Confidential

AVL List GmbH

Juergen Rechberger

AVL THDALow Cost Fuel Cell Monitoring

| HMI2015 | 14 April 2015 | 2Public

OUTLINE

• Introduction of AVL

• State of the art – stack monitoring

• AVL approach – THDA

• THDA Instrumentation and function principle

• Market introduction

| HMI2015 | 14 April 2015 | 3Public

OUR EXPERIENCE FOR YOUR SUCCESS

AVL is the worlds largestindependent supplier ofengineering services, test systems andsimulation solutions tothe international automotive andpowertrain industry AVL – more than 60

years’ experience Involved in more than

1.500 enginedevelopment projects More than 4,000 engine

test bed installations

1.2 B€ turnover7000 employees45 affiliates

| HMI2015 | 14 April 2015 | 4Public

AVL COVERS MANY CUSTOMER SEGMENTS

InstrumentationandTest Systems

PowertrainEngineering

AdvancedSimulationTechnologies

Development of powertrains - combustion engines, hybrid systems, electric drive - simulation and test systems

TRADITIONAL CORE BUSINESS

PEM & SOFC Engineering(since 2002)

| HMI2015 | 14 April 2015 | 5Public

AVL FUEL CELL

SOFC APU3kW Diesel fuelled portable power generator for truck, marine and defence applications

SOFC CHPDevelopment of a SOFC CHP unit for decentralized power generation (>60% electrical efficiency)

AVL investigates fuel cells till 2002 with a dedicatedskill team and a laboratory (at the moment 10 fuelcell test rigs from cell testing to 150kW stack/system testing)

At the moment ~50 staff members

Focus AVL Fuel Cell:

Development-, optimization-, test- and integrationof fuel cell systems (PEM & SOFC)

Diagnoses and monitoring systems PEM and SOFC CFD simulation Component development (e.g. media supply,

reformers,…) Reliability and durability development / Validation testing Simulation / Design / Packaging / System Integration

Das Bild kann zurzeit nicht angezeigt werden.

CFD SimulationPEM & SOFC CFD simulation with multi physics code AVL FIRETM

AVL THDATM

Industry leading PEM stack monitoring (in use by 7 auto OEMs)

PEM Systems Customer specific system development and integration

| HMI2015 | 14 April 2015 | 6Public

BACKGROUND OF STACK MONITORING

*CVM: cell voltage monitoring **EMC: electromagnetic compatibility

STATE OF THE ART

•Measuring of individual single cell voltages or cell voltage pairs and analysis in terms of voltage drifts (CVM*)

•Large stack monitoring costs high instrumentation effort and elaborated wiring concepts for reliable operation (EMC**)

•Determination of failure causes or lifetime estimations are not possible

REQUIREMENT

•Real time indication of critical fuel cell conditions

•I.e. detection of cell voltage drops and its reasons set counteractions

•HW instrumentation for comprehensive stack diagnostics on level for serial application

| HMI2015 | 14 April 2015 | 7Public

150 200

AVL APPROACH FOR ONLINE FUEL CELL MONITORING

determinationof causes incase of failures

AVL THDA™ technology:harmonic distortion analysis for detection of critical cell voltage drops safe stack operation

THD & impedance characteristics: collection of criteria and classification into low media supply, liquid water droplets and (membrane) dry out allows right counteraction

Online impedance spectroscopy:extraction of component values (in non critical conditions only) and assessment maintenance information and training of lifetime models

long term effect

one common hardware approach –no CVM but 2 channels measurement only (stack voltage & current)

short term effect

voltage drift detection

ageing/degradation measurement

| HMI2015 | 14 April 2015 | 8Public

THDA INSTRUMENTATION PRINCIPLEDEMONSTRATION & TESTING PHASE

HARDWARE PRINCIPLE

1.Superimposition of a small alternating current signal burst* during operation2.(Spectral-)Analysis of signal response = voltage (thd measurement, impedance spectroscopy, statistical parameters, …) 3.Results via CAN or RS232 interface to FC controller or GUI

* iAC = typ. 1A (1mV/cell, sinusoidal, low frequency)

output data

1

23

| HMI2015 | 14 April 2015 | 9Public

DESCRIPTION OF FC-MONITORING WITH “AVL-THDA”

*patented, registered trademark

“THDA™” – Total Harmonic Distortion Analysis*

• Defects or critical conditions • local non-linearities in the transfer function

• distort a superimposed signal

• form harmonics

• Extra spectral components (i.e. harmonics) are detectable in the entire stack sum voltage

• Reduced measurement effort:

• stack voltage & stack current only

cost efficient 2 channel instrumentation

easy set-up

| HMI2015 | 14 April 2015 | 10Public

THDA – WORKING PRINCIPLE

THDA detects non-linearities in the transfer function caused by e.g. critical conditions The THD factor increases increases dramatically compared to the voltage drop. This

effect is used to detect single cell failures in very large (>=500 cells) stacks.

| HMI2015 | 14 April 2015 | 11Public

THDA SERIES PRODUCT

THDA HW ProductPlug & play - laboratory instrumentation product

Commercial release in 2015!

FC Studio

| HMI2015 | 14 April 2015 | 12Public

APPENDIX: ON-LINE MONITORING EXAMPLE

450A Dry + Flood + Low Media detection

| HMI2015 | 14 April 2015 | 13Public

450A conditioning Ox Stoich 1.65

450A conditioning Ox Stoich 1.34

APPENDIX: ON-LINE MONITORING EXAMPLE

| HMI2015 | 14 April 2015 | 14Public

450A, 120% Ox RH, 9C dT

450A, 80% Ox RH, 13C dT

APPENDIX: ON-LINE MONITORING EXAMPLE

| HMI2015 | 14 April 2015 | 15Public

APPENDIX: THDA CUSTOMER FEEDBACK

• Changing the RH from 90% to 80% at 0.1A/cm2 causesroughly 2V stack performance drop (~8mV/cell)

• THDA is able to detect small performance drop due to drying

• THDA signal is low (<5%) since the condition is not too severe, but still detectable

• THDA has good resolution for critical condition detection (<10mV/cell)

30A, 90% RH 30A, 80% RH

| HMI2015 | 14 April 2015 | 16Public

APPENDIX: THDA CUSTOMER FEEDBACK

“Demonstrated very good THDA repeatability on the same sample.Response time of THDA is very good.“

„THDA has good resolution for critical condition detection (<10mV/cell).“

„Sensitive to membrane drying, air starvation and water droplets in flow fields, especially on the cathode. Capability to do EIS on a stack level.“

“Easy set-up, quick response time, good detection resolution based on relative stack performance drop.“

| HMI2015 | 14 April 2015 | 17Public

THDA INSTRUMENTATION PRINCIPLEPRODUCT EMBEDDED

COST EFFICIENT APPROACH:full integration of THDA functions (no additional devices are needed for THDA):

a. Modulation of specific current signal pattern by power invertersmall modification of inverter is needed (by inverter company)

b. Signal measurement and analysis by existing FC controller (ECU) small modification of ECU in terms of signal input filter is needed (by ECU company); implementation of THDA SW module in to the ECU code

1. THDA algorithm is integrated to the fuel cell system contoller

2. Signal processing can be integrated into the existing power electronics!

THDA doesn‘t add HW costs to fuel cell systems, only licence agreement with AVL required!

| HMI2015 | 14 April 2015 | 18Public

SUMMARY

THDA is intended to monitor fuel cell stacks in real product applications(like FCEV, CHP, mCHP, APU,…)THDA can detect most critical stack conditions online & in real time,

even if only a single cell in large stacks is effected.In the final product application, THDA requires no additional hardware.

The THDA algorithm runs in the fuel cell system controller. Only a licence agreement with AVL is required.For demonstration and test purposes all required signal processing is

integrated into a plug and play THDA HW device, which is not neededfor final products! The laboratory THDA device has been transformed into a commercial

laboratory instrumentation product (shipments start in Q3/2015).In an internal R&D effort the methodology is at the moment developed

for SOFC and PEM electrolyzersAVL THDA has already been sucessfully validated by 7 major

automotive OEMs and various non-automotive fuel cell systemintegrators (e.g. also with ENE.FARM products)