University of Washington Presented by Eric Yost University of Washington Electric Pontiac Fiero Project

General: To convert a gas powered ’88 Pontiac Fiero into an electric vehicle able to accelerate from 0–60 MPH in less than 5 seconds. Specific: Design and integrate the drive train that best meets the requirements of the customer Problem Statement:

Design Problems:

Dual 8” motorsSingle 9” motor Permanent Magnetic Motors Number and type of motors: Design Problems:

Current Design:

Simulation: Will be used to: –D–Determine manual transmission shift points for maximum acceleration –D–Determine manual transmission shift points for everyday commuting –A–Analyze specific components of the vehicle

Simulation Block Diagram:

Simulation Components: Driver Controller Motors Coupling System Transmission Car Dynamics

Driver: Assumes pedal to the metal

Controller: Simulates the electric system

Controller II: Equation 1: V = I R + K e ω –V–V: Voltage –I–I: Target Current ≈ 2000 amps –R–R: Motor Resistance ≈ 0.02 Ohms –K–K e : Motor Constant ≈ 0.25 –ω–ω: Motor’s Angular Velocity This voltage is capped at 196V Equation 2: I = (V – K e ω) / R This current is divided and fed to each motor

Controller III: Back EMF

Motor: Equation for torque:

Coupling System: Connects the two motors together

Transmission: Multiplies the torque and divides the RPM by the gear ratio

Car Dynamics: Turns the applied torque into an acceleration and velocity

Car Dynamics II: Equations for Car Dynamics: –Force Equation: –Power Equation:

Ideal Simulation Results: Force Equation: 0-60 Time: 2.318s

Ideal Simulation Results: 0-60 Time: 2.318s Power Equation:

More Realistic Simulation Results: Force Equation: 0-60 Time: 4.170s

More Realistic Simulation Results: Power Equation: 0-60 Time: 4.170s

Future Addition: Tire 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

Inaccuracies: Motor calculations No tire slippage Efficiencies Drag constants Modeling the driver

Questions?