ITU-T Focus Group on Smart Grid (FG Smart) was established by ITU-T TSAG agreement at its meeting in Geneva, 8-11 February 2010. The FG Smart will collaborate with worldwide smart grid communities (e.g., research institutes, forums, academia) including other SDOs and consortia.
ITU-T FG Smart has had seven meetings. The most recent one was in Jeju, Korea, 8-15 June 2011 At that meeting, FG Smart progressed a “deliverable document” which describes the architecture for smart grid. The document is based on NIST’s conceptual model [Publication 1108, NIST Framework and Roadmap for Smart Grid Interoperability Standards, Release 1.0, January, 2010] as a starting point of consideration.
Five domains are defined:
- Grid domain (bulk generation, distribution and transmission)
- Smart metering (AMI)
- Customer domain (smart appliances, electric vehicles, premises networks (HAN, BAN, IAN))
- Communication network(s)
- Service provider domain (markets, operators, service providers).
These five domains are viewed in three planes: the Service/Applications plane, the Communication plane, and the Energy plane. But the document does not say much about relevant Communications Technologies:
Several different communication technologies (listed below) could be used as the links between nodes in Home Area Network (HAN), Neighborhood Area Network (NAN), and Wide Area Network (WAN). How those technologies are to be used depends on many factors, such as performance, ease of implementation, and availability. Here’s a short list of a few candidate network technologies:
-3rd Generation Secure Radio systems within the IMT-2000 family
-4th Generation Secure Radio systems within the IMT-Advanced family
-Wireless Local Area Networks specified in IEEE 802.11
-Wireless Personal Area Networks, such as Bluetooth and Zigbee specified in IEEE 802.15
-WiMax specified by IEEE 802.16
-Short distance wireless communication, such as infrared communication
-IEEE 802.3 Ethernet – mamy variants are possible for smart grid use.
-PLC specified in various standard bodies, such as ITU-T G.9960/9961 (G.hn), G.9955/9956 (G.hnem), and IEEE 1901/1901.2
-Technology over coaxial cable, such as DOCSIS (Data Over Cable Service Interface Specifications), G.9954 (HomePNA), and G.9960/9961 (G.hn)
-Technologies over copper cable specified in ITU-T G.992 series, G.993 series (xDSL)
-Technologies over fiber cable specified in various standard bodies, such as ITU-T G.983 series (B-PON), G.984 series (G-PON), G.987 series (XG-PON), G.985/G.986 (point-to-point Ethernet based optical access system), IEEE 802.3ah (GE PON), and IEEE 802.3av (10GE PON)
ITU-T Editor’s Note: The actual physical mediums and communication technologies available for smart grid networks have not been selected or specified yet. There is a need to consider: Medium: fiber, Ethernet cable (twisted pair) coaxial, powerline, wireless – 3G, 4G, satellite, WiFi, WiMax, short distance; NGN (protocol or medium).
Aurhor’s Note: The individual subnetworks used for grid communications are very losely defined as HAN, NAN and WAN.
Fig.1. Simplified Smart Grid Domain Model in ICT Perspective
Figure 1 shows five interfaces across the planes and between domains, marked with numbers in circles. These are places where communications and exchange of information between the Communication network and other four domains, and between smart metering domain and customer domain take place. They are the focal of standards specifications and thus are called Reference Points.
Smart Grid Applications:
There are several representative applications for smart grid, including energy distribution, renewable energy management and storage, electric vehicles-to-grid, grid monitoring and load management, and smart metering. There is a particular focus on the smart metering and load management,because those two fundamental applications have the most interaction in the ICT area. This covers functions commonly called the Advanced Metering Infrastructure (AMI) plus additional functions to support Powered Electric Vehicle (PEV) charging and energy generations in the End-User domain.
Network Functions for Smart Metering and Load Control:
-Metering Networks: It provides connectivity for meters in a small geographical area, and data aggregation for meter readings in the area, and connectivity for End-User
Functions in homes or buildings through Gateway functions.
-Core Network/Transport: It provides connectivity over a wide geographical area, concentrating meter reading information from Neighbourhood Area Networks. It provides back-haul of data to the Applications Functions and Energy Control Functions.
Author’s Note: This document endeavors to compare the ITU-T FG-Smart Grid and IEEE P2030 architectures in a Table which has not been finalized yet.
IEEE P2030 provides guidelines for smart grid interoperability. “This guide provides a knowledge base addressing terminology, characteristics, functional performance and evaluation criteria, and the application of engineering principles for smart grid interoperability of the electric power system with end-use applications and loads”
Closing Comment: It remains to be seen whether this FG Smart Grid Architecture draft recommendation or any other Smart Grid standard will clearly define the specific network technology for HAN, AMI network, NAN (including outdoor mesh wireless), WAN (including fiber optic).