1. Lafayette Photovoltaic Research and Development System 2010

2. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

3. What is the Lafayette Photovoltaic Research and Development System? PV Array Subject to a Statement of Work Commercial Grid Tie Inverter Requirements based team oriented capstone project 2kW solar energy system that converts high voltage DC to 120V AC RMS signal of 60Hz A test space for students to learn about energy issues and power engineering.

4. Main Requirements Automatic charge and discharge the LiFePO 4 batteries Delivery of 120V RMS, 60Hz ± 0.05% AC Monitor, store and display real time temperature, voltage, and current data from all subsystems Safety precautions to safely shut down the system if a fault is detected

5. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

6. Project Team Began in 2009 with a 22 student and 2 professor team 2010 team consists of 14 students along with the 2 original professors. Over 40 people have contributed to this project

7. Systems Engineering Exposure Much of today’s engineering is system engineering – System architecture issues – Interface design and documentation – Configuration management – Scheduling Opportunity to manage complexity

8. Other Engineering Exposure Exposure to mechanical issues – Most ECEs have little exposure to mechanical issues Board layout Subsystem Box layout Assembly drawings Exposure to safety issues – Safety lecture – Safety plan Students limited to 30V Lock out tag out – Must design with safety in mind! High voltage isolation HV/LV separation

9. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

10. System Block Diagram

11. System Block Diagram - PV PV Array converts solar energy to electrical energy

12. System Block Diagram - RPI The RPI Accepts high voltage DC from the PV array and delivers it to the rest of the system Main safety hub

13. System Block Diagram - ESS Battery Bank consisting of 64 3.2V Lithium Iron Phosphate Batteries Creates 12V for other systems

14. System Block Diagram - FIB Receives high voltage DC and converts it into a 120V RMS sinusoidal AC signal of 60 Hz

15. System Block Diagram - SC Regulates the high voltage path between the PV, batteries (ESS), and the filter/inverter (FIB)

16. System Block Diagram - SCADA Higher-level operation Data collection of the other subsystems.

17. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

18. 2009 vs. 2010 Subsystem Comparison Subsystem2009 Status2010 Status RPIMade complete subsystemReused 2009 subsystem with minor rework ESSMade complete subsystemReused 2009 subsystem with minor rework FIBPrototype made but explosion occurred and also did not meet frequency or THD specifications Using the same topology; made a new filter and inverter that meets specifications SCNot madeCreated a new subsystem to better enable battery and energy management SCADANot Integrated with rest of system, but made Data Acquisition boards Used 2009 Data Acquisition Boards with minor rework and used ~100 lines of last years code. Added ~5000 lines of code and working website monitoring and displaying both LPRDS and the Sunny Boy

19. 2009 vs. 2010 Miscellaneous Comparison 2009 Status2010 Status PCB Boards DesignedDesigned 7 (1 redesigned twice) Reused 1, redesigned 1, and designed 1 from scratch Demo App and Tower Aesthetics Had a poster with LEDs that was displayed on the tower; PicoLCD Commercially bought lettering; PicoLCD; bright LED’s; Demo App using LCD display monitor Cables kits1422 Subsystems4Reused 2, redesigned 1, designed 2 Subsystem Connectors2740

20. 2009 to 2010 Major Changes Power management algorithm (SC) Working inverter/filter Integrated SCADA Demonstration application

21. 2009 Top Level Diagram Comparison

22. 2010 Top Level System Diagram

23. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

24. System Testing Subsystem QA Low Voltage Testing – Basic System Functionality – Battery Management High Voltage Testing Reliability and Maintainability

25. Switch Controller (SC) Regulates the high voltage path between the PV, batteries (ESS), and the filter/inverter (FIB) Student Designed Data Acquisition PCB Board Student Designed Box Layout and Wiring Scheme

27. SC ALGORITHM

31. BATT MGMT APP STATE TRANSITION DIAGRAM SoC Thresholds: 100% = 235V 65% = 205V 55% = 195V 20% = 165V

32. State of Charge

33. Low Voltage Testing Connect the system for DC Load Integration PV DC Source Disconnect FIB DC Load

34. Force LPRDS through all possible state transitions Attempt illegal state transitions Low Voltage Testing- Basic Functionality

35. Force the SC through all possible state transitions Two transitions should not occur Low Voltage Testing- Battery Management

36. Reliability and Maintainability Test Run the DC Load Integrated system for 24 hours No unexpected faults or failures occur No components overheat

37. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

38. Filter Inverter Box (FIB) Consists of: – H-Bridge – Low Pass Filter – Microcontroller FIB PICTURE Receives high voltage DC and converts it into a 120V RMS AC signal of 60 Hz Student Designed Low Pass Filter Student Designed H Bridge PCB Board Student Programmed Microcontroller Student Designed Box Layout and Wiring Scheme

39. AC Inverter Microcontroller controls IGBT inputs by Pulse Width Modulation 4 high power insulated gate bipolar transistors (IGBT’s) in H-bridge – Allows voltage to be alternated in opposite directions to create sine wave

40. Filter/Transformer Filter – Removes switching frequency – THD of less than 3% required Transformer – Reference output of FIB to building ground – Isolates the connection to the load

41. FIB Testing Requirements Frequency = 60Hz ±.05% Amplitude = 120Vrms ± 5% Total Harmonic Distortion (THD) < 3% Conducted emissions requirement of average Amplitude at 150KHz < -54dB and peak at 150KHz of < -41dB

42. Frequency Testing Test setup – Oscilloscope with inputs from: Signal generator Differential output of filter – Hold one waveform on scope and time a full cycle of the other waveform across the first waveform – The inverse of this time is the frequency difference

43. Frequency Results Time 204s Frequency difference 1/204s.0049Hz Spec: 60Hz±.05% Measured: +0.008% Result………..PASS

44. Amplitude Testing Set power supply to nominal battery voltage (205Vdc) Plug in wall transformer to output of system Measure the RMS voltage on oscilloscope Scale by factor of transformer Specification: 120VACrms ± 5% Result: 119VAC ….……………………………….. PASS

45. Capture waveform on digital oscilloscope Import data into MATLAB Write program to calculate THD Run program Specification: 3% THD THD Testing

46. THD Results THD calculated to be.157%.......................................................................PASS

47. Conducted Emissions Testing Capture data on a digital oscilloscope Import data into MATLAB Calculate the FFT from the output waveform Examine results above 150KHz

48. Conducted Emissions Results Peak at -16.93dB…………………………………………………………………………………Inconclusive

49. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

50. Supervisory Control and Data Acquisition (SCADA) Controls higher level operation and collects data from each subsystem – State Manager App – Battery Management App – Maintenance App – Demo App

51. Software Top Level Diagram

52. Data Acquisition Boards Reused from last year with a few minor changes. 4 boards total: RPI DAQ, ESS DAQ, SC DAQ, and FIB PCB. Serve as a hardware interface to sensors and switches.

53. Sunny Boy Communication Communication established with the Sunny Boy inverter using RS-485. Did not have to buy the Sunny Beam, saving $280 Available Sunny Boy Data: – Total energy saved – Voltage and current being delivered to the grid – voltage and current drawn from the PV array – AC output frequency

54. MySQL Database Stores system information – Sensor Readings – Fault and Event Logs – System State Allows for long term data analysis – Solar panel performance by month or season – energy generated per year Space to store over 5 years of data Provides the website with data

55. Website Directly interacts with the database using PHP. View data from any sensor over a specified date range. View logs stored in the database over a specified date range. lprds.aec.lafayette.edu

56. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

57. Tower Display LED indicator lights Demo App on LCD display Pico LCD indicating system state FIB & SC- digital meters for voltage, current, and temperature System output- Analog gauges showing voltage and frequency

58. Demo App Goal: educate passersby about LPRDS and demonstrate system capabilities Simple descriptions, diagrams and live data Simple user interface Coded in C++ using QT and the LPRDS API Upcoming Hardware Expansions – Touch sensor navigation – Demo outlet control

59. Demo App Screenshots

60. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

61. Safety Loop Safety is an integral part of our system – Each subsystem contains part of the safety loop – Safety loop must be closed in order enter and stay in the operational state Safety loop consists of 4 wires – Two for the loop itself – “Safety 12” which signals if the safety loop is closed – “Safety 12” ground

62. Safety Loop Diagram

63. Safety Loop Hardware SCADA Interface Box (SIB) – Purchased for USB controlled relay & digital input ports – Added feature of two RS485 ports Safety to Software Interface Board – Designed to control the alarm – Ends the safety loop with the big red emergency button ALARM

64. Presentation Outline System Introduction Project Team System Block Diagram 2009 vs. 2010 Comparison 2010 System Focus – Switch Controller (SC) – Filter Inverter Box (FIB) – Supervisory Control and Data Acquisition (SCADA) – Demo App and Tower Design – Safety Loop and Hardware Project Status

65. Budget – Current Spending Section Breakdown SCADA$ 229.45 Conn. & Cables$ 133.99 FIB$ 935.51 ESS$ 58.93 SC$ 103.79 DAQs$ 417.65 Snubbers$ 82.61 Andy Misc.$ 174.66 AC Load$ 612.79 TOTAL SPENT:$ 2,749.38 Remaining:$ 250.62

66. Power Budget RPI: 3.89W ESS: 1.42W SC:.9W FIB: 6.03W SCADA: 7W Safety & Display: 1.29W DAQ Boards: 3.99W Total: 25W Amount Allowed: 37.5W

67. Major Requirements Achieved Raw Power Interface – Contains main logic for safety Energy Storage System – ESS provides LVDC power for all subsystems Filter-Inverter Box – Provide 120V RMS, 60Hz AC power Supervisory Control And Data Acquisition – Perform supervisory functions on all subsystems – Log system data (sensors, states) into the database, retrievable on the website Safety – All subsystems must be connected to the safety interface Demo and Display

68. Major Requirements to be Achieved Switch Controller – Switching algorithm Supervisory Control And Data Acquisition – Operational States Power Independence – FIT PC, display monitor Documentation – Must be complete and correct

69. Major Requirements Not Achieved Energy Storage System – Per-cell management – Standalone operation – Internally protected from excessive charge/discharge Filter-Inverter Box – Measure phase angle between voltage and current, and power factor Supervisory Control And Data Acquisition – Monitor voltage, current, and temperature in all subsystems HV PV Integration

70. Future Improvements Meet the requirements we are not meeting – Snubbers for when incorporating PV Array – Single Cell Battery Management – Power independence System Control via website Maximum Power Point Tracking Demo Touch Sensors

71. Special Thanks To: Dr. Jemison Professor Nadovich Andy Langoussis Nicolette Stavrovsky

72. Questions?