Transcript World Solar Challenge

The Design of the
Durham University Solar-Powered Car
DUSC
Introduction
• Development of high-performance solar car
• Good match for Durham School of Engineering
• Vehicle Design and Development
Vehicle Design
Vehicle Design - Electrical
SUN
Solar
Cells
MPPT
42 – 59 VDC
DC-DC
Converter
Solar
Cells
MPPT
multiple
units
multiple
units
in parallel
Battery
Module
3–200V
DC
Inverter
Drive
3–200V
AC var freq
Wheel
Motor
Vehicle Design - Electrical
• Solar Cells
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Use energy from the sun to generate electricity
Maximum power from the sun ~1000 W/m2
Solar cell efficiency ~16%
Area of solar panels
= 1.8 m x 5 m
= 9 m2
• Power
= 1000 W/m2 x 0.16 x 9m2
= 1440 Watts
Vehicle Design - Electrical
• Maximum Power Point Trackers (MPPTs)
• Power = Voltage x Current
• Voltage and Current from
cell both depend on sun!
• Sometimes voltage from
cell < battery voltage
• MPPTs provide the
optimum resistance to the
solar cells for maximum
power
Vehicle Design - Electrical
• Motor
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Direct-drive: no gearbox loss
High-torque / low-speed
Axial flux “pancake”
Integrated into rear wheel
1.8kW, effy ~ 95%
Can also act as brake
Has potential to be used for
real vehicles
Vehicle Design - Electrical
• Batteries
• 4 sealed gel lead acid
batteries (125 kg total)
• 48V - 5kWh capacity
•  energy collected during
typical day in UK summer
• Charge all day, drive for 2
hours at high speed
• Technical Partner
C&D Technologies
Vehicle Design - Mechanical
• Aerodynamic Design
• Aerodynamic drag increases
with velocity squared
• Rolling resistance does not
change with speed
• Aero drag dominates power
consumption at high speed
• Computer simulations (CFD)
• 10% scale parametric models
• Target CDA ~0.1m2
Vehicle Design - Mechanical
• Chassis Design
• Low mass (30kg)
• low Factor of Safety
• detailed analysis
• Computer simulations (FEA)
• Steel space frame
• Composite body shell
• On-road testing
• verify design loads
• validate simulation
The Way Forward
• (N)ASC July 2005, July 2007?
• WSC Sept 2005, Sept 2007
• Jobs to do:
• Recruit sponsors
• Spent £45,000 to date
• Need £17,000+ for spares etc, £20,000 for WSC
• Website
• Tune chassis / improve bodyshell
• Power electronics for drive motor
• Solar cell encapsulation etc
• Telemetry?
The Design of the
Durham University Solar-Powered Car
DUSC