1. Control Why do we need system control? 1. Produce PWM
2. Synchronize AC systems
3. Control power flow
4. Protect fuel cell and interface components
5. Monitor zero crossings
6. Perform calculations

2. How are these tasks accomplished?
-DSP TMS320LF2401A TI

3. 1. Produce PWM
Seven 16-bit Pulse-Width Modulation (PWM) channels which enable:
- Three-phase inverter control

4. 2. Synchronize AC Systems
-Magnitude
-Frequency
-Phase/Zero Crossings
(30 degrees ahead)

5. 4. Protect Fuel Cell and Interface Components
Checks for undesired operating conditions
-Abnormal pulse width on zero crossings
-Frequency variation
-Voltage differences

6. Overall System Layout -DC/DC Converter -Inverter -Transformer -Control
-Software
-Zero Crossing
Detection

7. Software

8. Interrupt Service Routine:

9. Zero Detection
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

10. Zero Detection

11. Zero Detection Phase 1 Zero Detection Circuits
Vop(1)
Vo2
Von(1)
Vop(2)
Von(2)
Phase 2 Zero Detection Circuits
Vo1
Vop(3)
Von(3)
Phase 3 Zero Detection Circuits

12. Zero Detection Pulse Sequence: 1R – 3F – 2R – 1F – 3R – 2F Vo1(t)

13. Zero Detection – PCB Board
4-layer board – Signal 1, Signal 2, 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 (rising) ref signal
(Picture)

14. Zero Detection - Prototype

15. Current Budget* Predicted Cost Actual Expenditures Item
Donated
$999.00
XDS510PP-Plus Parallel Port Emulator
$495.00
DSP Software
$3,552
$125
$300
$100
$150
$350
$50
$35
$45
$500
$318
Predicted Cost
$866.76
$159.96
$180.00
$66.40
$500.00
$398.00
Actual Expenditures
Circuit Components
Total
Shipping
Miscellaneous
Utility Cart
Printed Circuit Boards
Filtering
Protection Circuitry
Project Display Costs
Poster/Report Binding
Hydrogen
DC/3-Phase AC Converter
DC/DC Converter
Item
*Funds received from Power Lab Budget and O’Conner/Corbit Fund

16. Zero-Detection Circuitry
QUESTIONS?
OUTPUT
208V ± 2%
AC 3-phase
Synchronous Freq.
Max 200W
70VLL AC 3-phase
Synchronous Freq.
AMPS
120V DC ±1%
70:208
Fuel
Cell
Trans-former DC DC DC AC : Y
INPUT
18-36V DC
Control
Zero-Detection Circuitry