University of Washington

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University of Washington
University of WashingtonElectric Pontiac Fiero
Project

• Presented by Eric Yost

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Problem Statement

• General To convert a gas powered 88 Pontiac
  Fiero into an electric vehicle able to accelerate
  from 060 MPH in less than 5 seconds.
• Specific Design and integrate the drive train
  that best meets the requirements of the customer

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Design Problems

• Transmission
• No transmission

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Design Problems

Number and type of motors
Dual 8 motors
Single 9 motor
Permanent Magnetic Motors
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Design Problems

• Connecting the motors
• PD Belt
• Pulley and Belt
• Two-gears
• Three-Gears
• Chain

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Current Design
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Simulation

• Will be used to
• Determine manual transmission shift points for
  maximum acceleration
• Determine manual transmission shift points for
  everyday commuting
• Analyze specific components of the vehicle

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Simulation Block Diagram
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Simulation Components

• Driver
• Controller
• Motors
• Coupling System
• Transmission
• Car Dynamics

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Driver
Assumes pedal to the metal
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Controller
Simulates the electric system
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Controller II

• Equation 1
• V I R Ke ?
• V Voltage
• I Target Current 2000 amps
• R Motor Resistance 0.02 Ohms
• Ke Motor Constant 0.25
• ? Motors Angular Velocity
• This voltage is capped at 196V
• Equation 2
• I (V Ke ?) / R
• This current is divided and fed to each motor

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Controller III
Back EMF
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Motor
Equation for torque
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Coupling System
Connects the two motors together
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Transmission
Multiplies the torque and divides the RPM by the
gear ratio
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Car Dynamics
Turns the applied torque into an acceleration and
velocity
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Car Dynamics II

• Equations for Car Dynamics
• Force Equation
• Power Equation

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Ideal Simulation Results
Force Equation
0-60 Time 2.318s
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Ideal Simulation Results
Power Equation
0-60 Time 2.318s
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More Realistic Simulation Results
Force Equation
0-60 Time 4.170s
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More Realistic Simulation Results
Power Equation
0-60 Time 4.170s
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Future AdditionTire Slippage

• Two ideas of how to model tire slippage
• Realistic approach If the torque is too high,
  the tires slip
• Ideal approach The torque is capped before the
  tires can slip

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Inaccuracies

• Motor calculations
• No tire slippage
• Efficiencies
• Drag constants
• Modeling the driver

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Questions?