CEA LIST P AN- H P AN- H Smart embedded Voltage Control Sensor for - PowerPoint PPT Presentation

CEA LIST P AN- H P AN- H Smart embedded Voltage Control Sensor for individual elements of o fuel cell stack FC_tools 09 Trondheim Francis ROY Alain GIRAUD francis.roy1@mpsa.com alain.giraud@cea.fr Direction de la Recherche et de l’Innovation Automobile 1 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC project FiSYPAC is the first project which leads to the vehicle integration of GENEPAC fuel cell stacks. GENEPAC technology : Technical Achievements : high performances 1.5kW/L and 1kW/kg Speed:155 km/h H 2 = 1,1kg/100km Autonomy :500 km Life time improvement Staionary FISYPAC FISYPAC performance FCS on-line features: Vehicle architecture : Electrical motor 60°-85°C Li-Ion battery (75-500kms) 20-140A Charged by recovering energy 10-16 bars on H 2 entrance High pressure storage tank 1.5kW/L 50% of humidity 1kW/kg 2 Laboratoire d' Intégration des Systèmes et des Technologies

Outline Fisypac : the fuel cell control Specification of monitoring module Design of the module Test and validations New approach with sensors based on GMR Designs Tests and validations Conclusions 3 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC: the fuel cell control Voltage control dispersion 0,3V to 1,28V for an individual cell – 38,4V to 153,6V for the stack) – A Resolution +/-1% from 60°C to 85°C (nominal – temperature) => +/-10mV A B +/-5% from -20°C to 60°C (intermediate) – Alarm thresholds 0,4V information / 0,3V emergency – B Control loop 500ms – Board mechanical constraints Screwed on stack back-bone – No compatibility between electronic space – common standards and Individual cell plug: minimum flat cable wiring Arrangement to equilibrate flat cable wiring – between cells and board Data reading collected from cell Galvanic insulation Simple opto electronic components assume wires coming from upper part A – 1500V galvanic insulation between stack (350V with large tolerance) and vehicle grounded Opto coupling insulation CAN_1 units Treatments and Diagnosis Board organization CAN_2 Induced a splitting into three modules of the module – 12V functions embedded on the board Opto coupling insulation CAN networking CAN 1 : for each fuel cell emergency frames – Data reading collected for cell with alarm and emergency bits positioned when wires coming from lower part B thresholds are crossed CAN 2 : for each fuel cell current voltage – values Reading and diagnosys system 4 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC : transfer mechanism Galvanic insulation fixed to 1500V between fuel cells and 12V Galvanic insulation fixed to 1500V between fuel cells and 12V battery battery Opto-electronic barrel Opto-electronic barrel V/F Fuel Cell Counter Computer conversion 100100100 First conversion: linearity, few Second conversion: using counter influence of temperature functions of the computer • analog signals are affected by emissivity and photo current restitution in presence of temperature • binary signals are less sensible to opto barrel 5 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC: cell for measuring Supply cell = PR(i+20) AA extern supply Printed board AS converted cell voltage Measured cell = PR(i+1) mock-up AC(i) shut down AM extern ground Ground PR(i) Opto barrel Cell supply Regulator Opto barrel Ground cell V/F Measured cell conversion Regulator Cell supply V/F conversion Opto barrel Ground cell Measured cell 6 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC : scanning, treatment and transfer Prototyping board (as near as possible final embedded board) – ARM MAC7111 (automotive guarantees) – I/O, timers – CAN – JTAG probe for downloading and debugging – Development PC with debuggind, dowlnoading, compiler and CAN interface Binary to counted signals Best choice for timer conversion functions – JTAG debug Test bench combining mock-up with 12 measurements – cells, prototype board and sell simulation ARM MAC7111 (supply) Embedded software nearby FISYPAC microcontroller – application Results Available I/O For each measured cell, linearity of computed and counters – data versus analog supply simulating cell voltage External supply to replace fuel cell • 10mV increments to verify accuracy and 2 CAN drivers • repeatability Computation to determine coefficients of linear – function which identify the transfer response of measurement cell Control of emergency thresholds – CAN frames organization (automotive protocol) – 7 Laboratoire d' Intégration des Systèmes et des Technologies

Monitoring module : some results Mock-up validation – Precision < 10mV effective – No significant variation du to temperature or batches dispersion – Efficient calibration Convert. tension/fréquence AD654_circuit 1, régulateur LM 2936 et optocoupleur HCPL063L à différents paliers de température (tens. entrée conv. = 0,6V, tens. sortie opto. = 3,3V) 58850 3000 2500 58800 Fréquence sortie optocoupleu 2000 Cell voltage (mV) fréq.@ 85°C 58750 fréq.@ 60°C 1500 fréq.@ 20°C 58700 fréq.@ 0°C Série1 Série2 Série3 fréq.@ -20°C 1000 58650 500 Série7 Série9 58600 0 0 1000 2000 3000 4000 5000 6000 7000 58550 5 10 15 20 25 Digital counting Tension entrée régulateur (V) 8 Laboratoire d' Intégration des Systèmes et des Technologies

1400 1400 1200 1200 Computed cell voltage (mV) Changing of battery Computed cell voltage (mV) 1000 n°10 1000 VOIE_0 VOIE_1 VOIE_2 VOIE_3 VOIE_4 VOIE_5 800 VOIE_6 VOIE_7 VOIE_8 800 VOIE_0 VOIE_1 VOIE_2 VOIE_9 VOIE_10 VOIE_11 VOIE_3 VOIE_4 VOIE_5 600 600 VOIE_6 VOIE_7 VOIE_8 VOIE_9 VOIE_10 VOIE_11 400 400 200 New threshold 200 (300mV) 0 0 1 101 201 301 401 1 101 201 301 401 Scrutations Scanning loop Computed voltage – Computed voltage restitute correct cell voltage – Occurrence of event (modification of threshold voltage, exchange of batteries – Without further temperature tests 9 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC : final board JTAGconnec tors Prototype board Automatic – Design based of 12 cells mock- purge of cells ups CAN connectors – Use of printed boards layers to equilibrate charge of the pile and access to the counters of treatment module – calibration of all elements Full remote on- – Final validation of embedded line monitoring software (automotive protocol PSA) – Test and validation at LITEN facility – Test and validation in-situ in Futur on-line automotive conditions monitoring • In lab conditions • On-going on road conditions 10 Laboratoire d' Intégration des Systèmes et des Technologies

820 60 940 100 800 Computed cell voltage(mV) 80 40 920 780 Computed voltage(mV) Difference (mV) 60 Diffrence(mV) 760 20 900 40 740 720 20 0 880 700 0 carte banc 680 -20 860 prototype board delta -20 PSA facility 660 Difference 640 -40 -40 840 0 40 80 120 160 200 240 0 40 80 120 160 200 240 Cell identifiers (pile FISYPAC) Cells identifers (FISYPAC stack) Diagnosys 1000 board Computed cell voltage (mV) 900 800 Flat cable to the stack 700 Ombilic of flat cables 600 Tests on LITEN facility 0 20 40 60 80 100 120 Cell identifiant (carte 1) 11 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC: GMR technology Vsup 2 Bias lines 1,5 I bias 1mA 1 1mA U (V) 2mA GMR 2mA 0,5 V stack 2.96mA V GMR 2.96mA Ibias (mA) 3mA cell 0 3mA -70 -50 -30 -10 10 30 50 70 4mA or -0,5 4mA 4,44mA V cell Variable 4,44mA -1 resistors -1,5 ground -2 Features: • a current circulating into bias lines induces a magnetic field detected by resistors which value depend of the magnetic field encountered (nanned GMR). • The magnetic field is not affected by the insulation layers between bias lines and GMR resistor, which allows an intrinsic galvanic insulation • The linearity of the conversion is very efficient Individual Bias GMR Amplifiers CA/N Computing fuel cell current 100100100 12 Laboratoire d' Intégration des Systèmes et des Technologies

FISYPAC : behavior of a single GMR cell Behavior of a single GMR Single GMR cell – Very linear comportment of cell voltage conversion Amplification – Inherent low offset – Sensitivity to temperature • Appears as homogeneous and Bias line and cell voltage linear simulation • Computed correction (treatment module) 40 ESSAI • Compensation by technology • Not possibility to evaluate lot 20 Vin+ - Vin- / mV effect production 0 – Next step, design of a barrel VIN+ - VIN-(mV à 20°C) -20 VIN+ - VIN-(mV à 40°C) VIN+ - VIN-(mV à 60°C) VIN+ -VIN- (mV à 85°C) VIN+ - VIN-(mV à 0°C) VIN+ - VIN- (mV à -20°C) -40 0 0,5 1 1,5 2 2,5 3 Vcel / V 13 Laboratoire d' Intégration des Systèmes et des Technologies