Flywheel Storage for Lunar Colonization
University of Idaho Department of Electrical and Computer Engineering
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Purpose Statement
To establish the scientific and technical merit, and feasibility, of using flywheel energy storage systems in support of human colonization and exploration of the lunar surface
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Flywheel Storage for Lunar Colonization
• Machine Topology Evaluation• Power Electronics and Control• Construction of Test Apparatus
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Flywheel Storage for Lunar Colonization
Machine Topology EvaluationIan Higginson
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Research Objectives• Evaluate technical merit and feasibility
of:
Electrical energy transfer machinery that minimizes iron idling losses
Extreme temperature electronics to manage energy transfer and storage
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1. No slip rings/commutators2. Significant idling iron loss reduction3. Low volume
High torque per volume High torque per mass
Flywheel Criteria
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• Synchronous Reluctance• Field Regulated Reluctance• Iron-on-rotor PM;
Ironless statorIron rotor
• Ironless PM (Halbach array)
Machine Topologies
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Torque per Unit Volume• Synchronous Reluctance: 34.16
kNm/m3
• Field Regulated: 35.52 kNm/m3
• Iron-on-rotor PM: 27.18 kNm/m3
• Ironless PM: 25.33 kNm/m3
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• Prepare Phase 2 Proposal• Formalize force density equations• Verify analytical data• Prototype low idle iron loss machine• Develop equations for torque per unit
mass
Goals
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Power Electronics for Lunar Flywheels
Power Electronics and ControlChristopher Douglas
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Research Objectives• Evaluate technical merit and
feasibility of:
Electrical energy transfer machinery that minimizes iron idling losses
Extreme temperature electronics to manage energy transfer and storage
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• Operate over extreme temperature range
• Reduce excess mass• Increase energy/power density• Develop control method for flywheel
Purposes
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• Extreme thermal & radiation environment Phase I involves thermal problems -190C to +125C 336 hours of Lunar night/day Radiation exposure
• Heat transfer mechanisms Conduction Radiation
Lunar Environment
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Semiconductor Technologies• Silicon on Insulator
Commercial Ratings HTANFET• 90V, 1A• Rated -55C to +225C
Cycle Testing -195C to +85C• Silicon Germanium HBT – Research
Data 50V, 2A Cycle Testing -195C to 25C Cycle Testing 25C to 300C 14
Application
• Heated or cooled enclosure Added mass Lost energy
• Temperature division multiplexing (TDM) Range dependent
electronics Strategic layout of
electronics• Stacked MOSFET
topology15
Deflux Control
• Rotor defluxing method Decaying sinusoidal current (θr)
• Parameters Decay rates Frequency of defluxing current
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Defluxing - Stator
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Future Goals• Prepare phase II proposal• Acquire models for power
electronics• Develop control system for lab
prototype• Deflux spinning rotor• Investigate:
Temperature division multiplexingStacked MOSFET topologyHeat transfer in vacuum
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The University of Idaho
Construction of Test ApparatusTimothy Hildebrandt, Bryan Hyde,
Josh Ulrich, Kord Hubbard
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Synchronous Reluctance Machine• Purchase Machine
High Quality Bearings Controlled Environment
• Characterize Losses Low Friction Machine
• Power Electronics Lunar Environment Adaptability to Machine
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Power Loss Characterization• Present:
Armature resistance Brush drop losses Interpole winding resistance
• Future: Iron losses• Difficult to measure
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Preliminary Iron Losses• Constant Speed• Vary Gen. Field Current
0 1.667 3.333 5 6.667 8.333 10236
236.5
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237.5
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238.5
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239.5
240Iron Losses in Synchronous Generator
Field Current (Aac)
Pow
er L
oss (
W)
PFEloss
IfAC
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Power Inverter • Used for defluxing
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Future Goals• Prepare for Phase II Proposal• Purchase/Characterize machine• Develop testing strategy• Measure iron losses accurately• Define lunar power requirements
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• April – Sep.: Prepare Phase 2 Proposal• April 30th: Formalize force density equations• May 1st: Begin verification of analytical data• May 15th: Parameterize defluxing method• May – Aug: Investigate TDM scheme• June 1st: Construct flywheel prototype
2010 Timeline for Future Work
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• June: Construct prototype electronics system
• June – July: Develop testing strategies• June – Aug: Collect data at Boeing• June – Aug: Characterize machine• June – Sept: Investigate switch device
models• June – Aug: Develop torque per mass
eq’s.
2010 Timeline for Future Work
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2010 Timeline for Future Work
• Aug: Prepare testing environment• Aug: Design of power electronic
system• Aug – Sept: Document results• Sept: Submit Phase 2 Proposal• Sept: Measure losses accurately
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The University of Idaho
Discussion
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