Fuel Cell Simulator System Martin Ordonez, Masters Candidate Supervisors: Dr. M. Tariq Iqbal Dr. John E. Quaicoe Faculty of Engineering and Applied Science.

Fuel Cell Simulator System

Martin Ordonez, Master’s Candidate

Supervisors:

Dr. M. Tariq Iqbal Dr. John E. Quaicoe

Faculty of Engineering and Applied ScienceMemorial University of Newfoundland

Introduction

Fuel Cells (FC)

Why FC Simulators?

Organization

Direct Methanol FC (DMFC) and Electronic Load

Description

Dynamic Behavior of a DMFC

Fast Dynamic Power Converter for FC

Simulators

Stand Alone FC Simulator

A Novel FC Simulator Based on a Small Single

FC

Conclusions

DMFC System Description

Cross section of the DMFC

Membrane Electrode Assembly

Anode and Cathode Plates

DMFC System Description

Cross section of the DMFC Actual DMFC

Electronic Load for FC Systems

Conceptual Schematic of the electronic load power stage and instrumentation

Picture of the Electronic load

An Advanced Electronic Load for FC Systems

Conceptual Schematic of the electronic load based on Digital Signal Processor (DSP)

DSP board top view

DSP board bottom view

An Advanced Electronic Load for FC Systems

The advanced electronic load Power module expansion

DMFC Steady State Characteristic Curve

FC Polarization Curve

Dynamic Behavior of a DMFC: Current Steps

Response to a series of current steps : v-i plot

Response to a series of current steps : time domain plot

Dynamic Behavior of a DMFC: Power Steps

Response to a series of power steps : v-i plot

Response to a series of power steps : time domain plot

Dynamic Behavior of a DMFC: Resistive Steps

Response to a series of resistive steps : v-i plot

Response to a series of resistive steps : time domain plot

Dynamic Behavior of a DMFC: Current Ripple

DC+AC current test for 25Hz and 400Hz: v-i plot

DC+AC current test for 25Hz and 400Hz: time domain plot

Power extraction as a percentage of the power extraction without ripple

Current Ripple Operation: Output Power Reduction

Peak Power Availability

Peak power extraction from no-load to 400mA : v-i plot

Peak power extraction from no-load to 400mA : time domain plot

TransActOhmico VVVEV

CR

VV

Ci

dt

VVd

a

TransActo

TransAct

1

FC Electrical Equivalent Model

Summary

Advanced electronic load

Dynamic behavior of a DMFC

Power reduction with current ripple operation

Peak power availability

Examination of the generic FC dynamic model

Fast Dynamic Power Converter for FC Simulators

Dynamic response requirements?

Fast dynamic responseLarge signal frequency response:

DC+AC current test for 25Hz and 400Hz: v-i plot

• Unity Gain• Negligible phase shift

Evaluation of Isolated Converters

Flyback

ForwardPush pull, half and full bridge

Following a reference signal Inductor and output current

Reversible Buck converter

Topology Selected for the Power Converter

Advantages:Avoid discontinuous conduction modeFast capacitor discharge (reverse current)Best switch utilizationSuitable for switching surface control

Control Strategy: A Simple Analogy

Which is the fastest way to travel by car?

MallUniversity

Maximum acceleration Brake!!!!

Control Strategy: A Simple Analogy

Answer: Time optimal

MallUniversity

Control Strategy: Time Optimal

Control Strategy: Parameter Change

uvvdt

vd

R

L

dt

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oo 2

2

uvtBtAtv cco sincos)exp(

A

dt

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BuvvALC

RL

LC

RC

o

cco

0

0

2

;;2

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;2

1

C

LRcd 2

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Control Strategy: Normalization

Control Strategy: Normalized Switching Surface

Control Strategy: More Switching Surfaces

Control Strategy: Facts About Switching Surfaces

Facts:

No unique SS can give a universal solution

Simple approach to predict the transient response: The closer the better

Control Strategy: Inspection of the Ideal Transient

C

LRcd 2

1

Control Strategy: Region of Convergence

Control Strategy: Control Law

Power Converter Prototype

Simulation vs. Experimental Results

More Experimental Results

Start up and resistive steps Frequency response

Summary

Analysis of the dynamic requirements

Converter topology selection

Control strategy: Selection of a SS

Prototype development

Experimental result

Stand Alone Fuel Cell Simulator

Conceptual block diagram of the system

Suitable for Laboratory operation No computer No communication cards No licensed software Small low cost system

TransActOhmico VVVEV

CR

VV

Ci

dt

VVd

a

TransActo

TransAct

1

Parameters of the Model

1)

2)

3)

4)

FC Model vs. Actual FC

DSP-based Implementation

Flow diagram of the FC model and power converter controller

FC Stack Emulation: 55 Single Cells in Series

Response to a series of current steps : v-i plot and time domain plot

Summary

Empirical model with reduced computational requirements

Development of a stand alone FC simulator based on a DSP

The most important feature: portability

Good match between the FC simulator and experimental results

A Novel FC Simulator Based on a Small Single FC

Replacing FC model for a small single FC

Include membrane drying, catalyst poisoning, aging, etc.

Avoid results that depart from reality Use of scale up rules

A Novel FC Simulator Based on a Small Single FC

Control Area Network (CAN) bus PC based monitoring and analysis Fast dynamic power converter for

FC simulators Four modes of operation

A Novel FC Simulator Based on a Small Single FC

Control Area Network (CAN) bus PC based monitoring and analysis Fast dynamic power converter for

FC simulators Three modes of operation

A Novel FC Simulator Based on a Small Single FC

Control Area Network (CAN) bus PC based monitoring and analysis Fast dynamic power converter for

FC simulators Three modes of operation

A Novel FC Simulator Based on a Small Single FC

Control Area Network (CAN) bus PC based monitoring and analysis Fast dynamic power converter for

FC simulators Three modes of operation

Operating Principle

Experimental Results: Current Ripple Operation

120 Hz current ripple operation: v-i plot and time domain plotCh1: Power converter output voltageCh2: Single FC output voltageCh3: Single FC output currentCh4: Power converter output current

Experimental Results: Current Step Response

Current step response : v-i plot and time domain plotCh1: Power converter output voltageCh2: Single FC output voltageCh3: Single FC output currentCh4: Power converter output current

Concluding Summary

• Electronic load development

• Dynamic test of DMFC

• Power converter design

• Stand alone FC simulator

• A novel FC simulator based on a single FC

Acknowledgments

Dr. T. IqbalDr. J. QuaicoeMs. Moya CrockerDr. R. VenkatesanDr. P. PickupDr. O. YepezDr. M. Koen AlonsoMr. F. GhioldiProf. R. Oros

Fuel Cell Simulator System

Martin Ordonez, Master’s CandidateSupervisors: Dr. M. Tariq Iqbal

Dr. John E. Quaicoe

Faculty of Engineering and Applied ScienceMemorial University of Newfoundland

Questions?