Christopher Haller
Graduate Research Assistant
Oregon State University
haller@eecs.oregonstate.edu
Hai-Yue Han
Graduate Research Assistant
Oregon State University
haiyuehan@gmail.com
Dr. Ted K.A. Brekken, Ph.D.
Assistant Professor
Oregon State University
brekken@eecs.oregonstate.edu
Dr. Annette von Jouanne, Ph.D. P.E.
Professor
Oregon State University
avj@eecs.oregonstate.com
Research Conducted: June - September 2009
Presentation: October 5, 2009
1.
2.
3.
4.
5.
Wave Energy Background
Design Considerations
Mechanical Layout
Time Domain Electromagnetic Analysis
Conclusion
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11 foot spar
4 foot diameter float
Designed for water depth
of 135 feet
Preparing for sea trial
in Newport
[5]
• 25 feet tall, 11 feet wide
•Direct Drive
Integrated Linear Generator
No pneumatics or hydraulics
• Developed in collaboration
with C.P.T. and the Navy
Wallace Energy Systems and
Renewables Facility
(WESRF)
O.H. Hinsdale Wave Research Lab
(HWRL)
Wallace Energy Systems and
Renewables Facility (WESRF)
•750 KVA Adjustable Power Supply
•Variable Voltage input(0-600Vac), 600A
•3-phase adjustable (while loaded) for
balanced and unbalanced testing
• Highest Power University Lab in the Nation
•Enables Multi-Scale energy research
•Four Quadrant Dynamometer
•Programmable torque/speed
•Dynamic Vector Controls 0-4000 rpm
•Bidirectional Grid Interface
•Regeneration back to the utility grid
• Flexible, 300 hp,Motor/Generator test-bed
• 120KVA programmable source
•Transient VLrms=680V
•Steady State VLrms= 530V
•Frequency range: 45Hz to 2KHz
•10 kW Linear Test Bed
•2 m/s, 10 kN
•1 ms/, 20 kN
•
Wind Energy → 587 W/m2 with 8 m/s mean
distribution of wind speed
•
•
Solar Energy → 200 W/m2 Year Round Average
Wave Energy → 30kW/m Year-Round-Average Available
[2,3,4]
Wave Power Density in Kilowatts per Meter [kW/m]
[1]
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•
•
•
•
Low Speed Operation (5 rpm)
Reciprocating Rotary Design
High Torque Load
Caustic Ocean Environment
Serviceability Complications
Machines Considered
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•
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•
•
PMAC
Doubly Fed Induction
Induction
Reluctance
Vernier Hybrid
Characteristics
•
•
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•
Axial / Radial
Super Conductor
Crescent Shaped
Air / Iron Core
Cross-Sectional Top-Down View
Calculation Methods
•
•
Magnetic Circuit Analysis
Magnetic Shear Line to
2nd Quadrant B-H Operation
intercept
Primary Gene Set
1
Radius of Machine
2
Length of One Side of C-Core
3
Distance Across Air Gap
4
Cross-Sectional Area of Magnets
5
Length of Magnets
6
Thickness of Magnets
7
Wire Turns
8
Wire Gauge
9
Machine Layers
• Initial population created.
• Population doubled.
• Random cross breeding between 1st and 2nd population set
• Random mutations w/ fixed-rate / fixed-probability (quantity)
• All genes saturation checked / adjusted.
• Fitness of chromosomes evaluated, sorted from best to worst.
• Worst ½ of chromosomes discarded, repeat back to doubling.
• Best motor tracked throughout process.
Simplified / Refined Gene Set
1
Magnet Width
2
Magnet Length
3
Magnet Thickness
4
Air Gap Distance
5
Wire Gauge
Simplified GA Variables
1
Magnet Width
2
Magnet Length
3
Magnet Height
4
Air Gap Distance
5
Wire Gauge
•
Maximum allowable turns in
air-gap.
•
Steel thickness based upon
allowed flux density.
•
Many safety/saturation
checks removed.
•
Processing speed 4.3 times
faster than previous model.
{Negative numbers indicate a “more fit” machine}
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•
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-Total Power
-Total Power, -Efficiency, +Steel Volume
-Total Power, -Efficiency, + Total Mass, +AWG, +Wire Turns
-Total Power, Efficiency, +Total Mass, +AWG Size, Wire Turns
Used for final evaluation:
•
-Total Power, -Efficiency, +Total Mass, +Magnet Volume
•
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Swept 25 steps nested sweep.
9,765,625 evaluations.
1.5x the run time of the
refined (2nd) design, 2.8x slower
run time of original design (1st).
•
Evaluated with GA cost
function for fitness.
•
Results different from GA.
Variable
GA
Sweep
Units
1
Magnet Width
.0020
0.0063
[m]
2
Magnet Length
.1157
0.2990
[m]
3
Magnet Height
.0254
0.0244
[m]
.0034
0.0200
[m]
20
19
AWG
4 Air Gap Distance
5
Wire Gauge
Characteristics
GA
Sweep
Units
Open EMF (per coil)
0.258
122
[V]
Current (per coil, @ 2.5 [A / mm2])
1.294
1.632
[A]
Single Layer Total Power
9
1843
[W]
Efficiency (from R. loss)
94
87
[%]
Single Layer Mass
20
811
[kg]
Coil Turns
1
319
qty
Torque (per wheel)
18.5g
4192
[Nm]
Conclusions:
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5 [rpm] generator is feasible.
Generator possible, but heavy.
Weight and slow speed lead to issue of cost.
Future Work Direction:
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Examine larger variety of motor topologies.
Perform more in-depth cost analysis.
Refinements to manufacturability.
[1] http://www.geni.org/globalenergy/library/renewable-energy-resources/ocean.shtml Global
Energy Network Institute
[2] http://blogs.mysanantonio.com/weblogs/clockingin/wind%20turbine.jpg
[3] http://venturebeat.com/wp-content/uploads/2009/07/solar-panel-1.jpg
[4] http://eecs.oregonstate.edu/wesrf/projects/images/Wave%20Energy_Final.ppt
[5] Steven Ernst. Personal interview, 2009. Oregon State University.
[6] Duane C. Hanselman. Brushless Permanent-Magnet Motor Design, 1994.
[7] Magcraft. Permanent magnet selection and design handbook. National Imports,
April 2007.
[8] Ned Mohan. Electric Drives: An Integrative Approach, 2003.
[9] Joseph Prudell. Email, 2009. Oregon State University.
[10]Joseph Prudell. Novel design and implementation of a permanent magnet linear
tubular generator for ocean wave energy conversion, 2007. Thesis for Master of
Science.
[11] P.C. Sen. Principles of Electric Machines and Power Electronics, 1997.
[12] Mueller & McDonald. A Lightweight Low Speed Permanent Magnet Electrical Generator for Direct-Drive Wind Turbines, 2008.