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Power and Energy Institute of Kentucky Faculty Publications

Optimization

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Full-Text Articles in Engineering

Multi-Objective Optimization For Aircraft Power Systems Using A Network Graph Representation, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel Mar 2021

Multi-Objective Optimization For Aircraft Power Systems Using A Network Graph Representation, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Today, the electrification of flight is more popular than ever, creating a wide array of concept aircraft and associated power system topologies. In order to gain insights into benefits of these varying architectures, this paper introduces the development of a framework for electric aircraft power system (EAPS) optimization. The proposed framework accepts inputs from a designer in the form of component parameters and desired flight mission characteristics. A collective graph representing many possible architectures is formed, from which, subgraphs that describe power system topologies meeting the flight requirements are extracted and analyzed. Optimal EAPS architectures with respect to goals of …


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 Oct 2020

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 …


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 Oct 2020

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 …


A Network Graph Technique For The Design Of Electric Aircraft Power Systems, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel Jun 2020

A Network Graph Technique For The Design Of Electric Aircraft Power Systems, Damien Lawhorn, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

Today the electrification of flight is more popular than ever, creating a wide array of concept aircraft and associated power system topologies. In order to gain insights into benefits of these varying architectures, this paper introduces the development of a framework for electric aircraft power system (EAPS) optimization. The proposed framework accepts inputs from a designer in the form of component parameters and desired flight mission characteristics. A collective graph representing many architectures is formed, from which, subgraphs or power system topologies meeting the flight requirements are extracted and analyzed. An optimum topology meeting the flight requirements with minimum mass, …


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 Jan 2020

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 …


Optimal Combinations Of Utility Level Renewable Generators For A Net Zero Energy Microgrid Considering Different Utility Charge Rates, Evan S. Jones, Huangjie Gong, Dan M. Ionel Nov 2019

Optimal Combinations Of Utility Level Renewable Generators For A Net Zero Energy Microgrid Considering Different Utility Charge Rates, Evan S. Jones, Huangjie Gong, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

High initial investment and the intermittent nature of resources are major challenges for large scale renewable generation. The size of photovoltaic (PV) and wind turbine (WT) farms in the microgrid needs optimized to avoid curtailment and to efficiently meet the demand of a power system. Battery energy storage systems (BESSs) may also be used to improve flexibility. This paper explores the optimal sizing for PV and wind generators, as well as a BESS at the utility level for a large grid-connected net zero energy (NZE) hybrid microgrid considering characteristics such as initial investment, levelized cost of energy (LCOE), operating costs, …


Waved: A Coreless Axial Flux Pm Motor For Drive Systems With Constant Power Operation, Narges Taran, Vandana Rallabandi, Dan M. Ionel Jun 2019

Waved: A Coreless Axial Flux Pm Motor For Drive Systems With Constant Power Operation, Narges Taran, Vandana Rallabandi, Dan M. Ionel

Power and Energy Institute of Kentucky Faculty Publications

In this paper, a two-phase coreless AFPM machine with wave winding, 2-stators, and 3-rotors for traction applications is studied. A highly general optimization method, employing 3D FEA as the computational engine is employed. Number of poles in addition to other geometrical variables are included as independent optimization variables. A method for extending the speed range by rotating one of the stator discs with respect to the other at constant power operation is proposed. An inverter configuration including Si and wide band gap devices is proposed to be employed in conjunction with the machine under study. The study includes a comparison …


Design Optimization Of Electric Machines With 3d Fea And A New Hybrid Doe-De Numerical Algorithm, Narges Taran, Vandana Rallabandi, Dan M. Ionel, Greg Heins, Dean Patterson, Ping Zhou May 2019

Design Optimization Of Electric Machines With 3d Fea And A New Hybrid Doe-De Numerical Algorithm, Narges Taran, Vandana Rallabandi, Dan M. Ionel, Greg Heins, Dean Patterson, Ping Zhou

Power and Energy Institute of Kentucky Faculty Publications

This paper discusses the multi-objective optimization of axial flux permanent magnet (AFPM) machines with ferrite spoke-type magnets, utilizing 3D finite element models. Three-dimensional finite element analysis is computationally expensive, and furthermore, substantial computation time is expended by optimization algorithms in evaluating low performing designs whose performance is far from the optimum if the search space is not specified correctly. In this regard, this work proposes two new methods for identifying the search space. The search is limited to ranges of input geometric variables where high performing designs are likely to be found. The optimization algorithm utilized is based on surrogate …


Two-Level Surrogate-Assisted Differential Evolution Multi-Objective Optimization Of Electric Machines Using 3-D Fea, Narges Taran, Dan M. Ionel, David G. Dorrell Nov 2018

Two-Level Surrogate-Assisted Differential Evolution Multi-Objective Optimization Of Electric Machines Using 3-D Fea, Narges Taran, Dan M. Ionel, David G. Dorrell

Power and Energy Institute of Kentucky Faculty Publications

A two-level surrogate-assisted optimization algorithm is proposed for electric machine design using 3-D finite-element analysis (FEA). The algorithm achieves the optima with much fewer FEA evaluations than conventional methods. It is composed of interior and exterior levels. The exploration is performed mainly in the interior level, which evaluates hundreds of designs employing affordable kriging models. Then, the most promising designs are evaluated in the exterior loop with expensive 3-D FEA models. The sample pool is constructed in a self-adjustable and dynamic way. A hybrid stopping criterion is used to avoid unnecessary expensive function evaluations.


Exploring The Efficiency And Cost Limits Of Fractional Hp Axial Flux Pm Machine Designs, Narges Taran, Vandana Rallabandi, Greg Heins, Dan M. Ionel Sep 2018

Exploring The Efficiency And Cost Limits Of Fractional Hp Axial Flux Pm Machine Designs, 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 flux paths in axial flux PM (AFPM) machines necessitate the use of computationally expensive 3D 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 FEA evaluations. The proposed algorithm is employed to optimally design an AFPM machine within a specified envelope, …