DUSC

The Design of theDurham University Solar-Powered Car

Introduction

• Development of high-performance solar car• Good match for Durham School of Engineering• Vehicle Design and Development

Vehicle Design

Vehicle Design - Electrical

MPPT

MPPTSolar Cells

Solar Cells

Battery Module

DC-DC Converter

Inverter Drive

WheelMotor

42 – 59 VDC3–200V

DC3–200V

AC var freq

multiple units

multiple units

in parallel

SUN

Vehicle Design - Electrical• Solar Cells

• 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

• 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?

DUSC

The Design of theDurham University Solar-Powered Car