system engineering. In this review, we overview the cell configurations and performance advantages of the two types of flow reactors, analyze their shortcomings, and discuss the effects of their different components including gas diffusion electrode …

Electrolyte Tailoring For Electrocatalytic Reduction Of Stable Molecules, Jin-Han Li, Fang-Yi Cheng

Journal of Electrochemistry

Reduction of stable molecules such as CO₂ and N₂ is important process in electrochemical energy conversion and storage technologies for electrofuels production. However, for the inert nature of CO₂/N₂ molecule and competitive proton reduction in conventional aqueous electrolytes, selective electrochemical carbon/nitrogen fixation suffers from high overpotential, low reaction rate and low selectivity. While addressing these issues has witnessed substantial advances in electrocatalysts, much less attention has been placed on the electrolytes, which play an important role in regulating the local environment and thus the performance of catalysts under operating conditions. Rational design of electrolytes has …

Fuel Cell Performance Of Non-Precious Metal Based Electrocatalysts, Yan-Feng Zhang, Fei Xiao, Guang-Yu Chen, Min-Hua Shao

Journal of Electrochemistry

The commercialization of proton exchange membrane fuel cells (PEMFCs) is hindered by high cost and low durability of Pt based electrocatalysts. Developing efficient and durable non-precious metal catalysts is a promising approach to addressing these conundrums. Among them, transition metals dispersed in a nitrogen (N)-doped carbon support (M-N-C) show good oxygen reduction reaction activity. This article reviews recent progress in M-N-C catalysts development, focusing on the catalysts design, membrane electrode assembly fabrication, fuel cell performance, and durability testing. Template-assisted approach is an efficient way to synthesize M-N-C materials with homogeneously dispersed single atom active site and reduced metal particles, carbides …