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11. Design Optimization of a Direct-Drive Wind Generator With a Reluctance Rotor and a Flux Intensifying Stator Using Different PM Types

Author

Mohammadi, Ali, Badewa, Oluwaseun A., Chulaee, Yaser, Lewis, Donovin D., Essakiappan, Somasundaram, Manjrekar, Madhav D., and Ionel, Dan M.

Abstract

This paper presents a large-scale multi-objective design optimization for a direct-drive wind turbine generator concept that is based upon an experimentally validated computational model for a small-scale prototype motor of the same type. By integrating an outer reluctance-type rotor and a segmented stator with toroidally wound single-coil modules containing spoke-type PMs, the design optimization aims to minimize losses, active mass, and torque ripple while adhering to a power factor constraint. The AC windings and PMs are positioned in the stator and this concept enhances flux concentration, enabling the use of more affordable high energy non-rare-earth (special type) magnets. The exterior rotor follows a simplified reluctance-type configuration, eliminating active electromagnetic components. The operational principle, described in detail, guides design studies using electromagnetic 2D finite element analysis (FEA), showcasing the potential of this configuration to match rare-earth PM performance, with special type PMs, thus addressing cost and supply challenges. Furthermore, alternative materials including the substitution of aluminum wire for copper wire, have also been investigated in this study. The proposed multi-objective design optimization uses the response surface method (RSM) to initiate the optimization and the results on a 3MW, 15 rpm generator, highlight the benefits of this topology, achieving competitive metrics like goodness, specific thrust, and efficiency without rare-earth permanent magnets.

Published
2024
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28. Electric Water Heater Modeling for Large-Scale Distribution Power Systems Studies with Energy Storage CTA-2045 Based VPP and CVR.

Author

Alden, Rosemary E., Gong, Huangjie, Rooney, Tim, Branecky, Brian, and Ionel, Dan M.

Subjects
WATER heaters, ENERGY storage, POWER resources, ENERGY management, WATER temperature, THERMAL comfort
Abstract

As the smart grid involves more new technologies such as electric vehicles (EVs) and distributed energy resources (DERs), more attention is needed in research to general energy storage (GES) based energy management systems (EMS) that account for all possible load shifting and control strategies, specifically with major appliances that are projected to continue electrification such as the electric water heater (EWH). In this work, a methodology for a modified single-node model of a resistive EWH is proposed with improved internal tank temperature for user comfort modeling and capabilities for conservation voltage reduction (CVR) simulations as well as Energy Star and Consumer Technology Association communications protocol (CTA-2045) compliant controls, including energy storage calculations for "energy take". Daily and weekly simulations are performed on a representative IEEE test feeder distribution system with experimental load and hot water draw (HWD) profiles to consider user comfort. Sequential controls are developed to reduce power spikes from controls and lead to peak shavings. It is found that EWHs are suitable for virtual power plant (VPP) operation with sustainable tank temperatures, i.e., average water temperature is maintained at set-point or above at the end of the control period while shifting up to 78% of EWH energy out of shed windows per day and 75% over a week, which amounts to up to 23% of the total load shifted on the example power system. While CVR simulations reduced the peak power of individual EWHs, the aggregation effect at the distribution level negates this reduction in power for the community. The EWH is shown as an energy constant load without consistent benefit from CVR across the example community with low energy reductions of less than 0.1% and, in some cases, increased daily energy by 0.18%. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Co-Simulation of Electric Power Distribution Systems and Buildings including Ultra-Fast HVAC Models and Optimal DER Control.

Author

Jones, Evan S., Alden, Rosemary E., Gong, Huangjie, and Ionel, Dan M.

Abstract

Smart homes and virtual power plant (VPP) controls are growing fields of research with potential for improved electric power grid operation. A novel testbed for the co-simulation of electric power distribution systems and distributed energy resources (DERs) is employed to evaluate VPP scenarios and propose an optimization procedure. DERs of specific interest include behind-the-meter (BTM) solar photovoltaic (PV) systems as well as heating, ventilation, and air-conditioning (HVAC) systems. The simulation of HVAC systems is enabled by a machine learning procedure that produces ultra-fast models for electric power and indoor temperature of associated buildings that are up to 133 times faster than typical white-box implementations. Hundreds of these models, each with different properties, are randomly populated into a modified IEEE 123-bus test system to represent a typical U.S. community. Advanced VPP controls are developed based on the Consumer Technology Association (CTA) 2045 standard to leverage HVAC systems as generalized energy storage (GES) such that BTM solar PV is better utilized locally and occurrences of distribution system power peaks are reduced, while also maintaining occupant thermal comfort. An optimization is performed to determine the best control settings for targeted peak power and total daily energy increase minimization with example peak load reductions of 25+%. [ABSTRACT FROM AUTHOR]

Published
2023
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45. The Efficiency and Degree of Penetrability of Frequent Washing Solutions Used in Endodontal Treatment

Author

Mihaela Salceanu, Cristina Stefanescu, Diana Maria Anton, Ionel Dan-Cristian, Cristina Iordache, Alexandru Andrei Iliescu, Gabriela Popa, Marius Manole, and Anca Melian

Subjects
Process equipment, business.industry, Materials Science (miscellaneous), Process Chemistry and Technology, General Engineering, General Chemistry, General Medicine, General Biochemistry, Genetics and Molecular Biology, Degree (temperature), Petrochemistry, Materials Chemistry, Medicine, General Pharmacology, Toxicology and Pharmaceutics, Process engineering, business
Abstract

The new directions of contemporary endodontics to the evolution of treatment techniques are: CTCB, digital radiography, operating microscope, apex locators, titanium nickel rotation tools and rotating systems that allow them to be used, special endodontic irrigation means, use of ultrasonic means, laser applications. The success rate of nowadays endodontic treatments based on the principles accepted and adopted so far should be rather high. However, there are studies that indicate a fairly low percentage of fully successful endodontic treatments. The main causes for which these data are recorded are various, some are strictly the dentist�s technique and some are related to the patient�s field. Obviously, there is a contradiction between what can be achieved and the final result. The study includes a batch of 52 teeth pluriradicular as well as monoradiculars considered irrecoverable and extracted due to clinical situations requiring this method of treatment. Anatomy of dental canals is an important factor to be considered in the irrigation efficiency of the apical region; the degree of permeability of dentinal canals in this area is poor due to very small diameters, cumulative factors can lead for sure to a failure of endodontic treatment. In the coronal and media regions of the channels, the effectiveness of the lavage solutions used could be assessed. These very good results were in accordance with the studies performed and presented.

Published
2019

46. CONSIDERATION REGARDING THE ROLE OF GEOPOLITICAL PIVOT OF THE BLACK SEA

Author

GLODARENCO Olimpiu Manuel and CIOCOIU Ionel Dan

Subjects
still conflicts, secessionist conflicts, cooperation, interference, security, Architectural engineering. Structural engineering of buildings, TH845-895, Engineering design, TA174
Abstract

Influenced by political and military events, the Black Sea has become transformed into a complicated intersection of geopolitical and geo-economic boundaries, becoming also a framework within which the Euro-Atlantic community asserts itself. It's strategic importance lay mostly in the role it played as a bridge and a frontier, a buffer and transit zone, between Europe and Asia at the crossroads between powers and empires. Black Sea has remained during its history a sensitive spot on the larger Eurasian map, an area in which the Great Powers employed their geostrategic concepts about the control of the seas.

Published
2014

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