GRAMMInternational Future Energy Challenge ‘07

Geoff Sanders, Richard Tan, Ankit Tripathi, Maung Myat, and Marc Hesse

Versamachine

OverviewPurposeSpecificationsSystem Description System Layout/BreakdownLabor DistributionFuture Schedule to meetMarketability/Impacts and SustainabilityChallengesRisks and ContingenciesQuestions/Suggestions and Comments

PurposeElectric machine (motor):

Works both as a starter (motoring) and an alternator (generator)

Target: Electric Car, Hybrid Electric Car

Reasons:IFEC ’07 challengeSave SpaceDecrease Cost Increase Efficiency

SpecificationsMust provide 30 Nm of Torque startup.Must motor up to 3000 rpm in 3-5 secondsMust generate 1 KW of powerMust be at least 75% efficientMust use NEMA frame 56, which is less than 7 inches in diameter

http://www.leeson.com/

System DescriptionA two pole induction machine (motor)Inverter/RectifierMotor Drivers Gate Drivers (MOSFET DRIVER)Micro-controller (TI / Freescale)User Interface (using a CAN, RS 232 cable, PC Master)RF/Bluetooth Sensors (flux, torque, Hall, temperature, etc)Power Supply

System Layout

http://www.freescale.com/webapp/sps/site/overview.jsp?nodeId=02nQXGrrlPglzQMszY

Induction Machine (Motor)

Squirrel cage induction machine with Variable Frequency (V/f) Control

Will work on the principles of 1. Flux weakening/strengthening2. Pole changing3. Frequency Change

General Torque-Speed Characteristics

Torque-Speed curve change from starting point (30Nm) to 750 rpm

Torque-Speed curve change from 8 pole (750 rpm) to 4 pole (1500 rpm)

Torque-Speed curve change from 4 pole – 1500 rpm to 2250 rpm

Torque-Speed curve change from 4 pole – 2250 rpm to 3000 rpm

Generalized frequency and speed operation of motor

Frequency-time Diagram

Speed-time Diagram

BLOCK DIAGRAM

Converter (Inverter/Rectifier)

Converter must fulfill two functions:1) Inverter operation during starting and

motoring up to 3000rpm2) Rectifier operation during generating mode

InverterPWM Inverter

Operates during both motoring and generating modes

Converts DC supply voltage to 3 phase AC Provides excitation current to stator windings Additional specifications of the Inverter1) Input dc voltage: VDC = 200V

2) Frequency range: 10-200 Hz3) Current at low frequency of 15 Hz: Iline = 30 Apeak

4) Output voltage as high as possible for given input voltage

RectifierRectifier

Operates only during generating Converts AC current to DC in order to charge

battery Additional specification of the rectifier

Output voltage: VDC = 200V @ 10 ADC maximum or at least deliver 1 kW to the battery at 200V with efficiency of 75%

Gate/Motor DriversProvide fast change in current to drive the gates of all IGBT/MOSFET switches in the converter

Sensors, Switches & Power Supply

Sensors Operational sensors

Hall effect Temperature Position encoders

Testing Torque transducer Flux meter Universal Dynamometer

Switches winding switches

Pole changing N reduction

Power Supply 200 V DC

Motor

Motor DrivingPower

Converter

DSPOr

Micro-Controller

Memory

Hall EffectSensor

Encoder

Current Voltage

Sense

Current Voltage

Sense

Receiver

ADC

BLOCK DIAGRAM

DSP/Micro-Controller3 Primary functions Control switching of PWM inverter

IGBT/MOSFET switches Control winding switching

For pole changing To reduce windings by half during 4 pole

operation Interact with user interface to produce

desired operation

User InterfacePC Master SoftwareSerial port connection Later use RF/Bluetooth

http://www.freescale.com/files/product/doc/AN1948.pdf

PC Master Support

Freescale 56F80x 56F82x 56F85x Possibly supported by:

MC68HC08 (MC68HC908MR32) MC68HC512 MPC500

PC Master Features

Control the motor Start-up/shut-down Speed control

Read/change variablesScope slower variablesRecord fast variablesStimulate variablesSend application commands with parametersDisplay help items (block diagrams, characteristics)Remote control of application through the internet

PC Master Windows

http://www.freescale.com/files/product/doc/AN1948.pdf

Other parts

Voltage regulatorsResistors, capacitors, and heat sinksVoltage shiftersRAM/ROMADC/DACRS232 serial portUARTClocks

Task DistributionMaung/Richard

Part research and ordering Design inverter/rectifier Implement sensor circuits Circuit schematics and PCB design

Ankit/Geoff Motor design finalization and ordering User interface/system controller

Marc/Geoff User’s Manual Micro-controller coding Technical manual compilation

All Documentation Test/debug Wire-wrap prototyping

GANTT CHART

BudgetCategory Item Unit Cost Quantity Total Cost

Induction Motor $250 2 $500 Motor/Generator Custom Rotor Fabrication $1,000 1 $1,000

Stator Re-winding $500 1 $500 Power MOSFETs $20 6 $120

Motor Controller Gate Drive Board $20 1 $20 Aluminum Heat Sink $50 1 $50

Pole Changing Switches $5 6 $30 Micro-controller and Support $500 1 $500

System Controller Wireless Communication $200 1 $200 Various Sensors $100 1 $100

Flux Meter $380 1 $380 DC/AC Measurement Switch $40 1 $40

Testing and Measuring Equipment External Power Plug-in $30 1 $30 Torque Transducer $1,290 1 $1,290

Torque Sensor Cable $95 1 $95 TRD-S Position Encoder $81.50 1 $82

Other PCB fabrication $66 3 $198 Voltage regulator/resistors/caps $200 1 $200

Total $5,335

MarketabilityAlmost all motor-vehicle manufacturers in the world can use it as it would Increases overall efficiency of vehicle Decreases overall cost Take up less space

Target Manufacturing cost of $100Possible Patent

Challenges, Risks, and Contingencies

Challenges This has never been done effectively! What makes us think we will succeed where

many have failed?

Risks We could quite possibly fail to meet the IFEC

specifications with our first (capstone) design. We may be unable to make the machine

automatically shift speeds and windings

Challenges, Risks, and Contingencies

Contingencies For expo we will have a motor controlled with

our controller that will run, although it may not meet the requirements dictated by IFEC. If this occurs a permanent magnet rotor

will be designed and used in place of the squirrel cage rotor in order to increase torque and efficiency

This is beyond the scope of capstone Will be able to run each characteristic for

testing using user interface to set frequency and manually switch windings

Questions / Suggestions

http://www.smartquestion.com/images/sq_image.jpg