Watt Smart Wireless Single Phase Power Monitoring System (WPMS)

1. Watt SmartWireless Single Phase Power Monitoring System(WPMS) • Kamyar G. Osgoei • Glen Nogayev • Titus Cheund • Wenqi Sun • Babak Sobhani

2. Outline • Introduction • Motivation • Existing Products • System Overview • Product Design • Test Measurements • Budget and Timeline • Business Opportunities • Problems Encountered • Future Development

3. Introduction

4. Watt Smart Inc. • Kamyar: CEO • R&D, HW, Documentation, Wireless • Titus: CFO • Funding request,R&D, Documentation, Wireless • Glen: COO • Documentation, Wireless, R&D, HW • Wenqi: CSO • HW, SW, PC Interface, Q/A • Babak: CTO • HW, SW, R&D, Q/A

5. Motivation • Improve the efficiency of your home • Consumers: save energy and money • Average household power consumption in BC is 11,000 kWh/year • BC Hydro to become energy self-sufficient by 2016

6. Existing Products • Some devices perform only basic measurements • Most products don’t have wireless option • Not accurate! • Eg. Kill-a-Watt and Blue Planet

7. Our Solution • Low cost, portable power monitor • Measure power/energy/power factor • High accuracy • Wireless capability

8. Power Background • Average power calculations • Current and voltage both sinusoidal waveforms • Power factor (pf) phase difference between the two waveforms • Reactive loads (pf = 1) • Inductive loads (pf < 1) • Consumers charged for real power (P) consumption

9. System Overview Consists of sensing and PC interface units Easy to install and maintain Wireless communication with PC Capable of monitoring several units Provides kW, kWh, and electricity cost

10. System Overview High level system design Current and voltage inputs Power, energy and power factor outputs

11. System Overview Sensing unit design Current transformer (CT) PIC microcontroller XBee wireless module

12. System Overview PC interface unit design XBee receiver Data acquisition software Graphing application

13. What is measured? Why? What? Power, measured in kW. Why? It gives us a sense of the rate at which we are consuming energy (J/S).

14. What is measured? Why? What? Power Factor Why? It a measure of real power consumption to reactive power flow.

15. What is measured? Why? What? Real time energy consumption cost, shown in Canadian dollars. Why? You tell me!

16. Power Theory and Technical Implementation: 1-Theory behind calculations 2-Hardware (Sensing Unit) 3-Software (PC Interface Unit)

17. Theory Process of calculating power factor, power and real time cost: 1-Data acquisition (Voltage and Current). 2-Filtering voltage and Fourier transforming current. 3-Calculating THD factor. 4-Calculating PF. 5-Calculating Power. 6-Calculating real time cost.

18. Theory (Data Acquisition)

19. Theory (Data Acquisition)

20. Theory (Filtering Voltage)

21. Theory (DFT of Current)

22. Theory (DFT of Current)

23. True Power Factor or Not So Much True Power Factor, That Is The Question!!

24. Theory (Calculating Power) P=Vrms*Irms*PF

25. Theory (Calculating Real Time Cost) Real time cost=(Power in kW)*1h*($ per kWh)

26. Hardware – Sensing Unit 1-Power Supply Unit 2-Signal Conditioning Unit 3-MCU Board 4-RS232 Unit

27. Sensing Unit

28. Hardware (Power Supply Unit) Supplies +12V, -12V to Opamps Supplies +5V to MCU, RS232 and Signal Conditioning Unit Real Scenario

29. Hardware (Signal Conditioning Unit) Converts voltage and current’s range to 0-5V.

30. Hardware (MCU Board & RS232) MCU ADC (12 bits) unit performs the sampling and send them off to RS232 unit. RS232 unit sends data to the laptop.

31. PC Interface Unit

32. PC Interface Why we choose PC Interface Easy Accessibility Easy to use Faster calculation Database support available More functionality High compatibility with industry

33. PC Interface How to make a good Interface User’s need is the first thing we consider Structure Principle Simplicity Principle Feedback Principle Tolerance Principle Reuse Principle

34. PC Interface MDI (Multiple-document interface)

35. PC Interface RS232 and Wireless connection

36. PC Interface Main Monitor Panel

37. Software Implementation Communication via RS232(Serial Port) Communication via Xbee Discrete Fourier transform Inverse Discrete Fourier transform Plot Graphs

38. Results (From 2007 Similar Project)

39. Results (Watt Smart)

40. Possible Improvements Investigate and include the phase shift caused by circuit components. Voltage Regulation for all power supplies. Quality of voltage signal capture. Not base everything on Fluke power meter. An alternative way of measuring real power And the last and the most important: Continuous Research on Power Analysis!

41. Budget

42. Timeline

43. BusinessOpportunities Replace manual meter reading from utility companies. Introduce two-way communication with utilities companies Integration with home automation systems. 

44. ProblemsEncountered MCU replacement TI MSP430 MCU too complex to implement Insufficient information in data sheet Replaced with PIC MCU Wireless module Zigbee features not critical in project Higher costs for Zigbee Replaced with XBee module

45. Future Development • Home Automation • Control appliances from PC • Internet Connectivity • Remote monitoring/controlling • Data collection by Hydro companies • Business/Industrial monitoring

46. Great project • Great Team • Home electricity usage can be reduced • Goals met Conclusion

47. Questions?