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Articles 1 - 26 of 26
Full-Text Articles in Power and Energy
Report On The First Year Of Operation Of Kentucky’S First Utility Wind Turbine, Lawrence E. Holloway, Sophia A. Hahn, Aron Patrick
Report On The First Year Of Operation Of Kentucky’S First Utility Wind Turbine, Lawrence E. Holloway, Sophia A. Hahn, Aron Patrick
Electrical and Computer Engineering Faculty Publications
This report examines the first year’s operational data from Kentucky’s first utility wind turbine, the 37 m hub-height 90-kilowatt NPS100C-27, operated by the PPL Corporation Research and Development at their Renewable Integration Research Facility in Mercer County, Kentucky. During that year, the turbine was available 95% of the time, spinning 85% of the time, and generating power 78% of the time, and had a net capacity factor of 11%. This report analyzes the turbine performance and uses the collected wind data to project the performance of an example turbine more typical of larger commercial turbines recently installed elsewhere in the …
The Rhythm Of Renewables: Minute-By-Minute Insights From Kentucky, David S. Beyerle, Noah M. Stewart, Shaun E. Lavin, Chad C. Alkire, Heather Nikolic, Samuel Kelty, Ezekiel A. Boggs, Declan Boyle, Lawrence E. Holloway, Aron Patrick
The Rhythm Of Renewables: Minute-By-Minute Insights From Kentucky, David S. Beyerle, Noah M. Stewart, Shaun E. Lavin, Chad C. Alkire, Heather Nikolic, Samuel Kelty, Ezekiel A. Boggs, Declan Boyle, Lawrence E. Holloway, Aron Patrick
Electrical and Computer Engineering Faculty Publications
Kentucky’s renewable energy landscape beats with a distinct rhythm shaped by ever-changing variations in sunlight, wind, rainfall, and the ever-modernizing grid that connects them. This paper analyzes minute-by-minute performance data from seven renewable and storage assets owned and operated by the PPL Corporation in Kentucky, including hydroelectric, solar, wind, and lithium-ion battery systems. Using a full year of synchronized, high-resolution data from multiple sites in the Commonwealth, the study examines daily and seasonal capacity factor trends, explores correlations among generation types, and evaluates their alignment with utility load profiles. Our analysis found 279 hours—about 3.2% of the year—with zero renewable …
Recent Advances Of Wind-Solar Hybrid Renewable Energy Systems For Power Generation: A Review, Pranoy Roy, Jiangbiao He, Tiefu Zhao, Yash Veer Singh
Recent Advances Of Wind-Solar Hybrid Renewable Energy Systems For Power Generation: A Review, Pranoy Roy, Jiangbiao He, Tiefu Zhao, Yash Veer Singh
Electrical and Computer Engineering Faculty Publications
A hybrid renewable energy source (HRES) consists of two or more renewable energy sources, such as wind turbines and photovoltaic systems, utilized together to provide increased system efficiency and improved stability in energy supply to a certain degree. The objective of this study is to present a comprehensive review of wind-solar HRES from the perspectives of power architectures, mathematical modeling, power electronic converter topologies, and design optimization algorithms. Since the uncertainty of HRES can be reduced further by including an energy storage system, this paper presents several hybrid energy storage system coupling technologies, highlighting their major advantages and disadvantages. Various …
Artificial Intelligence Method For The Forecast And Separation Of Total And Hvac Loads With Application To Energy Management Of Smart And Nze Homes, Rosemary E. Alden, Huangjie Gong, Evan S. Jones, Cristinel Ababei, Dan M. Ionel
Artificial Intelligence Method For The Forecast And Separation Of Total And Hvac Loads With Application To Energy Management Of Smart And Nze Homes, Rosemary E. Alden, Huangjie Gong, Evan S. Jones, Cristinel Ababei, Dan M. Ionel
Electrical and Computer Engineering Faculty Publications
Separating the HVAC energy use from the total residential load can be used to improve energy usage monitoring and to enhance the house energy management systems (HEMS) for existing houses that do not have dedicated HVAC circuits. In this paper, a novel method is proposed to separate the HVAC dominant load component from the house load. The proposed method utilizes deep learning techniques and the physical relationship between HVAC energy use and weather. It employs novel long short-term memory (LSTM) encoder-decoder machine learning (ML) models, which are developed based on future weather data input in place of weather forecasts. In …
Equivalent Electric And Heat-Pump Water Heater Models For Aggregated Community-Level Demand Response Virtual Power Plant Controls, Huangjie Gong, Tim Rooney, Oluwaseun M. Akeyo, Brian T. Branecky, Dan M. Ionel
Equivalent Electric And Heat-Pump Water Heater Models For Aggregated Community-Level Demand Response Virtual Power Plant Controls, Huangjie Gong, Tim Rooney, Oluwaseun M. Akeyo, Brian T. Branecky, Dan M. Ionel
Electrical and Computer Engineering Faculty Publications
Advanced control techniques may be used to establish a virtual power plant to regulate the operation of electric water heaters, which may be regarded as a “uni-directional battery” and a major component of a hybrid residential energy storage system. In order to estimate the potential of regulating water heaters at the aggregated level, factors including user behavior, number of water heaters, and types of water heaters must be considered. This study develops generic water heater load curves based on the data retrieved from large experimental projects for resistive electric water heaters (EWHs) and heat pump water heaters (HPWHs). A community-level …
Improving The Power Outage Resilience Of Buildings With Solar Pv Through The Use Of Battery Systems And Ev Energy Storage, Huangjie Gong, Dan M. Ionel
Improving The Power Outage Resilience Of Buildings With Solar Pv Through The Use Of Battery Systems And Ev Energy Storage, Huangjie Gong, Dan M. Ionel
Electrical and Computer Engineering Faculty Publications
Buildings with solar photovoltaic (PV) generation and a stationary battery energy storage system (BESS) may self-sustain an uninterrupted full-level electricity supply during power outages. The duration of off-grid operation is dependent on the time of the power fault and the capabilities of the home energy management system (HEMS). In this paper, building resilience is quantified by analyzing the self-sustainment duration for all possible power outages throughout an entire year. An evaluation method is proposed and exercised on a reference house in California climate zone 9 for which the detailed electricity usage is simulated using the EnergyPlus software. The influence of …
Study Of Renewable Energy Penetration On A Benchmark Generation And Transmission System, Oluwaseun M. Akeyo, Aron Patrick, Dan M. Ionel
Study Of Renewable Energy Penetration On A Benchmark Generation And Transmission System, Oluwaseun M. Akeyo, Aron Patrick, Dan M. Ionel
Electrical and Computer Engineering Faculty Publications
Significant changes in conventional generator operation and transmission system planning will be required to accommodate increasing solar photovoltaic (PV) penetration. There is a limit to the maximum amount of solar that can be connected in a service area without the need for significant upgrades to the existing generation and transmission infrastructure. This study proposes a framework for analyzing the impact of increasing solar penetration on generation and transmission networks while considering the responses of conventional generators to changes in solar PV output power. Contrary to traditional approaches in which it is assumed that generation can always match demand, this framework …
Parameter Identification For Cells, Modules, Racks, And Battery For Utility-Scale Energy Storage Systems, Oluwaseun M. Akeyo, Vandana Rallabandi, Nicholas Jewell, Aron Patrick, Dan M. Ionel
Parameter Identification For Cells, Modules, Racks, And Battery For Utility-Scale Energy Storage Systems, Oluwaseun M. Akeyo, Vandana Rallabandi, Nicholas Jewell, Aron Patrick, Dan M. Ionel
Electrical and Computer Engineering Faculty Publications
The equivalent circuit model for utility-scale battery energy storage systems (BESS) is beneficial for multiple applications including performance evaluation, safety assessments, and the development of accurate models for simulation studies. This paper evaluates and compares the performance of utility-scale equivalent circuit models developed at multiple sub-component levels, i.e. at the rack, module, and cell levels. This type of modeling is used to demonstrate that the equivalent circuit model for a reference cell, module, or rack of a BESS can be scaled to represent the entire battery system provided that the battery management system (BMS) is active and functional. Contrary to …
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
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 …
Combined Numerical And Experimental Determination Of Ball Bearing Capacitances For Bearing Current Prediction, Peng Han, Greg Heins, Dean Patterson, Mark Theile, Dan M. Ionel
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 …
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
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. …
Co-Optimization Approach To Post-Storm Recovery For Interdependent Power And Transportation Systems, Yinyin Ge, Lili Du, Hongzing Ye
Co-Optimization Approach To Post-Storm Recovery For Interdependent Power And Transportation Systems, Yinyin Ge, Lili Du, Hongzing Ye
Electrical and Computer Engineering Faculty Publications
The power and transportation systems are urban interdependent critical infrastructures (CIs). During the post-disaster restoration process, transportation mobility and power restoration process are interdependent, and their functionalities significantly affect other well-beings of other urban CIs. Therefore, to enhance the resilience of urban CIs, successful recovery strategies should promote CI function cooperatively and synergistically to distribute goods and services efficiently. This paper develops an integrative framework that addresses the challenges of enhancing the recovery efficiency of urban power and transportation systems in short-term recovery period. Specifically, the post-storm recovery process is considered as a scheduling problem under the constraints representing crew …
An Accurate And Efficient Time Delay Estimation Method Of Ultra-High Frequency Signals For Partial Discharge Localization In Substations, Pengfei Li, Kejie Dai, Tong Zhang, Yantao Jin, Yushun Liu, Yuan Liao
An Accurate And Efficient Time Delay Estimation Method Of Ultra-High Frequency Signals For Partial Discharge Localization In Substations, Pengfei Li, Kejie Dai, Tong Zhang, Yantao Jin, Yushun Liu, Yuan Liao
Electrical and Computer Engineering Faculty Publications
Partial discharge (PD) localization in substations based on the ultra-high frequency (UHF) method can be used to efficiently assess insulation conditions. Localization accuracy is affected by the accuracy of the time delay (TD) estimation, which is critical for PD localization in substations. A review of existing TD estimation methods indicates that there is a need to develop methods that are both accurate and computationally efficient. In this paper, a novel TD estimation method is proposed to improve both accuracy and efficiency. The TD is calculated using an improved cross-correlation algorithm based on full-wavefronts of array UHF signals, which are extracted …
Surrogate Affine Approximation Based Co-Optimization Of Transactive Flexibility, Uncertainty, And Energy, Hongzing Ye
Surrogate Affine Approximation Based Co-Optimization Of Transactive Flexibility, Uncertainty, And Energy, Hongzing Ye
Electrical and Computer Engineering Faculty Publications
This study presents an approach to co-optimization of transactive flexibility, energy, and optimal injection-range of Variable Energy Resource (VER). Flexibility receives immense attention, as it is the essential resource to accommodate VERs in modern power systems. With a novel concept of transactive flexibility, the proposed approach proactively positions the flexible resources and optimizes the demand of flexibility. A surrogate affine approximation (SAA) method is proposed to solve the problem with variable infinite-constraint range in polynomial time. It is shown that SAA is more optimistic than the traditional affine policy in the power literature. The SAA method is also applicable to …
Fault Identification And Location For Distribution Network With Distributed Generations, Wen Fan, Yuan Liao
Fault Identification And Location For Distribution Network With Distributed Generations, Wen Fan, Yuan Liao
Electrical and Computer Engineering Faculty Publications
Power distribution networks with distributed generations may experience faults. It is essential to promptly locate the fault for fast repair and restoration. This paper presents a novel method for identifying the faulted section and accurate location of faults that occur on power distribution grid. Appropriate matrices are set up to represent meter locations on the grid and the topology of the grid. The voltage and current measurements obtained are utilized to decide the fault sections. Then fault location is determined by solving equations that link measurements and fault locations through bus impedance matrix. The method is applicable to both single …
Accurate Location Of Evolving Faults On Transmission Lines Using Sparse Wide Area Measurements, Xiangqing Jiao, Yuan Liao
Accurate Location Of Evolving Faults On Transmission Lines Using Sparse Wide Area Measurements, Xiangqing Jiao, Yuan Liao
Electrical and Computer Engineering Faculty Publications
In electric power systems, not all fault conditions remain unchanged during faults. An evolving fault has one characteristic initially and changes to a different condition subsequently. Locating evolving faults is challenging due to the change in fault type shortly after the fault initiation. This paper presents a new approach for estimating the locations of evolving faults on transmission lines. By using sparse wide area voltage measurements, this method is able to accurately locate evolving faults without requiring measurements from either end of the faulted line. There is no need to detect whether a fault is an evolving fault or not. …
Efficient Planar Heterojunction Perovskite Solar Cells With Li-Doped Compact Tio2 Layer, Detao Liu, Shibin Li, Peng Zhang, Yafei Wang, Rui Zhang, Hojjatollah Sarvari, Feng Wang, Jiang Wu, Zhiming Wang, Zhi Chen
Efficient Planar Heterojunction Perovskite Solar Cells With Li-Doped Compact Tio2 Layer, Detao Liu, Shibin Li, Peng Zhang, Yafei Wang, Rui Zhang, Hojjatollah Sarvari, Feng Wang, Jiang Wu, Zhiming Wang, Zhi Chen
Electrical and Computer Engineering Faculty Publications
Perovskite solar cells (PSCs) have been developed rapidly in recent time, and efficient planar PSCs are regarded as the most promising alternative to the Si solar cells. In this study, we demonstrated that Li-doping of compact TiO2 can reduce the density of electron traps and increase the conductivity of the electron transport layer (ETL) of PSCs. Due to the improved electronic property of ETL, the Li-doped compact TiO2 based planar heterojunction PSCs exhibit negligible hysteretic J-V behavior. Comparing with the undoped compact TiO2 based PSCs, the power conversion efficiency (PCE) of the Li-doped compact TiO2 film …
A Robust Decentralized Load Frequency Controller For Interconnected Power Systems, Lili Dong, Yao Zhang, Zhiqiang Gao
A Robust Decentralized Load Frequency Controller For Interconnected Power Systems, Lili Dong, Yao Zhang, Zhiqiang Gao
Electrical and Computer Engineering Faculty Publications
A novel design of a robust decentralized load frequency control (LFC) algorithm is proposed for an inter-connected three-area power system, for the purpose of regulating area control error (ACE) in the presence of system uncertainties and external disturbances. The design is based on the concept of active disturbance rejection control (ADRC). Estimating and mitigating the total effect of various uncertainties in real time, ADRC is particularly effective against a wide range of parameter variations, model uncertainties, and large disturbances. Furthermore, with only two tuning parameters, the controller provides a simple and easy-to-use solution to complex engineering problems in practice. Here, …
Dynamic Companion Harmonic Circuit Models For Analysis Of Power Systems With Embedded Power Electronics Devices, H. Garcia, M. Madrigal, B. Vyakaranam, R. Rarick, F. Eugenio Villaseca
Dynamic Companion Harmonic Circuit Models For Analysis Of Power Systems With Embedded Power Electronics Devices, H. Garcia, M. Madrigal, B. Vyakaranam, R. Rarick, F. Eugenio Villaseca
Electrical and Computer Engineering Faculty Publications
In this paper a methodology that extends the dynamic harmonic domain (DHD) analysis of large networks is presented. The method combines DHD analysis and discrete companion circuit modeling resulting in a powerful analytic technique called dynamic companion harmonic circuit modeling. It provides for a complete dynamic harmonic analysis of the system while preserving the advantages of discrete companion circuit models. The methodology is illustrated by its application to a three-node power system, where reactive power compensation is achieved using a fixed-capacitor, thyristor-controlled reactor (FC-TCR) and its control system.
Randomcast: An Energy-Efficient Communication Scheme For Mobile Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das
Randomcast: An Energy-Efficient Communication Scheme For Mobile Ad Hoc Networks, Sunho Lim, Chansu Yu, Chita R. Das
Electrical and Computer Engineering Faculty Publications
In mobile ad hoc networks (MANETs), every node overhears every data transmission occurring in its vicinity and thus, consumes energy unnecessarily. However, since some MANET routing protocols such as dynamic source routing (DSR) collect route information via overhearing, they would suffer if they are used in combination with 802.11 PSM. Allowing no overhearing may critically deteriorate the performance of the underlying routing protocol, while unconditional overhearing may offset the advantage of using PSM. This paper proposes a new communication mechanism, called RandomCast, via which a sender can specify the desired level of overhearing, making a prudent balance between energy and …
Power Analysis And Optimization Techniques For Energy Efficient Computer Systems, Wissam Chedid, Chansu Yu, Ben Lee
Power Analysis And Optimization Techniques For Energy Efficient Computer Systems, Wissam Chedid, Chansu Yu, Ben Lee
Electrical and Computer Engineering Faculty Publications
Reducing power consumption has become a major challenge in the design and operation of to-day’s computer systems. This chapter describes different techniques addressing this challenge at different levels of system hardware, such as CPU, memory, and internal interconnection network, as well as at different levels of software components, such as compiler, operating system and user applications. These techniques can be broadly categorized into two types: Design time power analysis versus run-time dynamic power management. Mechanisms in the first category use ana-lytical energy models that are integrated into existing simulators to measure the system’s power consumption and thus help engineers to …
Storage And Delivery Constrained Unit Commitment, Y. Al-Kalaani, F. Eugenio Villaseca, F Renovich Jr
Storage And Delivery Constrained Unit Commitment, Y. Al-Kalaani, F. Eugenio Villaseca, F Renovich Jr
Electrical and Computer Engineering Faculty Publications
A general formulation and the development of a dynamic programming algorithm to solve a fuel-constrained unit commitment problem is presented. The system under consideration has oil units with storage constraints, gas units with delivery constraints, and unconstrained coal units. An optimal approach to transfer the fuel delivery constraints into unit capacity limits using a closed-form dual dispatch is introduced. As a result, the gas units can be viewed as fuel-unconstrained, thus greatly reducing complexity. It is shown that the optimization problem, which requires that storage levels be parameterized, leads to two different dispatch rules. The oil units are dispatched to …
Transient Stability Test Systems For Direct Stability Methods, V. Vittal, D Martin, R Chu, J Fish, J C. Giri, C K. Tang, F. Eugenio Villaseca, R G. Farmer
Transient Stability Test Systems For Direct Stability Methods, V. Vittal, D Martin, R Chu, J Fish, J C. Giri, C K. Tang, F. Eugenio Villaseca, R G. Farmer
Electrical and Computer Engineering Faculty Publications
A standard set of power system data with benchmark results are presented against which direct stability techniques to assess transient stability can be compared and tested. The test systems have been selected to display a wide range of dynamic characteristics to provide a robust test of the efficacy and accuracy of the various analytical techniques to analyze transient stability. Transient stability test system data and benchmark results obtained from two commercially available time-domain stability analysis packages are presented
Transient Stability Hierarchical Control In Multimachine Power Systems, A Rubbai, F. Eugenio Villaseca
Transient Stability Hierarchical Control In Multimachine Power Systems, A Rubbai, F. Eugenio Villaseca
Electrical and Computer Engineering Faculty Publications
The authors present the optimal transient stability control problem in a hierarchical structure for multimachine power systems. The two-level structure retains the local closed-loop controls, thereby easing its implementation on existing systems. The formulation accounts for nonlinearities and interconnections, and the optimization of the system transient performance is obtained with less computational effort. Since the computations are distributed among the many local feedback subsystems, the storage and solution times are considerably less than those required by a single overall centralized controller. This advantage becomes much stronger as the system size increases. For illustration purposes, this technique was applied successfully to …
Fast Thermal Generation Rescheduling, F. Eugenio Villaseca, B. Fardanesh
Fast Thermal Generation Rescheduling, F. Eugenio Villaseca, B. Fardanesh
Electrical and Computer Engineering Faculty Publications
A new dynamic programming algorithm for fast rescheduling thermal generation is presented. The savings in computational times are brought about by the introduction of two new techniques: the variable truncation dynamic programming and the limitation of the solution space to be searched. Several examples on a 20 machine system are used to illustrate the application of the algorithm and to show that optimal solutions are obtained at significantly reduced computational times.
Two-Step Optimal Thermal Generation Scheduling, B Fardanesh, F. Eugenio Villaseca
Two-Step Optimal Thermal Generation Scheduling, B Fardanesh, F. Eugenio Villaseca
Electrical and Computer Engineering Faculty Publications
A new approach to the solution of the optimal thermal generation scheduling problem is presented. The problem is solved in two steps. As a first step, the optimal production schedule for the next day is obtained based on a daily load forecast, reserve capacity requirements, and present status of generating units. The second-step algorithm uses the results of the first step and adjusts the previous schedule to meet new constraints developed during the course of the day. Variable truncation dynamic programming is proposed as a new method to reduce computation effort. To eliminate the need for solving the …