1. P12407- Clean, Self-Sustained Photovoltaic Energy Harvesting System Josh Stephenson Mike Grolling Thomas Praderio KGCOE MSD TECHNICAL REVIEW

2. PROJECT OBJECTIVE Utilize and properly manage energy from multiple sources to drive a load or charge a battery with high efficiency for portable applications

3. CUSTOMER REQUIREMENTS Design will include safety and component failure Ability to manage inputs from multiple power sources Investigate and benchmark technologies, components and modules System will integrate power management and load distribution. Establish highly efficient energy conversion parameters and design System must manage energy source variability Provide data acquisition points for future team's display design System must be portable System must include instructions for set-up and use

4. PROJECT SPECIFICATIONS Ability to generate ~5W of power Voltage stabilization for battery charging (~15V ±0.05V) Output voltage of 10V Full solar delivery, provide a max output current of 0.5A Energy Storage is ~5 A-h Multiple solar panels Benchmark given component's specifications Calculate, design, measure each function List DAQ points Efficiencies for each function

5. PHASE 1: PRELIMINARY DESIGN Incorporates single energy source

6. (INITIAL) FINAL DESIGN

7. FINAL DESIGN

8. MAXIMUM POWER POINT TRACKING (MPPT)

9. SPV1020 MPPT IC

10. STANDARD BBC CONFIGURATION

11. STANDARD BATTERY CHARGER CONFIGURATION

12. STANDARD POWER MANAGEMENT CONFIGURATION

13. LITHIUM-ION BATTERIES

14. RISK MANAGEMENT IDRisk ItemEffectCauseLikelihoodSeverityImportanceAction to Minimize Risk 1Team runs out of timeProject doesn't get finished Poor project planning2510Good plan 2Parts arrive lateSchedule is delayedUnreliable vendor236Constant communication with Vendor 3Prototype draws too much power Poor battery lifePoor choice of technology 133Choose low power electronics 4Photovoltaic produce insufficient/minimum voltage Very low efficiency and power generation Poor pairing of solar cells with DC/DC Conv. 259Examine energy curves for different solar cells 5Buck Boost converter incapable of blocking reverse bias conditions reverse currents will drastically lower efficiency and may compromise operation or damage solar cells Poor isolation of energy sources 178Place diode across each solar cell to dissipate reverse emf 6Internal electronics produce too much heat Electronics overheat; inefficient Poor choice of electronics or casing; unrealistic goals 224Choose low power electronics 7Internal electronics do not produce acceptable signals Redesign/ project goals not met Low margins of safety/ high-risk technology 236Work with electronics that are acceptable

15. RISK MANAGEMENT IDRisk ItemEffectCauseLikelihoodSeverityImportanceAction to Minimize Risk 8Requirements change during the project Project will not be able to change in time Redesign required155Verify deliverables with customer 9Teammates do not do assigned work Team will need to do the work for the teammate Laziness/ not enough time 136Ask for help with needed 10Teammates do not arrive prepared Team will be delayed and work will be postponed Laziness/ not enough time 224Assign tasks that have a high likelihood of being completed 11Inability to contact the customer or guide May miss vital information and requirements Poor Communication224Keep constant info flow with the customer and guide 12Getting wrong information from customer Lead to solving an issue that doesn't exist Poor Communication236Set up meeting s and communicate often 13Arguments between teammatesWill hurt team morale and cause conflict between members Poor Communication224Have group focused and group leader aware 14Microcontroller not fast enough to manage power Power management will be ineffective Poor part selection225Microcontroller selected with appropriate speed 15Fractional gain op-amps use too much power Battery life will decrease Bad amplifier design265Select appropriately high-ohm feedback resistors and low- leakage op-amps 16Microcontroller code does execute properly Power management will be ineffective Poor coding478Code will be thoroughly tested and debugged

16. CHALLENGES Winter in Rochester– Forced to rely on artificial light Batteries used during experimentation were 12 years old and did not hold charge very long Flexible PV panels did not supply enough power Buck/Boost did not maintain required voltage while charging Learning curve on PCB layout software Scheduling with PCB ordering during the Chinese New Year Working with BGA footprint

17. CHALLENGES CONTINUED Express PCB or Eagle CAD? Proprietary vs. open standards Licensing and version issues Finding vendor footprints Finding LGA footprints for the buck-boost Board house selection Price, capabilities, scheduling (Chinese new year) Final decisions: Eagle 5.7 for schematic and board layout MyRo PCB for fabrication

18. MICROCONTROLLER MSP430 DETAIL VIEW

19. FRACTIONAL GAIN AMPLIFIER FOR VOLTAGE SENSING Both op amps are powered with a 3V button-cell CR2032

20. CURRENT SHUNT MONITOR INA193

21. PCB LAYOUT

22. RESULTS

23. RESULTS CONTINUED

24. FUTURE CONSIDERATIONS Troubleshoot analysis on PCB Added display for real-time data capture New batteries

25. QUESTIONS?