1
HydroFly: Flywheel
Gavin AboNate StoutNathan Thomas
Background
•The flywheel is a mechanical energy storage device
–Once up to speed very little energy is required to
maintain desired speed
•Small draw on AMPS
Background Continued
• Flywheels were used during the industrial revolution to smooth out
torque pulses in mechanical systems
– We will use it in a similar fashion to smooth out voltage sags on
the AMPS
Voltage Sags• Drop in RMS voltage
– Typically last from 1/2 cycle to a minute
– Caused by actions on the system that have large current draws
• Motors starting
• Transformers energizing
• Pulsed load switching
• Electrical faults
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Why Sags Are Bad
• Voltage sags have adverse affects on sensitive loads
– Sags can cause loads to shutdown
• Loss of use
• Loss of Data
• Loss of production time
Navy
• Survivability of Naval ships in battle situations
– In battle situations voltage sags can occur due
to various reasons, causing critical systems to
go offline
• Flywheel voltage sag detection devices could be used to help
protect these critical systems
Education
• The flywheel energy storage system may be implemented into future
power classes at the University of Idaho for educational purposes
– Power quality classes
– System protection classes
– Transient analysis classes
Main Objective
• Implement the design by Satish Samineni– Be able to correct for up to 33% voltage sags
on AMPS
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• We will focus on– Induction motor controller– Programming of the DC link– Synchronizing to AMPS– Protection circuitry
• We will not do:– Design of DC link– Design of Induction motor controller
Block Diagram
Switching PWM• A triangle wave reference is
applied to a signal
– Compared
– Triangle high: logic 0
– Signal high: logic 1
– Applied to all 3 phases
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Block Diagram Series Transformer Diagram
Flywheel energy
A
CB
storage system
Synchronization & Protection• Use a phase lock loop to monitor and regulate phase• Add any additional protection needed xθ( ) 2sinθ( ):= yθ( ) sinθ( ):= zθ( ) xθ( ) yθ( )+:=
10 5 0 5 104
3
2
1
0
1
2
3
4
xθ( )
yθ( )
zθ( )
θ
In phase Out of phase
a θ( ) xθ 75deg⋅+( ) y θ( )+:=
10 5 0 5 104
3
2
1
0
1
2
3
4
xθ 75deg⋅+( )
y θ( )
a θ( )
θ θ, θ,
5
BudgetFlywheel Budget
Item PriceInduction Motor Controller $350DC link $4,0003-phase transformer (500VA) $125Design Poster/Report Binding* $15Project Display Costs* $35Miscellaneous $300
Total $4,825
*Shared costs between the two groups
Time Schedule
1/31/2005
2/28/2005
3/28/2005
4/25/2005
5/23/2005
6/20/2005
7/18/2005
8/15/2005
9/12/2005
10/10/2005
11/7/2005
12/5/2005
1/2/2006
Initial Design for Prototypes
Project Brief ings (w eekly - Semester 1)
Ordering Voltage Inverters and Buck Converter
Design Review
Interface Components to Fuel Cell
Implement simulation for Flyw heel System
Demonstrate Working Prototype
Project Report and Notebook Due (Semester 1)
Summer Break
Project Brief ings (w eekly - Semester 2)
Interface Fuel Cell Components to AMPS
Interface Components to Flyw heel
Revise Voltage Control System
Interface Flyw heel to AMPS
Finalize Protection Circuitry
Complete/Debug Interfacing to AMPS
Final Product Demonstration/Release/Final Report
Questions?
www.ece.uidaho.edu/hydrofly