Group Members: -Adam Lint -Chris Cockrell -Dan Hubbard Sponsors: -Dr. Herb Hess -Dr. Brian Johnson...

Group Members:

-Adam Lint

-Chris Cockrell

-Dan Hubbard

Sponsors:

-Dr. Herb Hess

-Dr. Brian Johnson

HydroFly: Fuel Cell Project

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:

• 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


•Introduction–Project Objective–Project Specs



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

Phase 1 Zero Detection Circuits



Vop(1)

Vop(2)

Vop(3)

Von(1)

Von(2)

Von(3)

Zero Detection

12 98

U1A

74HC4075

1

23

U2A

74HC86

4

56

U2B

74HC86

9

108

U2C

74HC86

Vo1

1 2U3A

74HCT04

3 4U3B

74HCT04

1122

13

U4A

74AC11

Vo2

Pulse Sequence: 1R – 3F – 2R – 1F – 3R – 2F

Vo2(t)

Vo1(t)

Zero Detection

• 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 – PCB Board

Zero Detection - Verification•Circuitry operates as expected

•Pulse width of approximately 50µs

•Slight error (~20µs) accounted for in software

Power Flow

PVfc VAMPS

Xsin ( )

QVfc VAMPS

Xcos ( )

VAMPS2

X

Given:

For 75W power flow and zero reactive power:

Xline 53.533 VAMPS 122V

Vfc 122.492V ms 0.238ms

To stay within ±10% P and Q:

120.9V VAMPS 123.1V 0.214 ms 0.262

SoftwareThree 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

StartSystem

Initialization While (1)

Switch State

Case 1

Case 2

Case 3

Case 4

Case 5

Default

Waiting for Pulse

Waiting for Falling Edge

Calculations

Zero CrossingAnalysis

PWM State

ISR

Increment OverflowCounters

Reset ISR Flag

Return

Timer 2 Overflow

Interrupt

Yes

Yes

Yes

Yes

Yes

Yes

No

No

No

No

No

Software

Waiting for Pulse


Calculations


PWM State

Start

Phase 1 Falling?

Pulse Detected and System

Synced?

System Synced

Record Times/Reset Counters

Yes

Yes

No

No Set Next State

PWM Calculations/ PWM Sync Check

Break

Software

Phase 1 Falling Reference Signal

Zero Crossing Pulse Stream

Waiting for Pulse


Calculations


PWM State

Start

Pulse Ended?

Increment/Decrement Counters

Record TimesYes

No

Set Next State


Break

Software



Waiting for Pulse


Calculations


PWM State

Start

Half Period?

Calculate Time Between Pulses

Calculate Pulse Width

Yes

No

Calculate Half Period


Break

Set Next State

Software



Waiting for Pulse


Calculations


PWM State

Start

Increment/Decrement Counters

Calculate Actual Zero Crossing with Error Adjust


Break

Set Next State

Detect Fault?Yes

No

System Shutdown

Software

Zero Crossing Pulse Stream (Fault)

Zero Crossing Pulse Stream (No Fault)

Waiting for Pulse


Calculations


PWM State

Start

Triangle Wave Rising Edge?

Convert to Q15 Format

Calculate Phase Counts

YesNo


Break

Calculate Timings/Update Carrier Frequency

Turn on PWM Output

Calculate/Load Sin Positions in CMPR Registers

Increment Counters

Increment Counters

Software


•Introduction–Project Objective–Project Specs



Problems EncounteredThree 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

Item Predicted Cost Actual ExpendituresDC/DC Converter $318.00 $398.00DC/3-Phase AC Inverter $500.00 $500.00Hydrogen $45.00 $62.50Poster/Report Binding $70.00 $70.30Protection Circuitry $50.00 $28.80Filtering (Inductor Bank) $50.00 DonatedTransformer $125.00 DonatedPrinted Circuit Boards $350.00 $180.00Circuit Components $150.00 $159.96Utility Cart $100.00 $58.00Miscellaneous $300.00 $0.00Code Composer Studio $495.00 DonatedXDS510PP-Plus Parallel Port Emulator $999.00 Donated

Total Predicted Budget $3,552.00Total Donated $1,669.00

Total Expeditures $1,395.06Total Budget Left $487.94

Budget

QUESTIONS?

DCDC

DCAC

Trans-formers and

inductor bank 　

INPUT18-36V DC

120V DC ±1%

AC 3-phase

Synchronous Freq.

Output: 208VLL

OUTPUT208V ± 2%

AC 3-phase

Synchronous Freq.

:

Zero-Detection Circuitry

Control

Y

75W

Special thanks to Greg Klemesrud, JJ, Steve Miller, Don Parks

Group Members: -Adam Lint -Chris Cockrell -Dan Hubbard Sponsors: -Dr. Herb Hess -Dr. Brian Johnson...

Documents

Transcript of Group Members: -Adam Lint -Chris Cockrell -Dan Hubbard Sponsors: -Dr. Herb Hess -Dr. Brian Johnson...