Team MotorBoard
Efficient Motor Control and Power Conversion System
Preliminary Design Review
29 January 2009
Nicholas Barr, Daniel Fargano, Kyle Simmons, Marshall Worth
Project Summary
 Design and prototype an
efficient motor control
and power conversion
system to interface
between a 200VDC
source and an AC
induction motor for both
driving and generating
power stages
Project Purpose
 Comply with IEEE Future Energy Competition
requirements
 1 kW motor
 3000 RPM cruising speed
 200 Volts DC source
 75% efficiency as a motor (3000 RPM)
 75% efficiency as a generator (3000 RPM)
 Locked rotor torque of 30 N-m, for duration of 3 to 5 seconds
 Initial load of 30 N-m and reach the speed of 3000 rpm within 3 to
5 seconds
 Quickly and safely become an alternator
Project Purpose
 Produce a viable option for industry
 Quick and efficient interface for generating and driving
 Possible application in hybrid vehicle motor drives
 Cheap and easy way to get a 3-phase, high power pure
sign wave
IEEE/APEC
 Dan and Kyle will be going
to Washington D.C.
 Feb. 13th – 17th
 Presenting IFEC progress
report to IEEE
 Attending Applied Power
Electronics Conference



Power Converters
Motor Drive
Efficiency
Motor
 3 HP, 3600 RPM general
purpose motor
 Baldor
 84% efficient at 3600
rpm
System Diagram
Control System
Control System
 LPC-P2148 Olimex devo board
 NXP LPC2148FBD64-S
 Program Memory Size:512KB
 RAM Size:40KB
 Package / Case:64-LQFP
 Speed:60MHz
 Core Processor:ARM7
 Data Converters:A/D 14; D/A 1
 Core Size:16/32-Bit
 Interface:I²C, SPI, SSP, UART, USB
Sensors
 3 Hall-effect current sensors
for a,b,c line detection
 Quadrature encoder (fancy
shaft encoder)
 Most likely optical
 Prefer absolute position
sensor
 DC line voltage sensor
 Optional (safety):
 Temperature sensor
Control Algorithm
 The objective of the controls algorithm is to sense a set of inputs




from the motor and control board and produce a corresponding
3-phase output voltage.
First we sample the current in phase A,B and C as well as the
position and speed of the rotor shaft
Second we determine the motor operating mode, motoring or
generating, and the desired speed of operation.
From these quantities the desired DC-DC converter output
voltage and phase A,B and C voltages are calculated.
Finally the controller will determine the appropriate duty cycle
to emit on the IGBT gate driver input in order to produce the
desired voltage at both the output of the DC-DC converter as
well as the phase A,B and C voltages produced by the inverter.
Power System
 195VDC line to supply
from Veriac
 Large DC supply line
capacitor
 Input from control
 Bidirectional Buck-Boost
Converter
 Input from control
 Bidirectional DC  3-
phase AC inverter
Power System
Simulated 3 Phase Waveforms
Test Methodology – Converter

Specifications:
 95%+ efficiency
 DC input to Bucked/Boosted DC output

Test:
 At specific duty cycle and input voltage -> Measure and Compare Output voltage to
theoretical output voltage determined by the conversion ratio M(D)= -D/(1-D)
 Swing the input voltage at specific duty cycle to confirm it works for various voltages
 Change the duty cycle and repeat the voltage swing to ensure the converter works at
all duty cycles and voltages
 If either of the test specifications is not met the inverter must be checked against
the schematic design of converter to ensure all components are properly placed and
have solid connections.
Test Methodology – Inverter

Specifications:
 95%+ efficiency
 DC input -> 3 phase AC output

Test:
 Swing input voltage and monitor output. Peak AC voltage should be no less than
75% of the DC value
 At each voltage level, check for clean sinusoidal AC signal and that all 3 phases are
120 degrees apart
 If either of the test specifications is not met the inverter must be checked against
the schematic design of the inverter to ensure all components are properly placed
and have solid connections.
Test Methodology – Controls
 Specifications:
 Control the gates of both the converter and inverter
 Test:
 Use a logic analyzer to make sure we are getting the correct signals
on the output terminals
 We will connect the controls to the inverter and converter to see if
it will actually control the gates of the transistors
 If the controls are not working, use the logic analyzer to check the
entire board to make sure all signals are producing correct signals
and check it against the schematic to ensure the accuracy of the
controls.
Marketability
 Society is going green  energy conservation
 Makes for more efficient use of the power
 Perfect addition to hybrid vehicles
 Many companies are focusing on hybrid-electric drive
systems but are lacking bi-directionally, specifically the
generation of power
 This could serve as a quick fix or serve as a prototype for
future drive systems
Environmental Impact &
Impact on Society
 Shift in attitudes is moving
interest towards electric vehicles
 Increasing ease and efficiency of
battery to motor interface might
allow quicker to-market designs
 Manufacturing of board can be
done in a manner which reduces
impact on environment (RoHS)
Sustainability
 Many of the parts we will be using in our project are
accessible through multiple vendors at low cost. There are
no specialty components that would limit us or this project
to purchase from any specific vendor.
 Motor designed for is very common
 Electric motors will always be used, independent of their
use in vehicles
 The most likely component to fail would be the IGBTs on
the inverter which could blow if we don’t account for
current spikes in the switching.
Manufacturability
 Will need to meet FCC/RoHS standards
 Easy to debug due to breakout pins
 The tolerances on the components shouldn’t be that big of
an issue for this project. We are aiming to have an
efficiency of at least 75% which will rely heavily on our
designs of the power electronics and the motor itself but
for individual components the tolerances of typical
resistors, capacitors, inductors, etc should be adequate for
our needs.
Costs of Manufacturing
 Should be relatively cheap and marketable/profitable
 $50 for controls
 $40 for power components
 $20-$30 for sensors/power/etc
Safety
 Potentially dangerous due to high current/voltage
 No user access to switching
 Design for shock resistance
 Proper grounding
 High voltage isolation from low voltage controls
Division of Labor
 Converter Hardware
 Buck Boost
Marshall
 Nick
 3 Phase Inverter
 Kyle
 Dan
 Controls
 Software
 Marshall
 Nick

 Propagation
Kyle
 Dan
 PCB Design
 Nick
 Kyle
 Testing/Verification
 All
 Text
 All
 Presentation
 All

Project Milestones
 CDR- part selection/bought, system schematics, basic
power system and basic microcontroller functionality
 Milestone I - all hardware working on protoboard,
sensors configured and working, and final revision of PCB
completed and sent out
 Milestone II – working prototype, PCB built and
populated
 EXPO – final debug, packaging, documentation done
Schedule Overview
 Buck-Boost Converter: Jan 19-Feb 19
 DC:AC Inverter: Jan 19-Feb 19
 PCB layout: Feb 20 – March 11
 Software: Feb 20 – April 6
 Project Completion: April 16
Money
 Primary Funding:
 Fall 2008 EEF mini-proposal applied for and received ($2k)
 Spring 2009 UROP Funding ($1k)
 Secondary Funding:
 Prize money from the IFEC 2007 competition
(~$3k)

This money needs to cover the motor design team as well
 Department funding from Lightner ($5k)
 Backup Funding:
 Professor Barnes has a large grant for student research
projects ($10k+)
Budget
Item
Quantity
Total Cost
PCB Fabrication
2
$150
Microprocessor
1
$15
Controls parts
2
$60
IGBTs
15
$375
Drivers
4
$30
Power Electronics parts
?
$20
Sensors
4
$50
Packaging
1
$100
Printing/Poster/etc
1
$75
Shipping
$90
Total
$965
Risks and Contingency Plan
 Lack of proper efficiency
 Focus on driving side, less emphasis on generating
 Hand wired motor
 Current spikes
 Designed to have peak current double what we expect
 Most parts interchangeable with higher rated
components
 PCB fabrication problems
 We can wire wrap or use devo board
Questions?