1. Applications of Wireless Sensor Networks in Smart Grid Presented by Zhongming Zheng

2. Outline Introduction System Model OREM iHEM Application Performance evaluation

3. Introduction Smart grid – Modern electric power-grid infrastructure – For improving efficiency, reliability and safety – With integration of renewable and alternative energy sources – Through automated control and modern communication technologies

4. Introduction The key factor – Online power system condition monitoring, diagnostic, and protection – Reliable and online information – Avoid power disturbances and outages due to equipment failures, capacity limitations, natural accidents and catastrophes

5. Introduction Possible Solutions – Traditional wired monitoring systems Expensive communication cable installations Expensive regularly maintenance Not widely implemented today due to high cost

6. Introduction Possible Solutions – Wireless sensor networks Rapid deployment Low cost Flexibility Aggregated intelligence via parallel processing

7. Introduction Existing and potential applications of WSNs on smart grid – Wireless automatic meter reading – Remote system monitoring and equipment fault diagnostic

8. Introduction Wireless automatic meter reading – Reduce electric utility operational costs (No need for human readers) – Online pricing based on online energy consumption of the customers – Asset protection through advanced remote monitoring – WSNs provide low-cost and low-power solution

9. Introduction Remote system monitoring and equipment fault diagnostic – Avoid or largely alleviated power-grid and facility breakdowns – Existing remote sensing, monitoring and fault diagnostic solutions are too expensive – WSNs provide cost-effective sensing and communication solution in a remote and online manner

10. Introduction Challenges to apply WSNs in smart grid – Harsh environmental conditions – Reliability and latency requirements – Packet errors and variable link capacity – Resource constraints

11. Overview Previous work – Propose an in-home energy management application – Employ a wireless sensor home area network – Exploit communications among the appliances and an energy management unit This work – Develop the optimization-based residential energy management scheme – Aim to minimize the energy expenses of the consumers – Schedule appliances to less expensive hours according to the time of use tariff

12. Outline Introduction System Model OREM iHEM Application Performance evaluation

13. System Model System Configuration – Home area network – Utilize Zigbee protocol – Divide one day into equal-length timeslots – Various timeslots may have different price

14. Outline Introduction System Model OREM iHEM Application Performance evaluation

15. Optimization-Based Residential Energy Management (OREM) The consumer requests are given in advance Objective function – Minimize the total energy expenses

16. Optimization-Based Residential Energy Management (OREM) Constraints – the total duration of the cycles of the scheduled appliances does not exceed the length of the timeslot that is assigned for them

17. Optimization-Based Residential Energy Management (OREM) Constraints – A cycle may start at the end of one timeslot and it will naturally continue in the consecutive timeslot. – An appliance cycle is fully accommodated without experiencing any interruptions

18. Optimization-Based Residential Energy Management (OREM) Constraints – Bound the maximum delay to two timeslots to reduce consumer discomfort and to avoid bursts of request

19. Outline Introduction System Model OREM iHEM Application Performance evaluation

20. In-Home Energy Management(iHEM) Consumer demands are processed in real time Objective – Decrease the cost of energy usage at home – Minimize the comfort degradation for the consumers

21. In-Home Energy Management(iHEM) Scenario

22. In-Home Energy Management(iHEM) Notations – RFD: reduced function device. – FFD: full function device – PAN(Grey node): personal area network coordinator

23. In-Home Energy Management(iHEM) Check price & Scheduling

24. In-Home Energy Management(iHEM) START-REQ (a) – Request to start AVAIL-REQ (b) – Request for the availability of energy UPDATE-AVAIL (c) – Update the amount of available energy on the unit

25. In-Home Energy Management(iHEM)

26. Personal area network coordinator – Beacon-enabled mode Define the duty cycle with the superframe duration of the superframe structure Synchronize the nodes in the network Nodes only communicate in the active period In Contention Access Period, transmit data by CSMA/CA

27. Outline Introduction System Model OREM iHEM Application Performance evaluation Conclusion

28. Simulation Results

30. Q & A