Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters,
2020
University of Denver
Experimental Evaluation Of Medium-Voltage Cascode Gallium Nitride (Gan) Devices For Bidirectional Dc–Dc Converters, Salah Salem H. Alharbi
Electronic Theses and Dissertations
As renewable energy sources, such as photovoltaic (PV) cells and wind turbines, are rapidly implemented in DC microgrids, energy storage systems play an increasingly significant role in ensuring uninterrupted power supply and in supporting the reliability and stability of microgrid operations. Power electronics, especially bidirectional DC–DC converters, are essential parts in distributed energy storage and alternative energy systems because of their grid synchronization, DC power management, and bidirectional power flow capabilities. While there is increasing demand for more efficient, compact, and reliable power converters in numerous applications, most existing power converters are hindered by traditional silicon (Si) based semiconductors, which …
Edge-Cloud Computing For Iot Data Analytics: Embedding Intelligence In The Edge With Deep Learning,
2020
The University of Western Ontario
Edge-Cloud Computing For Iot Data Analytics: Embedding Intelligence In The Edge With Deep Learning, Ananda Mohon M. Ghosh, Katarina Grolinger
Electrical and Computer Engineering Publications
Rapid growth in numbers of connected devices including sensors, mobile, wearable, and other Internet of Things (IoT) devices, is creating an explosion of data that are moving across the network. To carry out machine learning (ML), IoT data are typically transferred to the cloud or another centralized system for storage and processing; however, this causes latencies and increases network traffic. Edge computing has the potential to remedy those issues by moving computation closer to the network edge and data sources. On the other hand, edge computing is limited in terms of computational power and thus is not well suited for …
Fault Identification On Electrical Transmission Lines Using Artificial Neural Networks,
2020
University of Kentucky
Fault Identification On Electrical Transmission Lines Using Artificial Neural Networks, Christopher W. Asbery
Theses and Dissertations--Electrical and Computer Engineering
Transmission lines are designed to transport large amounts of electrical power from the point of generation to the point of consumption. Since transmission lines are built to span over long distances, they are frequently exposed to many different situations that can cause abnormal conditions known as electrical faults. Electrical faults, when isolated, can cripple the transmission system as power flows are directed around these faults therefore leading to other numerous potential issues such as thermal and voltage violations, customer interruptions, or cascading events. When faults occur, protection systems installed near the faulted transmission lines will isolate these faults from the …
Control Of A Grid-Tied Single-Phase Inverter For Renewable Energy Integration,
2020
Minnesota State University, Mankato
Control Of A Grid-Tied Single-Phase Inverter For Renewable Energy Integration, Dianzhi Yu
All Graduate Theses, Dissertations, and Other Capstone Projects
With increasing demand for generating electricity from clean energy, renewable energy sources (RESs), such as wind and solar, has gained much attention due to the clean and quiet characteristics. In many applications, connecting multiple RESs of different types (e.g., wind and solar), voltages, and capacities to a power grid or load is required. Single- phase inverters have been widely installed in residential power system to meet the full or partial load demand. In this work, multiport converters were developed for integrating multiple RESs, wind turbine and photovoltaic (PV) panel. Since the intermittent characteristic of the RESs, an energy storage device, …
Control Of Voltage-Source Converters Considering Virtual Inertia Dynamics,
2020
Georgia Southern University
Control Of Voltage-Source Converters Considering Virtual Inertia Dynamics, Tri Nguyen
College of Graduate Studies: Theses & Dissertations
Controlling power-electronic converters in power systems has significantly gained more attention due to the rapid penetration of alternative energy sources. This growth in the depth of penetration also poses a threat to the frequency stability of modern power systems. Photovoltaic and wind power systems utilizing power-electronic converters without physical rotating masses, unlike traditional power generations, provide low inertia, resulting in frequency instability. Different research has developed the control aspects of power-electronic converters, offering many control strategies for different operation modes and enhancing the inertia of converter-based systems. The precise control algorithm that can improve the inertial response of converter-based systems …
A Four-Port Dc-Dc Converter For A Hybrid Wind/Solar Energy System,
2020
Minnesota State University, Mankato
A Four-Port Dc-Dc Converter For A Hybrid Wind/Solar Energy System, Jiahong Ning
All Graduate Theses, Dissertations, and Other Capstone Projects
With the increasing demand for clean and hybrid energy in the last decades, more and more attentions are paid to the renewable energy, e.g., wind and solar energy. According to the International Energy Agency, solar power was growing-fastest source in the world. In a hybrid wind/solar system, power converters play an important role in in power management and the voltage regulation. Gradually, power systems have undergone a paradigm shift from centralized generation to distributed generation. Smart grid, which is a combination of power systems and communication networks, was proposed to allow power systems to fit the future system challenge. However, …
Virtual Impedance Based Decentralized Control For A Microgrid System,
2020
Minnesota State University, Mankato
Virtual Impedance Based Decentralized Control For A Microgrid System, Ramkrishna Mishan
All Graduate Theses, Dissertations, and Other Capstone Projects
As greenhouse gases produced from the conventional power plant causes global climate change, using renewable energy sources (RESs) in the future power system is inevitable. To minimize greenhouse gases emission, the interest in renewable grid or micro-grid is growing nowadays. In the microgrid, especially in AC microgrids, converters play an important role in many areas, including microgrid integration, uninterrupted power supply, and flexible alternating current transmission systems. Inverter plays an essential role in grid integration because it serves the interface between the energy source and the power grid. The important aspect of the inverter is control. This thesis studies several …
Lithium-Ion Battery And Beyond: Oxygen Vacancy Creation In Tungsten Trioxide And Surface Modification Of Lithium Metal,
2020
South Dakota State University
Lithium-Ion Battery And Beyond: Oxygen Vacancy Creation In Tungsten Trioxide And Surface Modification Of Lithium Metal, Rajesh Pathak
Electronic Theses and Dissertations
The graphite-based anode material has a low theoretical specific capacity of 371 mAh g-1. The transitional metal oxides (TMOs) are considered a better choice owing to their relatively higher specific capacity. Among TMOs, tungsten trioxide (WO3) is considered promising due to a higher specific capacity of 693 mAh g-1, low cost, mechanically stable, and eco-friendly. It has been a challenge to utilize the TMOs as anode materials as they suffer from poor electronic conductivity and large electrode volume expansion during discharge/charge cycles. In our first project, we demonstrate a unique self-recovery of capacity in reduced WO3 by the incorporation of …
Factors Affecting The Performance Of Photo-Voltaic Solar Energy Storage,
2020
University of Central Florida
Factors Affecting The Performance Of Photo-Voltaic Solar Energy Storage, Vasanth Bhat
Electronic Theses and Dissertations, 2020-2023
One of the most important factors in a nation's development is energy availability. All the aspects of its economy are directly proportional to the energy resources. Oil is one of the most sought energy resources currently. Solar energy is one of the most important renewable sources of energy available to us. With oil deposits depleting and current global warming, there is an emphasis on using more and more renewable sources or clean energy. This has led to immense research on solar cells and how it could better be used to get maximum output. Storage of energy is another aspect that …
Systematically Exploring The Effects Of Pole Count On The Performance And Cost Limits Of Ultrahigh Efficiency Fractional Hp Axial Flux Pm Machines,
2020
University of Kentucky
Systematically Exploring The Effects Of Pole Count On The Performance And Cost Limits Of Ultrahigh Efficiency Fractional Hp Axial Flux Pm Machines, Narges Taran, Vandana Rallabandi, Greg Heins, Dan M. Ionel
Power and Energy Institute of Kentucky Faculty Publications
Optimizing the design of electric machines is a vital step in ensuring the economical use of active materials. The three-dimensional (3-D) flux paths in axial flux permanent magnet (AFPM) machines necessitate the use of computationally expensive 3-D electromagnetic analysis. Furthermore, a large number of design evaluations is required to find the optimum, causing the total computation time to be excessively long. In view of this, a two-level surrogate assisted algorithm capable of handling such expensive optimization problems is introduced, which substantially reduces the number of finite element analysis (FEA) evaluations to less than 200 while conventional algorithms require thousands of …
An Intelligent Controlling Method For Battery Lifetime Increment Using State Of Charge Estimation In Pv-Battery Hybrid System,
2020
Edith Cowan University
An Intelligent Controlling Method For Battery Lifetime Increment Using State Of Charge Estimation In Pv-Battery Hybrid System, Md Ohirul Qays, Yonis Buswig, Hazrul Basri, Md Liton Hussain, Ahmed Abu-Siada, Md Momtazur Rahman, S. M. Muyeen
Research outputs 2014 to 2021
In a photovoltaic (PV)-battery integrated system, the battery undergoes frequent charging and discharging cycles that reduces its operational life and affects its performance considerably. As such, an intelligent power control approach for a PV-battery standalone system is proposed in this paper to improve the reliability of the battery along its operational life. The proposed control strategy works in two regulatory modes: maximum power point tracking (MPPT) mode and battery management system (BMS) mode. The novel controller tracks and harvests the maximum available power from the solar cells under different atmospheric conditions via MPPT scheme. On the other hand, the state …
Computational Intelligence Approaches For Energy Optimization In Microgrids,
2020
South Dakota State University
Computational Intelligence Approaches For Energy Optimization In Microgrids, Tamal Roy
Electronic Theses and Dissertations
The future electrical system termed as smart grid represents a significant paradigm shift for power industry. Nowadays, microgrids are becoming smarter with the integration of renewable energy resources (RESs) , diesel generators , energy storage systems (ESS), and plug-in electric vehicles (PEV or EV) . However, these integration bring with new challenges for intelligent management systems. The classical power generation approaches can no longer be applied to a microgrid with unpredictable renewable energy resources. To relive these problem, a proper power system optimization and a suitable coordination strategy are needed to balance the supply and demand. This thesis presents three …
Wind Power Forecasting Methods Based On Deep Learning: A Survey,
2020
Jiangsu University of Science and Technology
Wind Power Forecasting Methods Based On Deep Learning: A Survey, Xing Deng, Haijian Shao, Chunlong Hu, Dengbiao Jiang, Yingtao Jiang
Electrical & Computer Engineering Faculty Research
Accurate wind power forecasting in wind farm can effectively reduce the enormous impact on grid operation safety when high permeability intermittent power supply is connected to the power grid. Aiming to provide reference strategies for relevant researchers as well as practical applications, this paper attempts to provide the literature investigation and methods analysis of deep learning, enforcement learning and transfer learning in wind speed and wind power forecasting modeling. Usually, wind speed and wind power forecasting around a wind farm requires the calculation of the next moment of the definite state, which is usually achieved based on the state of …
Distributed Machine Learning Approach To Fast Frequency Response-Based Inertia Estimation In Low Inertia Grids,
2020
South Dakota State University
Distributed Machine Learning Approach To Fast Frequency Response-Based Inertia Estimation In Low Inertia Grids, Abodh Poudyal
Electronic Theses and Dissertations
Recent updates to the IEEE 1547-2018 standard allow active participation of distributed energy resources (DERs) in power grid services with the goal of increased grid reliability and resiliency. With the rapid growth of DERs towards a low inertia converter-dominated grid, the DERs can provide fast frequency response (FFR) services that can quickly counteract the change in system frequency through inertial support. However, in low voltage grids, frequency and voltage face dynamics coupling due to a high resistance to reactance ratio and cannot be controlled separately as in the bulk electric grid. Due to the coupling effect, the control of one …
ระยะเวลาบำรุงรักษาที่เหมาะสมสำหรับเครื่องปรับอากาศแบบแยกส่วน,
2020
บัณฑิตวิทยาลัย
ระยะเวลาบำรุงรักษาที่เหมาะสมสำหรับเครื่องปรับอากาศแบบแยกส่วน, เชาวลิต คำสุข
Chulalongkorn University Theses and Dissertations (Chula ETD)
งานวิจัยนี้มีวัตถุประสงค์เพื่อหาระยะเวลาที่เหมาะสมในการทำความสะอาดเครื่องปรับอากาศแบบแยกส่วน เนื่องจากประสิทธิภาพของเครื่องปรับอากาศที่ลดลงส่วนใหญ่มาจากสิ่งสกปรกที่เกาะติดที่แผงคอยล์เย็น และแผงคอยล์ร้อน ส่งผลให้ประสิทธิภาพของเครื่องปรับอากาศโดยรวมลดลง ดังนั้นการทำความสะอาดเครื่องปรับอากาศจะทำให้ประสิทธิภาพเพิ่มกลับคืนมาได้ในระดับหนึ่ง โดยประสิทธิภาพที่เพิ่มจะขึ้นอยู่กับความถี่ในการทำความสะอาดเครื่องปรับอากาศ ได้มีการศึกษาและจัดเก็บข้อมูลจากการเดินเครื่องปรับอากาศแบบแยกส่วนขนาดทำความเย็น 3.6 kW จำนวน 2 เครื่อง โดยมีการจัดเก็บข้อมูลในระยะเวลา 6 เดือน แยกประเภทการจัดเก็บข้อมูล เป็น 2 ประเภท คือ 1) เครื่องปรับอากาศเครื่องที่ 1 ล้างทำความสะอาดแล้วทำการเก็บข้อมูลทุกๆ 1 เดือน เป็นระยะเวลา 6 ครั้งโดยไม่ทำความสะอาดเพื่อหาการเสื่อมประสิทธิภาพเนื่องจากความสกปรก และ 2) เครื่องปรับอากาศเครื่องที่ 2 ล้างทำความสะอาดทุกเดือนทำให้เครื่องสะอาดอยู่เสมอเพื่อใช้ปรับแก้พลังไฟฟ้าเนื่องจากอุณหภูมิภายนอกที่เปลี่ยนไป และนำข้อมูลมาวิเคราะห์หาประสิทธิภาพ ซึ่งขึ้นกับตัวแปรอิสระที่ใช้ศึกษาคือ อุณหภูมิภายในห้องปรับอากาศ อุณหภูมิภายนอกห้อง ภาระทำความเย็น และความสกปรก การหาระยะเวลาที่เหมาะสมในการทำความสะอาดเครื่องปรับอากาศแบบแยกส่วนนั้น คิดจากราคาค่าใช้จ่ายต่ำสุดซึ่งประกอบด้วยค่าทำความสะอาดและค่าพลังงานไฟฟ้าที่เพิ่มขึ้นเนื่องจากความสกปรก จากการวิเคราะห์พบว่า อัตราการลดลงของประสิทธิภาพเครื่องปรับอากาศแบบแยกส่วน คือ ร้อยละ 3.01 ต่อเดือน และระยะเวลาที่เหมาะสมในการทำความสะอาดเครื่องปรับอากาศแบบแยกส่วน คือ ทุกๆ ระยะเวลา 3 เดือน
Optimization-Based Fast-Frequency Support In Low Inertia Power Systems,
2020
South Dakota State University
Optimization-Based Fast-Frequency Support In Low Inertia Power Systems, Ujjwol Tamrakar
Electronic Theses and Dissertations
The future electrical energy demand will largely be met by non-synchronous renewable energy sources (RESs) in the form of photovoltaics and wind energy. The lack of inertial response from these non-synchronous, inverter-based generation in microgrids makes the system vulnerable to large rate-of-change-of-frequency (ROCOF) and frequency excursions. This can trigger under frequency load shedding and cause cascaded outages which may ultimately lead to total blackouts. To limit the ROCOF and the frequency excursions, fast-frequency support can be provided through appropriate control of energy storage systems (ESSs). For proper deployment of such fast-frequency control strategies, accurate information regarding the inertial response of …
Tailoring The Grain Boundaries Of Wide-Bandgap Perovskite Solar Cells By Molecular Engineering,
2020
South Dakota State University
Tailoring The Grain Boundaries Of Wide-Bandgap Perovskite Solar Cells By Molecular Engineering, Khalid Emshadi
Electronic Theses and Dissertations
Due to the attraction of fabricating highly efficient tandem solar cells, wide-bandgap perovskite solar cells have attracted substantial interest in recent years. However, polycrystalline perovskite thin-films show the existence of trap states at grain boundaries, which diminish the optoelectronic properties of the perovskite and thus remains a challenge. This research demonstrates a one-step solution-processing of the [MA0.9Cs0.1Pb(I0.6Br0.4)3] wide-bandgap perovskite using Phenylhydrazine Iodide with amino groups to successfully passivate the trap density within grain boundaries and increase the perovskite grain size. The reinforced morphology and grain boundaries treatment considerably enhanced the photovoltaic performance …
Enhanced Charge Carrier Dynamics And Defects Passivation In Hybrid Perovskite Solar Cell Using A Novel Organic Halide Salt,
2020
South Dakota State University
Enhanced Charge Carrier Dynamics And Defects Passivation In Hybrid Perovskite Solar Cell Using A Novel Organic Halide Salt, Md Ashuqur Rahman Laskar
Electronic Theses and Dissertations
In the last few years, active research works on hybrid perovskite solar cells (HPSCs) have been going on throughout the world as a part of clean energy revolution. HPSCs have already proved their potentiality as future solar technology through their promising photovoltaic performances and ability for low temperature based solution processing. Nevertheless, still there are remaining challenges of better charge carrier dynamics and defects minimization in HPSCs. Overcoming these challenges are very important to achieve high power conversion efficiency (PCE) practically. Aiming this, a novel organic halide salt called Phenylhydrazinium Iodide (PHAI) is introduced as additive with CH3NH …
Surface And Structure Engineering For Next Generation Lithium Metal Batteries,
2020
South Dakota State University
Surface And Structure Engineering For Next Generation Lithium Metal Batteries, Ke Chen
Electronic Theses and Dissertations
Lithium (Li) metal has been considered as one of the most promising anode materials to replace conventional graphite for Li-ion battery due to its high theoretical capacity (3860 mAh g-1) and low electrochemical potential (-3.04 V vs standard hydrogen electrode). However, it still faces some problems such as unstable solid electrolyte interphase (SEI), uncontrolled Li dendrites growth, and infinite volume change during battery charging/discharging. To develop a stable and low-cost Li metal anode for next-generation Li metal battery, in this dissertation, we have made efforts to understand and solve these problems in two aspects, by introducing an artificial SEI and …
A Four-Port Bidirectional Dc-Dc Converter For Renewable Energy System And Microgrid,
2020
Minnesota State University, Mankato
A Four-Port Bidirectional Dc-Dc Converter For Renewable Energy System And Microgrid, Xia Du
All Graduate Theses, Dissertations, and Other Capstone Projects
Renewable energy has nowadays become important in electrical power applications. Power converters play an important role in integrating these distributed energy sources. However, due to their intermittence characteristics, e.g., the output power provided by the PV and wind turbine is not stable, either an energy storage system will be used or microgrid is formed between the main grid and the sources. To integrate these renewable energy sources and manage the power flow, a multiport converter is preferred because it is highly beneficial and cost-efficiently than the traditional solution that using multiple individual power converter for each source. This thesis proposed …
