This presentation describes the NASA GRC Multifunctional Materials Team activities in high voltage materials testing capabilities build up and recent research activities

Lizcano, Maricela

Shin, Eugene

Woodworth, Andy

NASA Technical Reports Server

National Aeronautics and Space Administration
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NASA – GRC Materials Research Activities in High 
Voltage High Frequency Power Transmission 
Systems for Electrified Aircraft
Maricela Lizcano1, Eugene Shin2, Andy Woodworth1
1NASA-GRC, 2Ohio Aerospace Institute
IAPG Electrical Systems Working Group Meeting 
March 27-29, 2019 
U.S. Army Research Laboratory South/University of Texas at Austin Commons 
Conference Center Austin, TX 
1
https://ntrs.nasa.gov/search.jsp?R=20190025281 2019-08-31T13:41:33+00:00Z
National Aeronautics and Space Administration
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DC
2
Unique High Voltage Power Transmission Application Light 
Weight High Voltage
Notional Current Technology Description
Combination of power and frequency make this a unique 
application space. Current high voltage cable technology 
is not suitable for high altitude operation.
Turboelectric
2
HV Hybrid Electric Propulsion (HVHEP) Architecture
Future Aircraft will require ~10-20 MW power 
distribution
High Voltage, 3-Phase AC, 
Variable Frequency  400 Hz to 4000 Hz
Vmax = 20 KV Design for V > 41 KV
Aeronautics Research Mission Directorate (ARMD)
Transformative Aeronautics Concepts Program 
Convergent Aeronautic Solutions (CAS) Project 
Transformational Tools and Technology Project
Maricela Lizcano Team Lead
National Aeronautics and Space Administration
www.nasa.gov3
Key Findings: HVHEP Convergent Aeronautics Solutions 
Task
New 
Cable
Materials R&D
New Test Capabilities
Integrated 
Model
Partnerships
Develop 
Standards
• Need New Test Methods and  Component Level Test 
Capabilities 
• Current Test Methods are insufficient
• Altitude/ Environment replication critical
• Materials Development + Modeling Tools 
• Best Design
• Material Technology Development
• Corona resistant materials 
• 2-D  EMI Shielding
• Composite conductors
• Dielectric insulation
• Decrease materials stresses (Thermal, Electrical, 
Mechanical)
• increase performance life
• Foster collaborations with industry and universities
• Industry Provides Integration Paths
• University Led Materials Research
• Develop Testing Standards
Maricela Lizcano Team Lead
National Aeronautics and Space Administration
www.nasa.gov
NASA Glenn Research Center 
Materials and Structures Division
Test Capabilities Build Up
National Aeronautics and Space Administration
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High Voltage Test Capabilities Build-Up
New FY18 TACP/ Transformative Tools and Technology Project Research Area Funded:  
• Build HV Multi-stress Environmental Test Chamber Capability (2-3 Years)
• Demonstrate a 1-5 kV Power Transmission Cable (3-5 Years) 
• Draft Standard Test Method of High Altitude High Voltage Power Transmission Insulation Materials/Cables (5 
years)
Eaton High Voltage Test Setup
• Small sample to component testing
• ASTM testing at RT in oil or air
• 50 Hz and 60 Hz
• AC= 60 KV max   DC 84 KV max
Maricela Lizcano Team Lead 5
GRC Corona Material Evaluation Testbed (CoMET)
• Components up to 40  kV, 2 MHz
• Replicate flight conditions (P, T, RH, vibration etc.) during 
testing 
• Vibration Chamber in Coordination with NASA GRC 
Structure Dynamics Branch
Chamber Build up Status: 
• Site Preparation complete
• All components received except acrylic Chamber and Oscilliscope
• Collaborating with Ohio State University, Dr. Wang (HV power electronics) and Dr. Zhang 
(AC Electric Machines) to help with design and test validation with their High Voltage Lab
Acrylic 
Chamber
mechanical
Vibrations
National Aeronautics and Space Administration
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Pulsed Electro Acoustic Analysis
6
LeCroy Oscilloscope
HP Keyboard and 
Monitor
Pulse GeneratorBarth 50W Impedance
Matching Network
HVDC Power Supply
Electrostatic Voltmeter
AC Power Conditioners (2)
Designed and built by
Lee Pearson
lee.pearson@boxelderinnovations.com
Tony Pearson
tony.pearson@boxelderinnovations.com
Box Elder Innovations, LLC
Corinne, UT  84307
435-744-1014
www.boxelderinnovations.com
Test Fixture
National Aeronautics and Space Administration
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PEA Basic Method Description
7
• DC and pulsed electric fields 
applied across dielectric film
• Charge is induced on each 
electrode
• Waves are generated by each 
charge layer, induced and 
embedded, from electric field 
impulse and contribute to the 
full waveform
• Piezoelectric sensor is 
used to detect the wave 
generated by the electric 
field pulse
– Polyvinylidene Fluoride 
(PVDF) is a plastic 
piezoelectric material
National Aeronautics and Space Administration
www.nasa.gov8
Power Transmission Cable Development Approach
Team Lead: Maricela Lizcano
National Aeronautics and Space Administration
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Status of MMEI Invention
• From systematic parametric analysis, dielectric performance of MMEI was synergistically 
controlled by total overall thickness, individual layer thickness, total accumulated 
thickness of constituent materials, overall thickness ratio of constituent materials, and 
total number of layers or interfaces in addition to bonding integrity. Patent Pending
• Also by dielectric breakdown failure modes.
• Extensive MMEI database 
• 43 different configurations
× GRC in-house test results + 
literature data up to 0.76 mm 
thick
National Aeronautics and Space Administration
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MMEI structures can incorporate 
multifunctionalities by the nature of 
their design capabilities, such as Corona 
PD resistance, moisture barrier, EMI 
shielding, thermal management, and 
mechanical durability, etc. 
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Multilayered structures of well-known 
polymer insulation films, e.g., Kapton PI 
and PFA as bond layer, significantly 
improved dielectric breakdown voltage 
(VB), if well-bonded;
SOA Materials Research
• Kapton PI film alone, 0.38 mm thick, VB=29 kV 
• PFA film alone, 0.38 mm thick, VB = ~27 kVHeat Fuse-Bonding with excellent boding integrity
• Polyimide Sample BS12
• 3-layers
• 0.38 mm thick
• VB=38 kV 
• Polyimide Sample BS22
• 19-layers
• 0.38 mm thick
• VB=46 kV
Micro-Multilayer Multifunctional Electrical Insulation (MMEI) System
Dr. Eugene Shin, Ohio Aerospace Institute, Patent Pending
National Aeronautics and Space Administration
www.nasa.gov
PEA Results on 5 Layered Insulation
14 hr Test at 9 KV
PEA Peak Amplitude vs Time
First Half (7 hr, 9 kV) Second Half (7 hr, 0 kV)
3 Layered Sample
Cross section current density 
mapping over time
National Aeronautics and Space Administration
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PEA Results on 19 Layered Insulation
2 hr Test at 9 KV
1 2 3
PEA Peak Amplitude vs Time
1
2
3
4
4
Peaks are multiple reflected waves or 
waves from polarization charge built 
up between layers, some of which 
are overlapping waves.
No change in peak amplitude was 
seen over time under DC voltage, 
indicating that no sample charging 
occurred.
Charge Density Mapping over time
19 Layered Sample 
has  Vb=46 KV
National Aeronautics and Space Administration
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PEA Results for MMEI 19 Layered Sample
1
2
3
4
2
3 4
1
7 Hours at 8.5 kV 7 Hours at 0 kV
Peak amplitude does not change during test.
Standing waves superposition between layers each 
charge layer generates two layers
Amplitude of all peaks drops to zero in less than 
10 min after voltage shut off. The relaxation time 
of the sample is less than 6 minutes.
National Aeronautics and Space Administration
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Modeling Tool Development
Electromagnetic Model Coupled to Electro-Thermal Model
• Comsol based model accurately reproduces 
frequency skin depth effects
• Current densities
• Frequency dependent resistance 
• Decrease in current (constant voltage) 
with increasing frequency
• Validates the handling of electromagnetic 
fields in the conductors
• Paves the path for 
• Cable loss determination (efficiency of the 
cabling system)
• Hotspot determination (maximum 
operating temperature)
• Aging effects
• Spatial electric field density necessary for 
determining 
• Potential for partial discharge 
• Electrical Insulation requirement     
• Next step is to couple EM model with TE 
model. Expected completion end of Dec 2019.
National Aeronautics and Space Administration
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Commercial Benefit/Applicability of MMEI Structures
HV HP Flat Pod Cable with GORE
• Unique design to carry 0.25 MW at 15 kV (but rated to 40 kV), for -80 °C to >260 °C 
use temperature
• Consisted of six identical conductor pods insulated by the GORE’s proprietary 
PTFE-PTFE composite and arranged horizontally by a corona resistant PTFE jacket
• Efforts to apply MMEI system on the Pod cable using in-house fixture.
Gore Flat Cable Pod       Cross-section GRC In-house cable fixture 
National Aeronautics and Space Administration
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Applicability of MMEI Structures to Bus Bar
HV high frequency bus bar with MERSEN
• A three-phase system for 1 MW up to 10 MW operating power with operating 
voltage of 20 kV ( designed for 40 kV), high frequency (400 Hz up to 4000 Hz), 
and temperature up to 180 °C
• MMEI system to be applied to blank conductors for direct performance 
comparison
National Aeronautics and Space Administration
www.nasa.gov
Power Transmission Take Away 
• High Voltage is the biggest challenge
• Can’t take advantage of large distances and heavy systems (over design) 
other HV systems can use (terrestrial, ships and trains)
• Thermal is a life time limiting issue and will have be dealt  with eventually
• Testing Important:
• Multi scale testing is necessary
• coupon
• component/subsystem
• system 
• Must test like you fly
• multi-stress environment 
• Potential disruptive technology of MMEI system
• Thin, lightweight, and durable structures
• Multifunctional structures including corona resistance, moisture barrier, 
EMI shielding, and thermal management
• Applicable to various full-scale power transmission, e.g., power cable, bus 
bar, inter-connect, etc.
17
National Aeronautics and Space Administration
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Where Do we Go From Here?
Utilizing Machine Learning Concepts
Simple binary compounds can take
extensive time to study. Their behavior in
extreme environments complicates
research and prolongs discovery time. As
a material’s complexity increase so does
the time for discovery. Machine Learning
can utilize NASA’s generational data to
classify trends for prediction and analysis
leading to Rapid Materials Discovery.
Machine Learning (ML) can be used to
approximate lengthy calculations using
training data, significantly reducing time to
get results from demanding
computational quantum and molecular
models. Combined with historical and
current data, an opportunity to find
unknown or overlooked trends increase
significantly. This guides research to Rapid
Materials Discovery.
National Aeronautics and Space Administration
www.nasa.gov
Thank You!
maricela.lizcano@nasa.gov
195/20/2019


NASA - GRC Materials Research Activities in High Voltage High Frequency Power Transmission Systems for Electrified Aircraft

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