Motivation

1. SOLAR array MONITOR(s.a.M.)Group 14Will AdrobelMohammed Jebaristephen R. parkermike telladiraSponsored by QuickBeam Energy

2. Growing demand for all solar power devices • Increasingly larger arrays • Government tax credit • Closer monitoring needed • Troubleshooting is laborious • Lots of money lost due to bad panels. • Government programs require documentation Motivation

3. Monitoring capacity 5 strings of solar panels • Cost <$5 per solar panel • Frequency of reporting <15 minutes Specifications • Physical size 5"x 7“x2” • Transmission wireless or direct wire • Lifetime 15 to 20 years.

4. S.A.M. Block Diagram • Picture below shows S.A.M. installed inside the combiner box.

5. Current sensor Mohammed Jebari

6. Current sensor spec. • Operates on 5Vdc • Low power consumption • Resist to temperature changes • Handle a voltage up to 500V • Short response time • Easy to install • Very cheap

7. Comparison

8. CSA-1V sentronBasic electrical connection diagram • Pins 4, 6 & 7 are used for factory programming. • Pins 4 & 7 should be terminated to VDD (Pin 2) • Pin 6 should be terminated to GND (Pin 5)

9. Single ended output config.

10. differential output config. • S.A.M. uses differential output configuration

11. Current Measurement • CSA-1V differential output voltage for a circular conductor (wire) located on top of the IC can be approximated with the equation: • d = distance (mm) from chip surface to center of wire • I = Current in conductor

12. Interface circuits • Differential to single ended, 0-5V swing for DC current. • Gain of 20 • Output level be no more than 2.5 +/- 2.0 volts to prevent electrical saturation and non-linearity

13. The absolute accuracy of the current measurement depends on several factors which are: • Distance between the conductor and sensor • The closest the conductor to the sensor, the highest the accuracy will be • Stray fields • The sensor is an open filed magnetic sensor therefore it can sense fields from other sources Accuracy considerations

14. Acc. considerations (CONT.) The conductor position should be the same for each part in a production run. The conductor should form right angle will minimize any pickup from adjacent conductors. • The higher the current and closeness of the conductor to the IC, the more accurate the reading will be.

15. Sensitivity variation • The variation in magnetic sensitivity of the CSA-1V is +/- 3%. • DC Offset voltage • Specified to +/-15mV max • Temperature • Temperature changes affect magnetic sensitivity and DC offset voltage Acc. considerations (CONT.)

16. Temp. affects on offset volt. • DC offset voltage changes as temperature varies • Offset drift change is between -0.2 and 0.2 (mV/°C) • Add temp. sensor • Off. drift = K*∆T

17. Temperature sensor LM34DS18B20 • 1-Wire digital thermometer • 3V to 5.5V, 90µA • Measure temp. -67°F to +257°F • ±33°F Accuracy 14°F to +185°C • Can Be Powered from Data Line • Price $4.25 • Analog temperature sensor • 3V to 5.5V, 90µA • Measure temp. −40° to +230°F • ±1.0°F accuracy (at +77°F) < ±2.0°F • Output of 10mV per degree F • Price $ 2.51

18. LM34 is an analog temperature sensor, its voltage output can be affected by noise. • Add 0.1 µF capacitor between the power and the ground pin. • Reduce the effects of noise picked up on the Signal line. • Improve the stability of the measurement. LM34 Temp. sensor

19. Affect of temperature • The affect of temperature on the output voltage is very low. • The changes in the output voltage is less than 40mV for all the sensors.

20. CSA-1V Calibration • All sensors have almost the same slope 0.299 to 0.319 • At 0.05Amp, each sensor has different output voltage. • Adding 20kΩ potentiometer at the differential output of each sensor will help in adjusting the first value of the output voltage.

21. CSA-1V Calibration (Cont.) • After tuning the potentiometers, the current sensors now have the same voltage output at 0.05Amp.

22. Voltage divider • Low current drain • Low power consumption less than 0.155 mW • Voltage divider ratio 100:1

23. Stephen R. Parker microcontroller

24. Bits of precision in the AD measurements: 12 bits yields 212 – 1 = 4095 increments Max 600 volts / 4095 = .147 volts of discrimination 10 bits yields 210 –1 = 1023 600 / 1023 = .59 volts of discrimination • Number of A/D pins: 6 input lines x 2 measurements = 12 • Desirability of integrating stages into one chip: Nice but $$ • Price: Powerful microcontrollers for less than $10 micro. requirement

25. Micro. requirement (cont.) • Power requirements: drawing from UNLIMITED power source • Operating temperature: Must endure 40°C to 85°C • Connectivity: USART • Software programmable:C language compiler available • Case: DIP (dual inline packaging) for using on a breadboard

26. Micro. alternatives

27. Memory 8 bit , 2K x 8 RAM • Program memory FLASH • Speed 48 MHz • Connectivity USART module, USB • A/D channels 13 pins • A/D bits 12 • Power 4.5 - 5.5 volts • Power dissipation absolute maximum 1 W • Packaging 40 pin DIP • Operating temp. -40°C to 85°C Processor PIC18 F 4458

28. Micro. circuit connections

29. Software Flow Chart

30. Transmission William Adrovel

31. SENSOR DATA BANDWIDTH • 1 A/D Sample from sensor = 12 bits • XXXXXXXX XXXX • 1 Sample will require 2 Bytes for storage • XXXXXXXX XXXX0000 • We will sample 11 Channels every 2 seconds at 2 Bytes each • 11 bytes of data/second … very little amount of data Transmission

32. METHODS OF TRANSMISSION • Wired • DB9 Serial to Ethernet • Simplest and lowest cost • Winter Haven will have this solution • Wireless • XBEE Transmission (cont.)

33. Types of QuickBeam Projects • Commecial • Office Building • Winter Haven: DB9 Connection • Ethernet • Distributed Solar Arrays • Wireless • Residential • Wired : DB9 or Ethernet Connection Transmission (cont.)

34. UART for Serial Transmission • Serial to Ethernet protocol converter - WIZ110SR • WIZ110SR connects to onsite router or switch and will push data to QuickBeam’s FTP Server every two seconds • WIZ110SR can be set up for Dynamic or Static IP • Winter Haven will have Static IP address Winter Haven S.A.M.

35. Mike Telladira Power supply

36. Distributed 5Vdc Power System 5 Hall effect sensors: 5Vdc at 9mA each = 54mA Microprocessor: 5Vdc at 90mA = 90mA Ethernet Adaptor WIZ110SR = 180mA _____________________________ Total = 315mA

37. LM 22675-5.0 • 4.5V to 42V • Up to 1 Amp • Webench support • Few components, smaller footprint • Gerber file -Yes • Evaluation PCB -Yes Choosing the Buck Regulator

38. 5Vdc Buck Regulator Circuit Inductor Diode LM22675-5 chip

39. Why use the Evaluation PCB Inductor LM22675-5 Cinx Diode

40. Hybrid Power System 3.3Vdc Buck Key Criteria: 90% efficient Has an Enable pin

41. Step down methods Transformer 1. To insure that when QuickBeam’s panels are producing at least 180Vdc the S.A.M is powered 2. But needs to have a low power loss. In Series Voltage Divider Transformer issues: 1. Interlacing 2. Interweaving 1.5watts / (85% eff) /16V = 110.3mA Imax = 191mA

42. Atleast 12V • 10 to 20 watts • NOT for a trickle charger • 1/100 C.C. • Work in low light • Thin Film vs. Polycrystalline Solar panel selection criteria

43. ProjectBudget

44. Budget

45. Questions