cs-ee 481 spring 2006 1founder’s day, 2006 university of portland school of engineering electric...

CS-EE 481 Spring 2006

Founder’s Day, 2006 1University of Portland School of Engineering

Electric Vehicle Drive System

AuthorsSteven Arlint

Abdullah Binsaeed

Dustin Buscho

AdvisorDr. Robert J. Albright

Industry RepresentativeMr. Paul M. Menig

Freightliner



Agenda

• Introduction Dustin Buscho• Background Dustin Buscho• Methods Steven Arlint• Results Steven Arlint• Conclusions Abdullah Binsaeed• Demonstration Abdullah Binsaeed



Introduction• Light Weight Electric Vehicle Drive System• Designed for motor scooter or motorcycle• Designed to compete against gasoline based systems• It is an important technology for inner-city commuting• Solves problem of lack of purpose built electronics



Background: drive system

• Driver and vehicle weight of approximately 450 lbs.

• Target speed of 35 MPH• No target range (depends on batteries used)• Main emphasis on the motor control and feedback• Displays data



Background

• 450 lb weight is

for 170 lb. rider• Used go-kart chassis

for approximation



Background: speed of 35 MPH

• Requires adequate power in controller• 120 volts, 50 amperes continuous (6 KW)• Peak power of 15 KW• 120 volt motor and battery needed



Background: no target range

• Lead acid vs. Nickel vs. Lithium• The more money the more range



Background: displays data

• Speed• Distance• Voltage• Current• Power• Cumulative Power



Methods: initial research

• Learned industry standards• Motor types (testing and Simulink)• Control circuitry (Simulink)• Battery types (testing)



Methods: initial design

• Basic power electronics module (PSPICE)• Inexpensive motor and batteries• Chose microcontroller based control (MPLAB)• Connect the two systems (hand calculations)



Methods: first circuit build

• Simple microcontroller code (MPLAB)• Small scale (12 volts) (Oscilloscope)• Medium scale (36 volts) (Oscilloscope)



Methods: second design

• Start of second semester• 120 volt• Added control• Fail safes• Regenerative braking



Methods: final build and design

• Spring break• Digital gauge interfaced to logic control board• Sensors interfaced to digital gauge• Full version of microcontroller code (MPLAB)



Methods: Simulink



Methods: MPLAB



Methods: PSPICE120 Volts, 50% Duty cycle, 5kHz period, Full load



Methods: PSPICE120 Volts, 50% Duty cycle, 500Hz period, Full load



Methods: VisioTachometer

Throttle

Volt Meter

Logic Control

DisplayControl

Power Electronics

Main Battery

Main Contactor

Kill Switch

Motor

Fans



Results: three board architecture

• Power electronics• Logic control• Digital display gauge



Results: power electronics

• Controls power flow• Forward drive• Regenerative braking



Results: logic control

• The middle board• Controls throttle, motor, regen, cooling, relay• Designed to fail off (pull down resistors)



Results: digital display

• Interfaces to logic control board and sensors• Samples all sensors @ 60Hz.• Performs math to calculate current• Over current conditions



Testing Results

• 35 MPH achieved• Current draw of 50 amperes accelerating• Digital display gauge is operational• No over heating in electronics• Kill switch works



Areas of Improvement

• Current sensor• Microcontroller selection• Motor (ohmic loss)• Batteries (old)



Improvements: current sensor

• Measuring current

• Reason: math operations in microcontroller



Improvements: microcontroller

• General purpose

• Additional performance

• Two microcontrollers– Digital display gauge– Motor controller



Improvements: motor & batteries

• DC motor– Ohmic loss– Job done

• Lead acid batteries– Old– Internal resistance higher



Conclusions

• Purpose built electronics is key to electric vehicles• Electric motors can compete against gas engines• Being cost competitive as possible• Each person will have their reasons



Demonstration

• Driving and regenerative braking• Digital display gauges



Completed Product (side)



Completed Product (rear)

cs-ee 481 spring 2006 1founder’s day, 2006 university of portland school of engineering electric...

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