1. Close-to-production System Controller using Raspberry Pi and TinkerForge Hardware for an SOFC-APU Dipl.-Ing. Christian Szepanski Chemical Power Systems Coauthors: Dipl.-Ing. Yiyang Su Dipl.-Ing. Oliver Keich Dr.-Ing. Andreas Lindermeir

2. FDFC 2015 - Raspberry Pi and TinkerForge System Controller  CUTEC – Introduction  SAPIENS – Project  System Concept  Hard and Software Solutions  First Results  Conclusions Overview 2

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4. Sustainable Industrial Society 4 Information Energy Systems Analysis Resources Waste- water Eng. Metal Recycling Energy Chemical Power Systems Thermal Process Tech. CUTEC - Business Segments FDFC 2015 - Raspberry Pi and TinkerForge System Controller Public research institute 100 employees Application oriented R&D SOFC

5. FDFC 2015 - Raspberry Pi and TinkerForge System Controller  SAPIENS – Project 5 For more details please check: http://sapiens-project.eu  Project aims to design a mSOFC APU with LPG as Fuel  Integration into RV (or mobile home) SOFC Auxiliary Power In Emissions/ Noise Solutions

6. FDFC 2015 - Raspberry Pi and TinkerForge System Controller System Concept 450 mm 200 mm 150 mm Controller Filter (air intake) Fuel inlet Hot Box Exhaust 6 Valve Air blower

7. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Electric Circuit Diagram 7 U I U I I Stack (12-20 V) Load resistor (~4 Ohm) Charger (<20 A) Battery 12 V 24V converter (< 6 A) To BoP-components (parasitic consumption) U 24V 12V For TF and RP * Fuse * TF = Tinker Forge RP = Raspberry Pi To RV

8. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Solar Charger µ-PC Power electronics Sensors and actuators User-Interface 8 TinkerForge Test Bench

9. FDFC 2015 - Raspberry Pi and TinkerForge System Controller User Interface for RV-User 9 LC-Display with button control – different modes

10. FDFC 2015 - Raspberry Pi and TinkerForge System Controller User Interface (Developer Interface / not for RV-User)

11. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Start/Stop Routine 11 Start Self-check: Air and LPG pressure Self-check: Air and LPG pressure „Ignition“  mix 0 y/n Heating w/ mix 0  mix 1  mix 1/3 Temperature and Voltage ok? Heating w/ mix 0  mix 1  mix 1/3 Temperature and Voltage ok? y/n STOP Battery full? y/n Disconnect Charger Resistor ON Resistor OFF Connect Charger Standard Operation Timer SHUTDOWN

12. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Control Algorithm incl. Part Load (1/3, 2/3, 3/3 Power) 12  Adapting flow rate of LPG to measured power demand  If more LPG is supplied to stack, OP will change to a higher U/I curve  Charger takes all available current at charging voltage (≥ 14 V) 20V 14V 4A 56W 6A 84W 8A 112W Idealized U/I-chart for 16 cell stack: 1/3 of maximum LPG 2/3 of maximum LPG 3/3 of maximum LPG

13. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Standard Operation Current? Charging with part load 1/3 Resistor on Resistor on Current? 3-5A <3A >5A Charging with part load 2/3 5-7A <5A >7A Charging with full power Current? >7A ≤7A 13

14. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Cathode Air Control Routine Power Mode changed ? Decrease Airflow Decrease Airflow > 650°C < 600°C Temperature ? Air-fuel ratio for Charging with part load (1/3) 600-650°C Increase Airflow Air-fuel ratio for Charging with part load (2/3) Air-fuel ratio for Charging with full load (3/3) y/n 14

15. FDFC 2015 - Raspberry Pi and TinkerForge System Controller BoP Power Consumption 15 S DeviceSupplier Supply [V] Rated Current [mA] No. of Units Standby [W] Operation [W] Flow SensorsPosifa5253 0 0,4 Raspberry Pi B+Rasp. Pi Found.55001 2,5 TinkerForge 55010-20 0,2 2,5 DC/DC 12->24VOSKJ12141 0 0,2 Solar ChargerIVT12201 0,2 Pressure SensorFirst Sensor24234 0 2,2 Valve (LPG)Bürkert24831 0 2,0 Valve (air)ASCO Numatics242501 0 6,0(*) Cathode Blowerebm-papst240-17001 0 ~18 S ≤ 334 (*) Consumption in steady state conditions = 1W Controller Hardware  8

16. FDFC 2015 - Raspberry Pi and TinkerForge System Controller ww Start up 16 Accidental switch off of 24V supply Power consumption during startup: ≤ 21W Power consumption during startup: ≤ 21W

17. FDFC 2015 - Raspberry Pi and TinkerForge System Controller  Battery power < 0: charging Charging and Power Distribution 17 Air blower set to maximum discharging charging

18. FDFC 2015 - Raspberry Pi and TinkerForge System Controller  Controller hard- and software have been built, programmed and tested  Low power consumption in operation and standby  Automatic power management and distribution  Combination of mass produced hardware and python programming is costs and time saving  Next steps:  Adjustment of control routines to real life  Improvements of response times  Further reduction of parasitic consumption  Long term tests of the complete system in different conditions Summary and Outlook 18

19. FDFC 2015 - Raspberry Pi and TinkerForge System Controller SAPIENS is funded under Europe’s Fuel Cell and Hydrogen Joint Undertaking (FCH JU) for 36 months, from November 1, 2012: Grant Agreement No. 303415. The consortium gratefully acknowledges the support of FCH JU. Acknowledgements 19

20. SAPIENS Meeting 17.09.2014 Byebye slide 20 “What´s on telly tonight?“

21. FDFC 2015 - Raspberry Pi and TinkerForge System Controller Tinker Forge Test bench next gen. 21