Magnetic Materials Enabling Electrified Aircraft Propulsion

Transcription

1 National Aeronautics and Space Administration Magnetic Materials Enabling Electrified Aircraft Propulsion Dr. Cheryl Bowman, Hybrid Gas Electric Propulsion Technical Lead NASA John H. Glenn Research Center Energy Tech 2017 October 31, 2017 Cleveland, OH Advanced Air Transport Technology Project Research Team: Drs. Alex Leary, Ron Noebe and Randy Bowman Vladimir Keylin and Grant Feichter 1

2 Outline How materials research enables electrified aircraft propulsion Definition of magnetic materials How magnetic materials are used in electric machines and electronics Hard/Permanent Magnetic Materials Soft Magnetic Material Application potential for new soft alloy class Manufacturing status and component demonstration status Electrified Propulsion Requires Increase in Performance 2

3 Materials Research Enables Electrified Propulsion Vehicle Concepts Informing Materials R&D: STARC-ABL aircraft concept closes with net fuel burn benefit IF advanced power components can be developed and implemented Other electrified aircraft concepts will require similar improvements Motor/Generator Magnets for Power Density Thermal Management Adv. Manufacturing Insulation Power Electronic Higher Operating Frequencies Lower loss Filtering Higher Efficiency Flight Controls and Mission Profiles HEIST studies Concept NRAs BLI Fans Distortion Tolerant Batteries/Energy Storage Cell Chem for Power Density Pack Eng. for Safety Power Architecture Insulation for HiVolt Better EMI Protection Adv. Conductors Advancement in Component Materials is Required 3

4 Saturation Magnetization (T) Total Field, B Definition of Magnetic Materials All materials have magnetism; Ferromagnetic materials are useful Soft magnets easy domain wall movement with minimal energy tight loop Hard/Permanent magnets more energy required to magnetize and demagnetize but maintain their magnetic alignment H c Coercivity, resistance to de-mag B S Mag Saturation, strength FeNi FeCo Steels Coercivity (A/m) Alnico REPM H c Magnetic Materials are High Performance Alloys B r m i m i Permeability, ease of magnetization External Field Strength, H Chemistry, Grain Size, Domain Size, Crystallographic Orientation are key features Properties can vary with product form Handling can affect properties 4 4

5 Magnetic Materials in Electrical Machines Hard magnets provide constant magnetic field which can greatly improve motor specific power Soft magnets provide magnetic field shaping Rare Earth Permanent Magnets (REPM) are the highest coercivity magnets, so have the highest resistance to demagnetizing fields NdFe class has highest magnetic strength SmCo class has highest temperature resistance FeCo (Hiperco) soft magnetic alloys have the highest saturation strength and are used in applications where mass is critical Other soft magnetic alloys can yield lower losses, especially at high frequency Hard Magnets Provide Constant Magnetic Field 5

6 Soft Magnetic Materials in Electrical Components Soft magnetic materials are the building block of chokes, filter inductors, transformers and EMI shields Transformer Leakage Flux Core Flux Thin laminations reduce eddy current losses Reduced coercivity decreases hysteresis losses Desirable permeability is component dependent; e.g. low permeability for inductors, high permeability for transformers Wide band-gap semi-conductors enable higher power and higher frequency applications Soft magnetic materials must be chosen to compliment the particular power component application Most devices/components benefit from higher operating frequencies, which results in higher power densities (higher output and lower volume) Soft Magnets Enable Power Conversion/Conditioning 6

7 Nanocomposite Alloys Fill Void in Electronics Design Nanocomposite alloys have higher saturation & temperature capability than amorphous alloys and tailorable permeability Classes of Materials Relevant Frequency Range Max Saturation (T) DC Permeability Resistivity (Ω-cm) Useful Temperature Range ( C) Bulk Alloys DC 1 khz x 10-6 <500 Powder Core khz <200 Ferrites 10 khz 100 MHz <300 Amorphous Alloys DC 100 khz x 10-6 <200 Nanocomposites DC 100 khz x 10-6 <400 Frequency up to 100 khz Saturation 2 nd only to bulk alloys Resistivity higher than bulk alloy Temperature 2 nd only to bulk alloys Tunable Permeability controlled by strain or field annealing New Alloy Class with Good Design Characteristics 7

8 Amorphous and Nanocomposite Alloy Production Melt Spinning Fe-base, Co-base or Fe-Ni alloy with glass former creates amorphous alloys that are naturally thin with lower losses at high frequency Selective nanocrystallization of magnetic phases makes a nanocomposite that is still naturally thin with low losses at high frequency as well as Better temperature stability Crystallization in magnetic or strain field allows selective permeability Substantial Soft Magnetic Alloy Development Potential 8

9 B Nanocomposite Alloy Development Finemet is a first generation Fe-based nanocomposite which is commercially available Next generation Fe-based nanocomposite will offer Improved electrical stability such as a more square B-H curve, which allows constant inductance over a wider field Stable permeability also improves performance over a wider range of DC bias conditions Higher temperature stability B S Co-based nanocomposite alloys have better mechanical properties Alloying and processing studies are striving to maximize magnetic properties H c H Fe-Ni alloys are being explored to potentially produce lower cost alloys Substantial Soft Magnetic Alloy Development Potential 9

10 Nanocomposite Alloys Transitioning to Components NASA Glenn operating a medium scale spincaster producing 3 kg of ribbon up to 50 cm wide Producing Fe- and Co-based alloys in quantities and sizes sufficient for relevant-sized components Completed 50-kg delivery of Co-based alloy ribbon for DOE inductor program Casting Co alloy Transitioning Alloys from Lab-scale to Components 10

11 Ready to Design, Build, and Test for Specific Applications Example Nanocomposite has lower losses than a powder core in comparable application COTS powder core: 50 Hz 100 Hz 200 Hz Designed a prototype to replace a ferrite core inductor in a 20 khz NASA controller bench testing shows 40 times lower losses per inductor Working practical fabrication issues associated with manufacturer-ability Substantial Component Development Potential 11

12 Ongoing Partnerships SunShot National Laboratory Multiyear Partnership (SuNLaMP) - Partners included NETL (DOE), NC State, and Carnegie Mellon - Started in March The SunShot program is targeting solar PV cost reduction and new technology development, both of which are required to achieve dramatically increased penetration of solar energy by the year Fort Wayne Metals - Establishing industrial production capabilities for commercialization of these new materials Colorado School of Mines (CSM) - NSF-funded 1 st principle modeling of magnetic materials - Hosted a CSM summer student at GRC Advanced Inductor for DOE Motor Program - Partners included NETL (DOE), Eaton, and Carnegie Mellon - Started in Sept Developing a 3 MW-motor for gas industry applications - Delivered 50 kg of a custom alloy. - Producing test data to support inductor design. Interagency Advanced Power Group (IAPG) - Coordinates research activities across multiple federal agencies - Established an Electrical Materials panel in 2016 under the Electrical Systems Working Group Ohio Federal Research Network - Ohio partners include Case Western and Youngstown State - Developing high-temperature magnetic materials NASA EPSCoR - University of Alabama - Atomistic and micro-magnetic models to guide alloy development efforts Transitioning Alloys from Lab-scale to Components 12

13 Take Away Points Materials Development is important for continued component improvements There is significant development potential remaining in soft magnetic materials which correspond to the significant development potential remaining in power electronics in general Component designers should not limit themselves to off the shelf passive component designs when planning for future power electronic components or systems Electrified Propulsion Requires Increase in Performance 13

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