Monitoring of the Smart Grid An Overview

1. Monitoring of the Smart GridAn Overview Yee Wei Law

2. Introduction to the Grid Australian Standard: AS 60038-2000 “Standard voltages”: Transmission EHV: 275kV, 330kV, 500 kV HV: 220kV MV: 66kV Distribution LV: 11kV, 22kV

3. Outline • Why and what is the Smart Grid? • Three Smart Grid components • Transmission: Wide-area Monitoring System • Distribution: Distribution Automation • Consumption: Demand Response • Research Areas • Conclusion

4. What is the Smart Grid • Smart grid = envisioned next-gen power grid that is: Motivating (demand response) Accommo-dating (renewable energy) Intelligent (senses overload, rerouting) Quality-focused (minimum disturbances, interruptions) “Green” (minimal environmental impact) Efficient (meets demand without more cost) Resilient (to attacks, disasters)

5. Why the Smart Grid? • Ageing hardware + population growth = equipment at limits • Market deregulation (‘80s-‘90s) • Climate change • Distributed generation using renewable energy sources • Global cooperation (International Smart Grid Action Network including Australia) Cost of outages in USA in 2002: $79B

6. Why WAMS? • 8-10% energy lost in transmission and distribution networks • Energy Management System (EMS): control generation, aggregation, power dispatch • EMS computes optimal power flow • However, SCADA-based EMS gives incomplete view of system steady state (resolution: several seconds)

7. Phasor Measurement Units (PMUs) • Aka synchrophasors, because time-synchronized using GPS • Measures voltage and current phasors • Typically 30 time-stamped samples per sec • Control of electromechanical oscillation, voltage, frequency etc. Phadke and Thorp’s prototype circa 1988 Macrodyne’s 1690 MiCOM P847 ABB’s RES521

8. Generic architecture of the WAMS

9. Why Distribution Automation (DA)? • Remotely and efficiently identify and resolve system problems • Enables load shifting, alleviates overload conditions • Reconfigures the system after disturbances or interruptions • Facilitates coordination with customer services such as time-of-use pricing, load management and DERs • Maintain equipment health Substation Control center Distribution network

10. Advanced Distribution Automation • EPRI proposed advanced DA – complete automation of controllable equipment (actuators and sensors) • Sample actuators: • Auto-recloser: circuit breaker that re-closes after interrupting short-circuit current • Voltage regulator: usually at the supply end, but also near customers with heavy load • Switched capacitor bank: switched in when load is heavy, switched out when otherwise Switched capacitor bank Voltage regulator Recloser

11. DA: sensors • Static sensors: • Non-static sensors: Metal insulated semiconducting (MIS) sensor for detecting hydrogen RF leakage current sensor RF temperature sensor Aerial photography (SP AusNet): • Developed by Tokyo-based HiBot • Able to navigate around obstacle • Laser-based sensors • HD camera • Cost & energy is a constraint

12. DA: communication • EPRI identified two critical technologies: • Open communication architecture • Redeveloped power system for component interoperability • Urban networks: fiber opticsRural networks: wireless

13. Wireless comm technologies for DA Jemena, United Energy, Citipower and Powercor SP AusNet and Energy Australia * Note: ZigBee is not in here

14. Open mesh network standards • Edge over ZigBee: RF better penetration of steel structures, energy-efficient, bettersecurity • Notable vendor: Dust Networks 6LowPAN (RFC4919, RFC4944 etc.) • IPv6 for low-power wireless personal area networks • Edge over ZigBee: interoperability with existing IP-based devices • Routing protocol still being standardized by the ROLL working group (Routing Over Low power and Lossy networks)

15. Demand Response • Keep demand curve as flat as possible (especially during summers and winters) • Ideally, everyone uses high-efficiency appliances • Motivate consumers to shift their usage to off-peak hours

16. Demand Response programs • Price-based programs • Dynamic peak pricing / critical peak pricing: customers notified in advance of critical peak times (at most several days per year) DPP = Dynamic Peak Pricing Source: Energy Market Consulting associates, “A Report to the Ministerial Council on Energy”, 2009

17. Demand Response programs • Price-based programs • Time-of-use pricing: different tariffs for different hours of the day Available from some vendors at limited locations, for example:

18. Demand Response programs • Incentive-based programs • Direct load control (e.g. Australian water heaters) • Interruptible/curtailable service: reduce load during contingencies • Demand bidding, emergency demand response, capacity market, ancillary services market etc. • Reference: US Department of Energy, “Benefits of Demand Response in Electricity Markets and Recommendations for Achieving them,” report to the United States Congress, February 2006. • Enabling technology: smart meter and Advanced Metering Infrastructure

19. Smart Meter and Advanced Metering Infrastructure (AMI) Neighborhood Area Network Smart meter Home Area Network AMI

20. Smart Meter and Home Area Network • In VIC, official rollout will run from 2009 to 2013 • Smart meters • To send meter data every 30 minutes • To enable remote connection/disconnection • To detect outage • To support demand response • Provide information via in-home display • Provide input to smart appliances via Home Area Network (ZigBee for Australia) • Fast charging Plug-in Hybrid Electric Vehicles (PHEV) introduce harmful harmonics – smart meters will help [Masoum et al., 2010]

21. Some research areas Transmission • PMU placement problem • Low-cost transmission line monitoring Distribution • Distribution network reconfiguration • Multi-objective optimization problem: minimize real losses, regulate voltage profile, load-balancing • Resilient wireless sensor network for substation monitoring and distribution automation • Coordination of load management and demand response Overall • Security

22. Conclusion • Advances in sensor and comm. tech driving Smart Grid • Grid modernization stimulates multi-disciplinary research • In progress: • $100m Smart Grid, Smart City demo project in Newscastle • Intelligent Grid: CSIRO and five universities • Collaboration opportunities sought

23. Select references • EPRI, “Sensor Technologies for a Smart Transmission System,” white paper, Dec 2009. • V. Gungor and F. Lambert, “A survey on communication networks for electric system automation,” Computer Networks, vol. 50, no. 7, pp. 877 – 897, 2006. • Y. Liu et al., “False data injection attacks against state estimation in electric power grids,” Proc. 16th ACM Computer and Communications Security, 2009. • M. Masoum, P. Moses, and S. Deilami, “Load management in smart grids considering harmonic distortion and transformer derating,” in Innovative Smart Grid Technologies (ISGT), 2010,pp. 1 –7. • B.K. Panigrahi et al., “Computational Intelligence in Power Engineering”, Springer-Verlag Berlin Heidelberg, 2010.

24. Smart Grid components • Generation • Distributed generation • Microgrid • Transmission • Wide-area monitoring system (WAMS) • Distribution • Distribution automation (DA) • Consumption • Demand response Advanced Metering Infrastructure (AMI)