Smart Grid Communications over Über-FiWi Networks


Motivation

The world as we know it entirely depends on oil. Since it is a limited resource, renewable energy resources will take a bigger place in our daily life also in order to be environmentally more sustainable.

The current electric grid is composed of the following main subsystems : generation, transmission, substation, distribution, and the consumer. Generators transmit high-voltage electricity over the transmission lines. Substations are connected to several distribution networks, where it connects a large number of consumers. Over the years, Supervisory Control and Data Acquisition (SCADA) systems were deployed to realize sophisticated supervisory systems such as the Energy Management System (EMS). Real-time data management systems called Remote Terminal Units (RTUs) were installed at substations and at generators. Typically, an RTU sends data about voltage, current, breaker status, and other power network parameters every 2 seconds. Several failed attempts have been made to extend the scope of this data flow to reach the consumer. Up to date, only experimental projects have been made. Current power utilities don’t have any visibility into distribution networks beyond substations, where most of the opportunities for energy efficiency and integration of distributed generation can be found.

Net electricity generation in OECD Europe (Trillion kilowatthours)
Fig. 1. Net electricity generation in OECD Europe (Trillion kilowatthours) [1].

The electric grid must change for several fundamental reasons. The upcoming exploitation of renewable energy resources such as photovoltaic and wind generators, where the energy produced depends on the climate and varies over time, has a big impact on the overall power generation. As depicted in Fig. 1, the electricity generation from renewable sources is expected to significantly increase over the next few years. Consequently, the electric grid will increasingly work with various types of heterogeneous generator. Meteorological conditions vary minute-by-minute. Also, energy storage systems such as batteries in plug-in electric vehicles (PEVs) add a new component to the overall power grid. Sophisticated two-way and end-to-end communications between all the power grid elements, including the consumer, must evolve to create a new power grid: the smart grid [2].

Smart grid: vision and anticipated benefits

According to [3], no consensus has been reached on what the term smart grid exactly means. At present, there are too many technologies for the first/last mile access and home area and it is unclear which of them will finally prevail as the smart grid communications technologies of choice. The vision of the future smart grid is all about equipping intelligent devices with communication interfaces and engaging customers to play an interactive role in order to reduce power consumption and shift demand to minimize peak loads, which is widely referred to as demand response. The smart grid is sometimes called the Energy Internet since its impact on our lifestyle and way of consuming and generating energy will be similar to how the Internet changed our way of communicating and sharing information.

The smart grid will be able to deliver not only energy but also information about every aspect of electricity generation and consumption bidirectionally, i.e., in both directions from and to each customer. The smart grid will be instrumental in addressing growing concerns about climate change and carbon gas emissions by exploiting renewable energy sources and controlling power consumption more efficiently, whereby homes will play a key role for the following reasons [4]:

  •     Over 50% of the generated electricity is currently consumed in homes.
  •     PEVs will be charged mostly at homes after returning from work.
  •     Homes will be the location of the largest number of distributed power generation devices, e.g., wind turbines and solar panels, also known as distributed energy resources (DERs).

Given the huge number of homes, smart grid solutions must be scalable and use low-cost and future-proof broadband access technologies. Different implementation and business models can be used to leverage on the benefits arising from the utilities’ right-of-way and possible infrastructure sharing. A conservative business model might follow the traditional concept of vertical integration, whereby the network owner, network operator, and service provider are the same entity. Vertical integration has been the model applied by the vast majority of incumbents for decades. By applying this model, a utility could exploit its right-of-way and would leverage on the security and maintenance benefits of a private network, but would face significant investments to provide full coverage in its service area. However, the future access network infrastructure business will be more divided in terms of ownership and operation, capitalizing on trust relationships between new alternative operators and incumbents. A promising approach to provide full coverage at reasonable costs is to jointly implement and share a common network infrastructure for both smart grid communications and broadband access, giving rise to what we refer to as the Über-FiWi network.

Research directions

Example Über-FiWi network connecting homes, PEVs, and DERs to the distribution management system (DMS)
Fig. 2. Example Über-FiWi network connecting homes, PEVs, and DERs to the distribution management system (DMS).

Broadband access networks
We currently witness that fibers are being pushed ever closer toward the home and end user. Optical fibers offer huge bandwidth capacity, longevity and low maintenance and observe a trend where coppers are replaced with optical fibers instead of coppers. Optical and wireless networks are complementary and will most likely coexist together as depicted in Fig. 2. Future broadband access networks will be hybrid combining the high capacity and longevity of optical fibers and the mobility and ubiquity of wireless networks [5].

Sensors
Advanced sensors will play a major role in the future smart grid [6]. At present, sensors are installed in power delivery systems and are limited to voltage and current for protection and control. Thus, the overall monitoring of the power grid is currently not possible. Sensors should be deployed in diverse terrain in order to control, monitor, and store fine-grained information about the overall power grid. There exist a lot of benefits of deploying sensors on a large scale such as safety to prevent risk of failure, maintenance to take action only when needed based on data from sensors, increase utilization depending on the condition of equipment, diagnostic analysis when events occur, adjust the power distribution in order to cope with intermittent renewable energy sources, etc. Thus, wireless and optical sensors will play a major role in the future smart grid, transforming FiWi networks into Fiber-Wireless Sensor Networks (Fi-WSNs).

Overview of the future smart grid
Fig. 3. Overview of the future smart grid [2].

The smart grid will be decomposed in 5 main components, as shown in Fig. 3: Applications used by operators, information management systems which regroup and model a huge quantity of data, FiWi networks enhanced with advanced sensor devices, and power systems.

Data flow
Several investigations have to be carried out concerning the nature of the data, rate, and quality attributes used by smart grid communications over Fi-WSNs.

Communications infrastructure
By now there is no consensus concerning the equipment and protocols that will be used to deliver data for the smart grid.

Quality-of-service (QoS)
Sensor components provide real-time information, which will use the same communications architecture used by several other applications.

Energy consumption
Optimizing the current power grid should be at least as effective concerning the energy consumption. The energy used by the communications infrastructure has to be limited.

Routing
Since there are several subsystems in the smart grids, efficient routing mechanisms in terms of utilization, end-to-end delay and throughput must be used.

Experimental system

Experimental Smart Grid System (ESGS) combines WattDepot, EcoWizard wireless sensors and enables to test custom algorithms for the Smart Grid over a real networking infrastructure. ESGS is written in Java.

Researchers

Advisors
  •    Prof. Martin Maier
  •    Prof. Geza Joos

Graduate Student
  •    Martin Lévesque

Publications

  •     R. Charni and M. Maier, “Total Cost of Ownership and Risk Analysis of Collaborative Implementation Models for Integrated Fiber-Wireless Smart Grid Communications Infrastructures,” IEEE Transactions on Smart Grid, vol. 5, no. 5, pp. 2264-2272, Sept. 2014.
  •     I. Harrabi and M. Maier, “Performance Analysis of a Real-Time Decentralized Algorithm for Coordinated PEV Charging at Home and Workplace with PV Solar Panel Integration,” Proc., IEEE Power & Energy Society General Meeting, National Harbor, MD, USA, July 2014.
  •     B. P. Bhattarai, B. Bak-Jensen, J. R. Pillai, and M. Maier, “Demand Flexibility from Residential Heat Pump,” Proc., IEEE Power & Energy Society General Meeting, National Harbor, MD, USA, July 2014.
  •     M. Lévesque and M. Maier, “Probabilistic Availability Quantification of PON and WiMAX Based FiWi Access Networks for Future Smart Grid Applications,” Proc., IEEE Transactions on Communications, vol. 62, no. 6, pp. 1958-1969, June 2014.
  •     M. Maier and M. Lévesque, “Dependable Fiber-Wireless (FiWi) Access Networks and Their Role in a Sustainable Third Industrial Revolution Economy (Invited Paper),” IEEE Transactions on Reliability, vol. 63, no. 2, pp. 386-400, June 2014.
  •     B. P. Bhattarai, B. Bak-Jensen, P. Mahat, J. R. Pillai, and M. Maier, “Hierarchical Control Architecture for Demand Response in Smart Grids,” Proc., IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC), Hong Kong, Dec. 2013.
  •     R. Charni and M. Maier, “Risk Analysis of Integrated Fiber-Wireless Smart Grid Communications Infrastructures Powered by Positive Energy Buildings,” Proc., IEEE/OSA/SPIE Asia Communications and Photonics (ACP), Beijing, China, Nov. 2013.
  •     M. Maier, “The Escape of Sisyphus or What “Post NG-PON2” Should Do for a Sustainable TIR Economy Apart from Neverending Capacity Upgrades (Invited Paper),” Optics, Special Issue of All Optical Networks for Communications, vol. 1., no. 1, pp. 47-66, March 2014.
  •     M. Maier, “FiWi Access Networks and the Golden Age: From Installation to Deployment in a Sustainable Third Industrial Revolution Economy (Invited Paper),” Proc., IEEE/OSA/SPIE Asia Communications and Photonics (ACP), Beijing, China, Nov. 2013.
  •     M. Maier, “From Co- Towards Multi-Simulation of Smart Grids and Their Role in a Sustainable Third Industrial Revolution Economy (Invited Talk),” Proc., SYTACom Annual Research Workshop, Montreal, QC, Canada, Oct. 2013.
  •     R. Charni and M. Maier, “Impact Study of Collaborative Implementation Models on Total Cost of Ownership of Integrated Fiber-Wireless Smart Grid Communications Infrastructures,” Proc., IEEE SmartGridComm, pp. 31-36, Vancouver, BC, Canada, Oct. 2013.
  •     I. Harrabi and M. Maier, “E-Mobility in Smart Microgrids: A New Research Area for Communications Networks,” Proc., IEEE Electrical Power and Energy Conference (EPEC), Halifax, NS, Canada, Aug. 2013.
  •     F. Aurzada, M. Lévesque, M. Maier, and M. Reisslein, “FiWi Access Networks Based on Next-Generation PON and Gigabit-Class WLAN Technologies: A Capacity and Delay Analysis,” IEEE/ACM Transactions on Networking, vol. 22, no. 4, pp. 1176-1189, Aug. 2014.
  •     S. Mansour, G. Joos, I. Harrabi, and M. Maier, “Co-Simulation of Real-Time Decentralized Vehicle/Grid (RT-DVG) Coordination Scheme for E-mobility within Nanogrids,” Proc., IEEE Electrical Power and Energy Conference (EPEC), pp. 1-6, Halifax, NS, Canada, Aug. 2013.
  •     D. Q. Xu, G. Joós, M. Lévesque, and M. Maier, “Integrated V2G, G2V, and Renewable Energy Sources Coordination over a Converged Fiber-Wireless Broadband Access Network,” IEEE Transactions on Smart Grid, vol. 4, no. 3, pp. 1381-1390, Sept. 2013.
  •     M. Maier, “Smart Grid Communications over Next-Generation PONs (Invited Paper),” Proc., Photonics North Conference, p. 1, Ottawa, ON, June 2013.
  •     M. Lévesque, M. Maier, F. Aurzada, and M. Reisslein, “Analytical Framework for the Capacity and Delay Evaluation of Next-Generation FiWi Network Routing Algorithms,” Proc., IEEE Wireless Communications and Networking Conference (WCNC), pp. 1926-1931, Shanghai, China, April 2013.
  •     M. Maier, “Reliable Fiber-Wireless Access Networks: Less an End than a Means to an End (Invited Paper),” Proc., International Conference on Design of Reliable Communication Networks (DRCN), pp. 119-130, Budapest, Hungary, March 2013.
  •     M. Lévesque, D. Q. Xu, G. Joós, and M. Maier, “Co-Simulation of PEV Coordination Schemes over a FiWi Smart Grid Communications Infrastructure,” Proc., IEEE IECON, pp. 2901-2906, Montréal, QC, Canada, Oct. 2012.
  •     M. Lévesque and M. Maier, “The Über-FiWi Network: QoS Guarantees for Triple-Play and Future Smart Grid Applications (Invited Paper),” Proc., International Conference on Transparent Optical Networks (ICTON), pp. 1-4, Coventry, United Kingdom, July 2012.
  •     M. Maier, “Advances and Future Trends for Convergence among Heterogeneous Wireless Systems (Invited Panel),” Proc., IEEE International Conference on Communications (ICC), Workshop on Convergence among Heterogeneous Wireless Systems in Future Internet, Ottawa, ON, Canada, June 2012.
  •     M. Maier, “Survivability Techniques for NG-PONs and FiWi Access Networks (Invited Paper),” Proc., IEEE International Conference on Communications (ICC), Workshop on New Trends in Optical Networks Survivability, Ottawa, ON, Canada, June 2012.
  •     X. Liu, L. Ivănescu, R. Kang, and M. Maier, “Real-time Household Load Priority Scheduling Algorithm based on Prediction of Renewable Source Availability,” IEEE Transactions on Consumer Electronics, vol. 58, no. 2, pp. 318-326, May 2012.
  •     M. Lévesque, M. Maier, Y. Desai, and G. Joos, “Adaptive Admission Control for a Smart Grid FiWi Communications Network facing Power Blackouts during a DDoS Attack,” Proc., IEEE Green Technologies Conference, pp. 1-3, Tulsa, OK, USA, April 2012.
  •     M. Maier, M. Lévesque, and L. Ivănescu, “NG-PONs 1&2 and Beyond: The Dawn of the Über-FiWi Network,” IEEE Network, Special Issue on Next Generation Optical Access Networks: Dynamic Bandwidth Allocation, Resource Use Optimization and QoS Improvements, vol. 26, no. 2, pp. 15-21, March/April 2012.
  •     M. Lévesque, D. Q. Xu, M. Maier, and G. Joos, “Communications and Power Distribution Network Co-Simulation for Multidisciplinary Smart Grid Experimentations,” Proc., SCS/ACM Spring Simulation Multiconference (SpringSim), Annual Simulation Symposium, pp. 1-7, Orlando, FL, USA, March 2012.
  •     M. Maier, “FiWi Access Networks: From Green to Smart Grid Communications Infrastructures (Invited Panel),” Proc., Colloque Annuel Réseau d'Informations Scientifiques du Québec (RISQ), Montreal, QC, Canada, Oct. 2011.
  •     M. Maier, “Fiber-Wireless Sensor Networks (Fi-WSNs) for Smart Grids (Invited Paper),” Proc., International Conference on Transparent Optical Networks (ICTON), Stockholm, Sweden, June 2011.

In the Media

  •     M. Maier, “Energie et si l'énergie fusionnait avec Internet?,” Interview in Badim 2020, France Telecom/Orange, June 2013.
  •     M. Maier, “Les réseaux optiques pourraient bouleverser notre rapport à l'énergie,” Agence Ecofin, March 2012.
  •     M. Maier, “Le jour où l’internet sera un fil conducteur de l’électricité,” TP Express, vol. 4, no. 7, Nov. 2011.
  •     M. Maier, “Le jour où l’internet sera un fil conducteur de l’électricité,” Interview in Planète INRS, Nov. 2011.

References

[1]
 U.S. Energy Information Administration, “The International Energy Outlook 2010,” U.S. Department of Energy, July 2010 (www.eia.gov/oiaf/ieo).
[2]
 P. P. Varaiya, F. F. Wu, and J. W. Bialek, “Smart Operation of Smart Grid: Risk Limiting Dispatch,” Proceedings of the IEEE, vol. 99, no. 1, pp. 40-56, Jan. 2011.
[3]
 S. Davies, “Grid looks to smart solutions,” IET Engineering & Technology, vol. 5, no. 7, pp. 49–51, May 2010.
[4]
 B. Heile, “Smart Grids for Green Communications,” IEEE Wireless Communications, vol. 17, no. 3, pp. 4–6, Jun. 2010.
[5]
 M. Maier, N. Ghazisaidi, and M. Reisslein, “The Audacity of Fiber-Wireless (FiWi) Networks (Invited Paper),” Proc. ICST ACCESSNETS, pp. 1-10, Las Vegas, NV, USA, Oct. 2008.
[6]
 A. Phillips, “Staying in Shape,” IEEE Power & Energy Magazine, vol. 8, no. 2, pp. 27-33, March/April 2010.