GRAMM
International Future Energy Challenge ‘07
Versamachine
Geoff Sanders, Richard Tan, Ankit Tripathi, Maung Myat, and
Marc Hesse
Overview
Purpose
Specifications
System Description
System Layout/Breakdown
Labor Distribution
Future Schedule to meet
Marketability/Impacts and Sustainability
Challenges
Risks and Contingencies
Questions/Suggestions and Comments
Purpose
Electric machine (motor):
Works both as a starter (motoring) and an alternator (generator)
Target:
Electric Car,
Hybrid Electric Car
Reasons:
IFEC ’07 challenge
Save Space
Decrease Cost
Increase Efficiency
Specifications
Must provide 30 Nm of Torque startup.
Must motor up to 3000 rpm in 3-5 seconds
Must generate 1 KW of power
Must be at least 75% efficient
Must use NEMA frame 56, which is less than
7 inches in diameter
http://www.leeson.com/
System Description
A two pole induction machine (motor)
Inverter/Rectifier
Motor 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/strengthening
2. Pole changing
3. 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
3000rpm
2) Rectifier operation during generating mode
Inverter
PWM Inverter




1)
2)
3)
4)
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 Inverter
Input dc voltage: VDC = 200V
Frequency range: 10-200 Hz
Current at low frequency of 15 Hz: Iline = 30 Apeak
Output voltage as high as possible for given input voltage
Rectifier
Rectifier

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 Drivers
Provide 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 Driving
Power
Converter
Motor
Current
Voltage
Sense
Current
Voltage
Sense
Receiver
DSP
Or
MicroController
ADC
Memory
Encoder
Hall Effect
Sensor
BLOCK DIAGRAM
DSP/Micro-Controller
3 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 Interface
PC Master Software
Serial 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 variables
Scope slower variables
Record fast variables
Stimulate variables
Send application commands with parameters
Display 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 regulators
Resistors, capacitors, and heat sinks
Voltage shifters
RAM/ROM
ADC/DAC
RS232 serial port
UART
Clocks
Task Distribution
Maung/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
Budget
Category
Item
Induction Motor
Motor/Generator
Custom Rotor Fabrication
Stator Re-winding
Power MOSFETs
Motor Controller
Gate Drive Board
Aluminum Heat Sink
Pole Changing Switches
Micro-controller and Support
System Controller
Wireless Communication
Various Sensors
Flux Meter
DC/AC Measurement Switch
Testing and Measuring Equipment
External Power Plug-in
Torque Transducer
Torque Sensor Cable
TRD-S Position Encoder
Other
PCB fabrication
Voltage regulator/resistors/caps
Total
Unit Cost
$250
$1,000
$500
$20
$20
$50
$5
$500
$200
$100
$380
$40
$30
$1,290
$95
$81.50
$66
$200
Quantity
2
1
1
6
1
1
6
1
1
1
1
1
1
1
1
1
3
1
Total Cost
$500
$1,000
$500
$120
$20
$50
$30
$500
$200
$100
$380
$40
$30
$1,290
$95
$82
$198
$200
$5,335
Marketability
Almost 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 $100
Possible 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