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Electric Propulsion Subsystem for a
Parallel-Drive, Formula Hybrid Vehicle
Brett Bashford
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Formula Hybrid Vehicle
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Vandal Hybrid Racing
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Overview of team
• ME and EE Advisors
• Grad students
– ME, EE, CompE
• Senior Design
• SAE club
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Presentation Outline
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About the Competition
Competition Events
Goals for the electric propulsion sub-system
Electric propulsion and monitoring equipment
Testing
Data and Control
Final Thoughts
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About the Competition and Goals
• New Hampshire Motor Speedway, Loudon, NH
• April 30th to May 3rd, 2012
• Engage students in sustainable transportation
technology
• Create knowledge base for future design
teams
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Static Events
• Technical Inspection
– Not worth any points but must pass
• Marketing Presentation
– 100 points
– Sell the car
• Design
– 200 points
– Review engineering considerations
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Dynamic Events
• Acceleration
– 150 points
– 75m drag
• Autocross
– 150 points
• Endurance
– 400 points
– 22km
– 19.5MJ
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Picture of Endurance Track
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Why electrical?
97.00
Stock YZ250F and FHSAE EFI
Tuned YZ250F
87.00
Torque (ft-lbs)
77.00
Va
e_mtr e_shaft
e_shaft
67.00
57.00
FHSAE
Stock
47.00
37.00
e_shaft
rpm
27.00
17.00
7.00
500.00
1000.00 1500.00 2000.00 2500.00 3000.00
Speed of Counter Shaft (RPM)
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My role
• Provide propulsion system
– Primary objective is 75m, electric only drag
– Lightweight
• Pass electrical technical inspections
• Low risk
• Communicate the basics
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System Functions
• Energy storage
• Energy conversion from electrical to
mechanical
• User interface
• Sensing
• Energy management
• Safety
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Physical Layout of components
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High voltage diagram
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Propulsion Components
• DC Motor
– Peak current of 400A
– Peak power of 34.32kW (46hp)
• DC/DC Converter
– Speed and torque control available
– Over current protection
– Four quadrant operation
– Simple LED fault code and GUI
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Propulsion Components (cont.)
• Lithium Iron Batteries
– 3.2V/cell, 40Ah
– Peak current of 400A
– Good power density
– Lithium balancing
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Safety Monitoring
• Battery management system
– Monitors temperature
– Monitor and equalize individual cell voltage
• Ground Fault Monitor
– Checking for connection
between HV system and chassis
– Trips in about ten seconds for
less than 100kohm fault
resistance
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Battery Lab Safety
• Eye wash/shower
station
• Face shields and
goggles
• Arc flash gloves
• Neoprene aprons
• Plexiglass/lexan
barrier
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Battery Charging and Testing
• Competition charger
– Charges eight cells
– Needs galvanized isolation
• Battery Lab charger
– Charges many cell chemistries
– One to eight cells series lithium packs
– Balancing system with up to one amp shunting
current
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Low Voltage Diagram
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Control Modes
• Test
– Charge batteries
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Electric Drag
Hybrid Drag
Autocross
Endurance
Data
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Physical Layout of Data and Control
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Control Components
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Processors
Accelerometers
Wheel speed sensor
CAN network
SD card storage
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Post data processing
• Recreate the track
– Better routes?
– Braking too late?
• Refine models
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Challenges
• Determining good vs. bad batteries
• Water proofing
• Interconnections
– How, where, cost
• Understanding interconnection with engine
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Final Testing
• Kibbie Dome parking lot
• Shift timing
– Machines reengaging
– Optimal shift speed
• Driver training/selection
• Benchmarking
– Checking 75m drag time
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Reflections
• Trust your teammates
• Let distributors/manufacturers help
• Terminals/connections
– Easy on paper, not as straightforward physically
• Start thesis early
– One semester may not even be enough
– Formatting is very specific
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Future Work
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4/0AWG replacement
Better state of charge measurement
Regenerative braking
Ultra capacitors
Driver Advisory System
Traction control
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Funding
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NIATT
ASUI
ESAC
College of Engineering
Competition donors
– Bender, Graybar, LEM, Biketronics
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Questions
• Event website
– www.formula-hybrid.org
• Team website
– seniordesign.engr.uidaho.edu/20102011/hybridformula/
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