OUTLINE

Lecture 1 – Case for Electrifying Large Electric Aircraft (Dyson)

o This module details the benefits of electrified propulsion for large aircraft

o Trade studies and analyses of several concept vehicles are summarized

o A first-order breakeven analysis that reveals the electrical power system requirements that enable several electrified aircraft propulsion architectures is presented

o A framework for comparing electric drive system performance factors, such as electrical efficiency, in the context of electrified and traditional propulsion systems is provided

o Expectations for electrical system component requirements is provided, setting the stage for the component focused modules

Lecture 2 - Performance Assessment of Hybrid Electric Aircraft (Gladin)

o This module covers how to assess whether new powertrain architecture can “buy its way” onto an aircraft, and when, specifically, the architecture becomes physically and economically viable.

o Assessment Process: Introduction and steps in the process

o Baselining: Projecting the baseline forward, defining EIS and technology level (TRL considerations), defining propulsion technologies

o Defining the EP concept: Schematics/Representations, EP architecture conceptualization and review of basic trades, morphological matrices, defining a CONOPS – Examples, electric technology infusion

o Propulsion system modeling and representation: Schematics, review of components, Standard performance parameters and definitions, units, nomenclature, etc.

o Vehicle modeling and representation: Standard parameters to declare, Mission(s): Flight segments, Power management, Guidelines for presentation of results

o Calculating metrics: Energy specific air range, Fuel burn, Energy, ICAO CO2, Life-cycle CO2, TOFL, energy, DOC, NOx, etc.

o Example Assessment Results

Lecture 3 – Electric Power System and Protection (Bayles)

o This module will describe the detailed considerations related to the design of safe, reliable, interconnected electrical power system in the aircraft

o It will introduce the basic features of the electric power system and summarize its design as well as its control, and protection functions.

o Implications of the expected increase in power levels (of generation, distribution, and loads) required for the electrification of propulsion systems will be examined.

o An overview of power quality requirements is provided.

o Key components of the electric power system and their functions are described to prepare for the discussions of individual system components that follow in subsequent modules.

Lecture 4 – Conventional Electric Machines (Xiaolong Zhang)

o A comprehensive overview of conventional large electrical machines for electrified aircraft applications is presented in this module.

o Major design challenges associated with high specific power MW-scale machines are identified, and approaches for mass reduction and specific power improvement are described.

o A review of EAP powertrain architectures and how high specific power electric machines enable them is provided.

o A description of motor and generator systems, with a focus on propulsion motors, high speed generators, and system considerations unique to the EAP powertrain is provided.

o Design principles for high power, lightweight, MW-scale EM development are discussed.

o A comprehensive survey of over 50 SOTA HSP machines is presented and common features of HSP machines are identified and promising options for further weight reduction are discussed.

Lecture 5 – Superconducting Machines (Haran)

o This module covers superconducting technology which enables elimination of Ohmic losses at cryogenic temperatures, significant increases in power density.

o The physics of superconductivity is introduced and the important considerations relevant to superconducting machine design for electrified aircraft propulsion is covered.

o Various superconducting machine topologies being pursued by different research groups are described, including the current state-of-the-art.

o A detailed assessment of specific challenges related to electrified aircraft applications – ‘ac’ losses in the superconducting coils and the need for compact cryocoolers – is provided.

o The physics and advantages of superconducting cables are also presented, along with a look at future superconducting technology trends

Lecture 6 – Conventional Power Electronics (Wheeler)

o This module introduces general power conversion concepts while fostering a solid high-level understanding of power electronic converter topologies.

o Topologies and devices that are crucial for electrified aircraft propulsion will be described.

o Power system metrics, including power density and voltage, and integration techniques are presented.

o A description of relevant power converter topologies, including two- and multi-level inverters, direct and indirect matrix converters, rectifiers is provided.

o Power converter topologies for open winding and multi-phase electric machines, and fault-tolerant topologies will also be described.

o The module concludes with a discussion on emerging semiconductor devices and materials, including a discussion and comparison with silicon-carbide (SiC) device options.

Lecture 7 – Cryogenic Power Electronics (Zhang)

o This module introduces cryogenic power electronics that can enable the highly efficient ultra-dense power conversion systems which are critical for EAP.

o Several key steps in the development of cryogenic power electronics, from the component up to the converter level is presented.

o The characterization of critical components – including power devices and magnetics – at cryogenic temperature is introduced to establish the basic knowledge necessary for cryogenic design and optimization.

o Special considerations specific to cryogenic design, and trade and design studies for the cryogenic power stage and filter electronics are detailed.

o An example of a high- power cryogenically-cooled inverter system for an EAP application is illustrated, with safety considerations and the protection scheme highlighted.

Lecture 8 – Electrochemical Energy Storage and Conversion for Electric Aircraft (Misra)

o This module provides an overview of electrochemical energy storage and conversion systems for electrified aircraft propulsion.

o An overview of the state-of-the-art in battery technology and of the various EAP concepts and missions it enables is provided.

o A review of battery technology requirements for various classes of electrified aircraft and EAP concepts.

o Recent battery technology advances and their applicability and limitations for expanding the electrified aircraft market.

o Application of fuel cells, flow batteries, and supercapacitors for electrified aircraft.

o A review of multifunctional structures with energy storage capability and their potential application to EAP.

Lecture 9 - Thermal Management System (Lents)

o This module details aerospace thermal management system approaches and the unique challenges of managing electric drivetrain waste heat across the wide variety of electrified aircraft propulsion architectures.

o Thermal management system component design and performance

§ Heat acquisition – component temperature limits; cooling technologies and approaches for moving heat from component source load to the cooling medium; also includes heat pumping systems for moving heat from a heat source at lower temperature than the heat sink

§ Heat transport – guidelines for estimating weight and power consumption of pumps, fans, ducts, and pipes

§ Heat rejection – methods for sizing heat exchangers, phase change materials, and skin coolers

o Methods for estimating the impact of TMS weight, power consumption and induced ram drag on aircraft performance

o Example thermal management system implementations

o Full system model examples to introduce general analysis concepts and heat transport and rejection components, including the underlying physics-based equations necessary for their analysis.

o The detailed step-by-step design of a reference TMS, listing constraints, imposed conditions, methods for estimating free parameters, calculated values, and design trade considerations.

INSTRUCTORS

Mr. Bob Bayles is Senior Fellow Engineer- Systems at Collins Aerospace. He has been part of the Collins Electric Power Systems business for 40 years and is involved with many of the innovations associated with development of generation, conversion, and distribution of electrical power systems on multiple aircraft platforms. Currently Bob is leading the high power / electric & hybrid electric propulsion technology roadmap for Raytheon Technologies. Bob holds a Bachelors and Master’s degree in electrical engineering, and a Master’s degree in business administration. He holds 4 U.S. patents.

Dr. Rodger Dyson has worked at NASA Glenn Research Center for over 30 years in Power, Propulsion, and Thermal Technologies supporting both aeronautics and space missions. He currently serves as the hybrid gas electric propulsion technical lead, NASA electric aircraft testbed principal investigator, NATO hybrid electric aircraft technology domain lead, founded the Power and Propulsion Systems Alliance hybrid electric technical area team, and leading a new thermal energy conversion initiative to recycle heat on aircraft. He is also a prolific inventor with 8 licensed patents, founder of two technology startup companies, and recently served as Chief Technology Officer at Nirvana Energy Systems.

Dr. Jonathan Gladin is a research engineer at the Aerospace Systems Design Lab at Georgia Tech where he performs research in the area of propulsion for aircraft applications, specifically for hybrid electric propulsion systems and also in the areas of propulsion/airframe integration. He has contributed to four different NASA sponsored NRA’s in the area of hybrid electric propulsion and has many technical publications in that area. He is the lead developer of Georgia Tech’s hybrid electric modeling environment, GT-HEAT, and is actively involved in teaching students the fundamentals of hybrid electric aircraft for research applications. He also has technical experience in the areas of boundary layer ingestion systems, aircraft sub-systems, and thermal management. He received his undergraduate degree in Aerospace Engineering from the Georgia Institute of Technology in 2006 and worked as a structural analyst for Sikorsky Helicopters for three years on the Black Hawk program before returning to Georgia Tech to pursue his graduate studies in 2009. He received his Master’s degree in Aerospace Engineering in 2011 and Ph.D. in 2015.

Dr. Kiruba Haran is a professor in the department of Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign. He has over twenty years of experience in electric machinery, including 13 years at GE where he led the research group focused on electric machines and drives technology. Kiruba is a member of the steering committee of the IEEE Transportation Electrification Community, the IEEE Council on Superconductivity, and the AIAA Aircraft Electric Power & Propulsion Working Group. He is an IEEE Fellow, cited for contributions to advanced electrical machines for aerospace and renewable energy applications. Kiruba received his PhD in Electric Power Engineering from the Rensselaer Polytechnic Institute in 2000.

Mr. Charles Lents, Associate Director at the Raytheon Technologies Research Center, has thirty years of experience in the conceptual design of integrated aircraft primary and secondary power and thermal management systems. At RTRC, Chuck led a team in the development of an integrated modeling environment for the study of integrated total aircraft power systems and their impact on air vehicle performance. He has led several studies investigating power and thermal management solutions for a range of commercial and military vehicles Currently, he is leading RTRCs electrified propulsion research agenda. Chuck received his B.S.M.E from the University of Illinois in 1982 and his M.S.M.E. from Purdue University in 1984.

Dr. Ajay Misra serves as the deputy director of Research and Engineering at NASA’s John H. Glenn Research Center (GRC) in Cleveland. He shares responsibility with the director of Research and Engineering for leading and managing approximately 1,100 scientists, engineers and administrative staff dedicated to Glenn’s research and development in propulsion, communications, power, and materials and structures for extreme environments in support of NASA’s aeronautics and space missions. Prior to his current role, Dr. Misra served as chief of the Materials and Structures Division in the Research and Engineering Directorate at Glenn, where he provided executive leadership for all aspects of planning, organizing and directing technology development and demonstration efforts, ranging from basic and applied research in advanced materials and structures for aerospace propulsion and power to the development of space flight structures. Dr. Misra has been actively engaged for the last several years in the development of electric aircraft technologies at the GRC. He champions all battery research at the Center related to the electric aircraft. In the past two years, he organized two electric aircraft battery workshops that identified the battery needs and challenges for electric aviation. Dr. Misra earned a doctorate degree in materials science and engineering from the University of California, Berkeley and a master’s degree in business administration from Cleveland State University. He has published more than sixty papers and four book chapters. He has made many invited and keynote presentations at various national and international electric aircraft conferences. Dr. Misra has received several prestigious awards for his work at NASA, including the Presidential Rank Award for Meritorious Executives in 2015.

Prof Pat Wheeler received his BEng [Hons] degree in 1990 from the University of Bristol, UK. He received his PhD degree in Electrical Engineering for his work on Matrix Converters from the University of Bristol, UK in 1994. In 1993 he moved to the University of Nottingham and worked as a research assistant in the Department of Electrical and Electronic Engineering. In 1996 he became a Lecturer in the Power Electronics, Machines and Control Group at the University of Nottingham, UK. Since January 2008 he has been a Full Professor in the same research group. He was Head of the Department of Electrical and Electronic Engineering at the University of Nottingham from 2015 to 2018. He is currently the Head of the Power Electronics, Machines and Control Research Group, Global Director of the University of Nottingham’s Institute of Aerospace Technology and is the Li Dak Sum Chair Professor in Electrical and Aerospace Engineering. He is a member of the IEEE PELs AdCom and was an IEEE PELs Distinguished Lecturer from 2013 to 2017. He has published 500 academic publications in leading international conferences and journals.

Dr. Zheyu Zhang is the Warren H. Owen – Duke Energy Assistant Professor of Engineering at Clemson University. He was a Research Assistant Professor in the Department of Electrical Engineering and Computer Science at the University of Tennessee, Knoxville from 2015 to 2018. In 2018, he joined General Electric Research as a Lead Power Electronics Engineer at Niskayuna, NY, USA. Dr. Zhang has over 10 years of professional experience with balanced industry and academic career in the area of power electronics for electric propulsion, electrified transportation, renewables, energy storage, and grid applications. His research interests include wide band-gap based power electronics, modularity and scalability technology, medium voltage power electronics, advanced manufacturing and cooling technology (e.g. cryogenic cooling) applied in power electronics, and highly efficient, ultra-dense, cost-effective power conversion systems for electric propulsion, electrified transportation, renewables, energy storage, and grid applications. Dr. Zhang is currently an Associate Editor for IEEE Transactions on Power Electronics and IEEE Transactions on Industry Applications. He is a senior member of IEEE.

Mr. Xiaolong Zhang received his Bachelor’s and Master’s degrees in electrical engineering from the Huazhong University of Science and Technology (HUST), China, in 2011 and 2014, respectively. He is currently working towards his Ph.D. degree in electrical engineering at the University of Illinois, Urbana-Champaign. From August 2014 to July 2015, he was working as a research engineer in the Nanyang Technological University (NTU), Singapore. His research interests are on the design and optimization of electrical machines used in emerging fields, e.g. renewable energy and electrified vehicles, etc.

Classroom hours / CEUs: Receive an AIAA Certificate of Completion and 18 Hours CEU/PDH Credit!