Transcript HydroFly: Fuel Cell Project

HydroFly:
Fuel Cell Project
Group Members:
-Adam Lint
-Chris Cockrell
-Dan Hubbard
Sponsors:
-Dr. Herb Hess
-Dr. Brian Johnson
Final Presentation Outline
•Introduction
–Project Objectives
–Project Specs
•Final Design Solution and Validation
–Individual Components
–Entire System
•Problems Encountered
•Final Steps to Completion
•Budgeting
•Questions
Objectives
–Interface a Fuel Cell to the AMPS
–Ensure Safe Operation
Functional Specifications
Overall interface design specifications:
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AC signal MUST BE present on the AMPS
18-36V DC input from the fuel cell
Output 208 +/- 2% V AC (L-L 3-phase)
Output frequency at 60Hz +/- 0.2Hz
Power flow of 75W through the interface
Dimensions: fit on cart with dimensions
32” x 27” x 18” (2 shelves)*
*not including fuel cell, transformers or inductor bank
Final Presentation Outline
•Introduction
–Project Objective
–Project Specs
•Final Design Solution and Validation
–Individual Components
–Entire System
•Problems Encountered
•Final Steps to Completion
•Budgeting
•Questions
DC/DC Converter
•ABSOLPULSE BAP265 - Customized
–Input 18 – 36 VDC
•Protection: Current limiting, thermal fuse, reverse
polarity protection, 500VDC isolation from
output/chassis
–Output 120VDC ±1%
•Protection: Current limiting, thermal shutdown
–Power capability: 200W
–Efficiency: ~80% (within 0º – 50ºC)
–Cost: ~$318.00
DC/DC Converter
•Verification
–Input and output specifications exceeded
–Device operates efficiently at 160W
•not tested at 200W because of power supply limitations
–Measured Efficiency: 86-87%
DC/AC Inverter
•Tier Electronics – Custom Package
–Input 80-200VDC
–Output: variable 3 phase AC
–Switching circuitry: 600V IGBT devices
–Rated current: 3A RMS at 5kHz
–TI 2401 DSP: fully programmable
–I/O plug
• +15V output, receive and transmit outputs, auxiliary
inputs and outputs (digital and analog).
–Other specifications
•Max output voltage: ~90VLLwith 120V DC input
•No Previous programming
–Cost: $500
DC/AC Inverter
•Verification
–Proper operation verified at 120V DC input
with ~6kHz switching frequency programmed
Transformers
•3 single phase transformers ( - Y connected):
–Estimated 75VA rating per phase
–Steps up voltage to 208VLL (RMS)
–Filters PWM output
–Provide a ground isolation
•Experimental Verification (120V output – single phase)
–Phase A turns ratio: 1:2.6
–Phase B turns ratio: 1:3.2
–Phase C turns ratio: 1:4.3
The different turns ratios have been accounted for in the
inverter control. The magnitude of each phase can be
adjusted to get 120VL-n on the output of each phase when
connected in  - Y configuration – this has not yet been fully
verified.
Inductor Bank
• Provides ~142mH per phase for use in
controlling power flow (experimentally
verified).
• Reduces system sensitivity to changes in
voltage magnitude and/or phase.
Zero Detection
• Board designed and built by Dan Hubbard
• Gives a timing reference to the TI-2401
DSP on the DC/AC Inverter
• Provides the ability to create a 3-phase
signal synchronized with the 3-phase
system on the AMPS and, ultimately,
control the power flow to the AMPS
Zero Detection
Zero Detection
Phase 1 Zero
Detection
Circuits
Vop(1)
Von(1)
3
2
74HC86
Vop(2)
Von(2)
Phase 2 Zero
Detection
Circuits
U2A
1
U2B
1
2
8
6
5
9
74HC86
74HC4075
Vo1
U2C
Vop(3)
9
8
10
74HC86
Von(3)
Phase 3 Zero
Detection
Circuits
U1A
4
U4A
U3A
1
2
1
2
13
12
74HCT04
74A C11
U3B
3
4
74HCT04
Vo2
Zero Detection
Vo1(t)
Pulse Sequence: 1R – 3F – 2R – 1F – 3R – 2F
Vo2(t)
Zero Detection – PCB Board
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2-layer board – Vcc, GND
Required external power supply: ±18V
On-board linear voltage regulator: 3.3V
Inputs (3): 120VAC (3-phase)
Outputs (2): serial pulse stream, phase 1
(falling) ref signal
Zero Detection - Verification
•Circuitry operates as expected
•Pulse width of approximately 50µs
•Slight error (~20µs) accounted for in software
Power Flow
Given:
P
V fc  V A MP S
 si n(  )
X
Q
V fc  V A MP S
 co s(  )
X
Xline  53.533 
V A MP S
2
X
V AMPS 122V
For 75W power flow and zero reactive power:
Vfc  122.492V
ms  0 .23 8ms
To stay within ±10% P and Q:
120.9V  VAMPS 123.1V
0.214  ms  0.262
Software
Three Main Functions
•Records/Monitors Zero Detection Points
•Gives our PWM a starting point
•Data used to dynamically adjust carrier frequency of PWM
•Detects possible faults situations and shuts off PWM
•Creates Sine-Triangle PWM
•Triangle wave carrier frequency (~ 6 kHz)
•Sine wave generated from sine lookup table
•Values passed into Compare Registers which control PWM outputs
with user-controlled dead-band time (4 us)
•Controls Power Flow
•Delta incrementally added over 100 cycles to generate a power
flow of 75 W
Software
System
Initialization
Start
While (1)
Yes
Switch State
Case 1
ISR
Increment Overflow
Counters
Yes
Waiting for Pulse
No
Case 2
Yes
Waiting for
Falling Edge
No
Reset ISR Flag
Case 3
Yes
Calculations
No
Return
Timer 2 Overflow
Interrupt
Case 4
Yes
Zero Crossing
Analysis
No
Case 5
No
Default
Yes
PWM State
Software
Start
Waiting for
Pulse
Phase 1
Falling?
Yes
System Synced
Waiting for
Falling Edge
No
Calculations
Pulse Detected
and System
Synced?
Zero Crossing
Analysis
Record Times/Reset
Counters
Yes
No
Set Next State
PWM State
PWM Calculations/
PWM Sync Check
Zero Crossing Pulse Stream
Break
Phase 1 Falling Reference Signal
Software
Start
Waiting for Pulse
Waiting for
Falling Edge
Pulse
Ended?
No
Yes
Record Times
Increment/Decrement
Counters
Calculations
Set Next State
Zero Crossing
Analysis
PWM State
PWM Calculations/
PWM Sync Check
Break
Zero Crossing Pulse Stream
Phase 1 Falling Reference Signal
Software
Start
Waiting for Pulse
Calculate Pulse Width
Waiting for
Falling Edge
Calculations
Zero Crossing
Analysis
Calculate Time
Between Pulses
Yes
Half Period?
Calculate Half Period
No
Set Next State
PWM State
PWM Calculations/
PWM Sync Check
Break
Zero Crossing Pulse Stream
Phase 1 Falling Reference Signal
Software
Start
Waiting for Pulse
Waiting for
Falling Edge
Calculate Actual Zero
Crossing with Error Adjust
Increment/Decrement
Counters
Calculations
Yes
Detect Fault?
Zero Crossing
Analysis
PWM State
System Shutdown
No
Set Next State
Zero Crossing Pulse Stream (No Fault)
PWM Calculations/
PWM Sync Check
Break
Zero Crossing Pulse Stream (Fault)
Software
Calculate Timings/Update
Carrier Frequency
Waiting for Pulse
Waiting for
Falling Edge
Calculations
Zero Crossing
Analysis
Start
No
Yes
Triangle Wave
Rising Edge?
Calculate/Load Sin
Positions in CMPR Registers
Calculate Phase Counts
Turn on PWM Output
Convert to Q15 Format
Increment Counters
PWM State
Increment Counters
PWM Calculations/
PWM Sync Check
Break
Final Presentation Outline
•Introduction
–Project Objective
–Project Specs
•Final Design Solution and Validation
–Individual Components
–Entire System
•Problems Encountered
•Final Steps to Completion
•Budgeting
•Questions
Problems Encountered
Three Main Problems
•Zero Detection Reference Signal: Triggered Falling Edge instead of Rising
•Edited software accordingly
•Resulted in simpler sine-triangle PWM software
•Transformer: Core Losses drew too much current from Fuel Cell
•Found smaller transformers
•Recalculated Turns Ratios
•TI2401 DSP: Flash Memory Damaged
•Flex-Trace Connection used to program DSP still a risk
•Ordered new DSP and is scheduled for delivery on Monday
•Expected repair date: 12/13/05
Final Steps to Completion
• Replace DSP – 12/13/05
• Finish interfacing 12/13 – 12/15
– Upload and test the code for voltage magnitude and
phase required for synchronization and power flow
• Final Demonstration 12/15
• Final Report 12/15
• User’s Manual – included in final report
Budget
Item
DC/DC Converter
DC/3-Phase AC Inverter
Hydrogen
Poster/Report Binding
Protection Circuitry
Filtering (Inductor Bank)
Transformer
Printed Circuit Boards
Circuit Components
Utility Cart
Miscellaneous
Code Composer Studio
XDS510PP-Plus Parallel Port Emulator
Predicted Cost
$318.00
$500.00
$45.00
$70.00
$50.00
$50.00
$125.00
$350.00
$150.00
$100.00
$300.00
$495.00
$999.00
Total Predicted Budget
Total Donated
Total Expeditures
Total Budget Left
Actual Expenditures
$398.00
$500.00
$62.50
$70.30
$28.80
Donated
Donated
$180.00
$159.96
$58.00
$0.00
Donated
Donated
$3,552.00
$1,669.00
$1,395.06
$487.94
QUESTIONS?
OUTPUT
75W
208V ± 2%
AC 3-phase
AC 3-phase
Synchronous Freq.
120V DC
±1%
DC
DC
DC
AC
Synchronous Freq.
Output: 208VLL
Transformers
and
inductor
bank
:Y
INPUT
18-36V DC
Control
Zero-Detection
Circuitry
Special thanks to Greg Klemesrud, JJ, Steve Miller, Don Parks