Engineering Commons^™

Modeling Of A Multi-Megawatt Grid Connected Pv System With Integrated Batteries, Vandana Rallabandi, Oluwaseun M. Akeyo, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

The multi-megawatt grid connected photovoltaic (PV) system studied in the paper includes parallel arrays and power electronic units, each with their own DC-DC and DC-AC converters. In one configuration, the DC-AC converters of adjacent parallel sections are connected in cascade, in order to effectively operate as a multilevel inverter, thereby reducing the filtering requirements. Grid voltage oriented control is employed for inverters and a battery is incorporated for energy storage and performance improvement. Modeling is performed with the PSCAD/EMTDC software, such that both the power electronics components, controls and subsystem aspects, and the electric grid power system issues, can be …

Capture And Recycle Of Industrial Co2 Emissions Using Mircoalgae, Michael H. Wilson, Daniel T. Mohler, John G. Groppo, Thomas E. Grubbs, Stephanie Kesner, E. Molly Frazar, Aubrey Shea, Czarena L. Crofcheck, Mark Crocker

Center for Applied Energy Research Faculty and Staff Publications

A novel cyclic flow photobioreactor (PBR) for the capture and recycle of CO₂ using microalgae was designed and deployed at a coal-fired power plant (Duke Energy’s East Bend Station). The PBR was operated continuously during the period May–September 2015, during which algae productivity of typically 0.1–0.2 g/(L day) was obtained. Maximum CO₂ capture efficiency was achieved during peak sunlight hours, the largest recorded CO₂ emission reduction corresponding to a value of 81 % (using a sparge time of 5 s/min). On average, CO₂ capture efficiency during daylight hours was 44 %. The PBR at East Bend …

On The Feasibility Of Carbon Nanotube Windings For Electrical Machines — Case Study For A Coreless Axial Flux Motor, Vandana Rallabandi, Narges Taran, Dan M. Ionel, John F. Eastham

Power and Energy Institute of Kentucky Faculty Publications

The latest developments in carbon nanotube (CNT) wires and yarns attract great interest for potential application to electromagnetic devices, such as electrical machines and transformers. The CNT material properties are largely different from copper and aluminum in terms of electrical conductivity, mass density, and thermal transfer, creating a new design paradigm for which the traditional rules and device topologies no longer apply. This paper proposes a brushless permanent magnet multidisc axial flux construction with coreless stator and special windings and minimal rotor back iron, as a suitable topology for CNT winding application. Specific analytical closed-form sizing equations, as a function …

Large-Scale Optimization Of Synchronous Reluctance Machines Using Ce-Fea And Differential Evolution, Yi Wang, Dan M. Ionel, Vandana Rallabandi, Minjie Jiang, Steven Stretz

Power and Energy Institute of Kentucky Faculty Publications

A novel automated design optimization procedure based on the application of an ultrafast computationally efficient finite-element analysis (CE-FEA) for current-regulated synchronous reluctance machines supplied from power electronic converters is proposed. The CE-FEA uses only a minimum number of magnetostatic solutions in order to comprehensively evaluate performance, including ripple torque and core losses. The optimization algorithm is based on differential evolution, and uses as independent variables the torque angle and ratios for a generic rotor topology with four flux barriers. Two problems, one with two and the other with three objectives, are studied and results are compared. Global performance indices and …

Hybrid Diesel-Electric Drivetrain For Small Agricultural Field Machines, Joseph Jackson, Joseph S. Dvorak

Biosystems and Agricultural Engineering Faculty Publications

In this project, a series electric drivetrain sized for small agricultural machinery was developed and tested. Electric drives have noted benefits in simplicity, controllability, integration with other electronics such as those that provide autonomous action, and in efficiency over a wide operating range. Their biggest drawback for agricultural use is the limited capacity of electrical energy storage. A series hybrid drivetrain provides a method to overcome these capacity constraints through the use of chemical energy storage. The series hybrid drivetrain in this research was designed using well-established components. It consisted of a diesel-electric generator, a lead acid battery pack, a …

Cable Sizing And Its Effect On Thermal And Ampacity Values In Underground Power Distribution, Obinna E. Igwe

Theses and Dissertations--Electrical and Computer Engineering

Over the past decade, underground power distribution has become increasingly popular due to its reliability, safety, aesthetic characteristics, as well as the ever increasing focus on the environmental impacts of the various stages of power generation and distribution. With the technological advances in this area, the process of running these cables have become more economical and efficient.

This thesis explores the practice of grouping multiple three phase cables in a common conduit, using the duct bank process, and analyzes the thermal and ampacity consequences on the individual lines. This analysis is done in an effort to better define and understand …

Genetic Algorithms In Stochastic Optimization And Applications In Power Electronics, Mengmei Liu

Theses and Dissertations--Electrical and Computer Engineering

Genetic Algorithms (GAs) are widely used in multiple fields, ranging from mathematics, physics, to engineering fields, computational science, bioinformatics, manufacturing, economics, etc. The stochastic optimization problems are important in power electronics and control systems, and most designs require choosing optimum parameters to ensure maximum control effect or minimum noise impact; however, they are difficult to solve using the exhaustive searching method, especially when the search domain conveys a large area or is infinite. Instead, GAs can be applied to solve those problems. And efficient computing budget allocation technique for allocating the samples in GAs is necessary because the real-life problems …

Mathematical Model For Current Transformer Based On Jiles-Atherton Theory And Saturation Detection Method, Xiang Li

Theses and Dissertations--Electrical and Computer Engineering

Current transformer saturation will cause the secondary current distortion. When saturation occurs, the secondary current will not be linearly proportional to the primary current, which may lead to maloperation of protection devices. This thesis researches and tests two detecting methods: Fast Fourier Transform (FFT) and Wavelet Transform based methods. Comparing these two methods, FFT has a better performance in steady state saturation, and Wavelet Transform can determine singularity to provide the moment of distortion.

The Jiles-Atherton (J-A) theory of ferromagnetic hysteresis is one approach used in electromagnetics transient modeling. With decades of development, the J-A model has evolved into different …

Market Based Control Of Pv Inverters In A Distribution System, Kumar Rishikesh

Theses and Dissertations--Electrical and Computer Engineering

A growing energy crisis, a rapid climate change, and a constant depletion of fossil fuel necessitates the role of renewable energy resources like PV (Photovoltaics) and wind energy to form a group of distributed sources of generation. These circumstances promote the use of renewable resources meeting the environmental commitments in terms of checking pollution and toxic footprints. A group of PV and wind energy generation units may work together as micro players to form smart grid systems and participate in an existing distribution system to meet a portion of the daily energy demand. This will help in minimizing the network …