By Roy Kok, Kepware
There are several smart grid initiatives including home-to-grid (H2G), building-to-grid (B2G) and industry-to-grid (I2G). These all require varying levels of connectivity, either through new protocols or by leveraging legacy protocols and products.
1. Wireless communications with smart meters. Several phases lead to the new world of the smart grid. We are in one of the earliest phases, an instrumentation phase adding the ability to assess power use in real time. The majority of stimulus money earmarked for the smart grid is being used to enhance power monitoring with smart meters that can be read remotely and in real time. This requires enhanced communications. While there is no single smart grid protocol, there are ranges of protocols that can and are applied to smart grid applications. For a list of protocols being highlighted for smart grid use, see the “NIST Framework and Roadmap for Smart Grid Interoperability.” The world of smart grid communications likely will break down into two major categories, the consumer (home) and the industrial (building and industry) markets. These markets will be served through different technologies because of their needs and the costs involved. The consumer marketplace will be served through a combination of smart meter gateways, Internet interfaces and appliances designed to operate intelligently based on homeowner preferences or remote utility commands. These systems need to remain as inexpensive as possible for mass adoption. They need to connect simply, avoiding installation costs. They likely will make extensive use of wireless technologies such as ZigBee.
Smart Grid Software Solution for Interoperability
2. Industry to grid interface for legacy systems. Industrial applications have different requirements. They require the coordination of existing automation
systems. They require interfaces to legacy systems through a range of existing protocols. They also require a higher level of interaction, real-time communications enabling business-to-business communications for automation. The communications in the industrial market will be for demand response (DR) purposes. These controls will manage the shedding of loads to manage power availability as well as the remote control of auxiliary generation to augment power production. The I2G space will require an I2G industrial gateway, bridging internal systems and communication protocols for external access by a coordinating authority (the power utility or a power management authority).
3. Security in the I2G space. While security is important in both scenarios, it will be a critical requirement in the I2G space where controls can manage large loads. The compromise of one connection will have a major impact. Many of the legacy protocols were developed prior to our current cyberworld and are not suitable for an Internet-based communications architecture.
4. OPC protocol for data interoperability. One protocol in particular will be worth watching as the smart grid architectures unfold. The automation marketplace has developed standards for software interoperability as early as 1996. This standard is called OPC and is managed through the OPC Foundation. The foundation is supported by more than 400 member companies and, at this time, all major automation software products support OPC as their data interoperability standard. In 2006, the OPC Foundation began the specification of its next generation of technology, named OPC UA, short for OPC Unified Architecture, delivering support for the latest technologies and unifying the earlier specifications that were developed for different forms of information; OPC DA for data access, OPC AE for alarms and events and OPC HDA for historic data access.
OPC UA delivers technology that directly targets the features and benefits required in smart grid applications. These include platform portability (the ability to add OPC UA interoperability to all manners of system from field devices to central control systems), standards-based security (RSA data encryption and x509 certificates for connection authentication), and the support for all forms of data including complex objects (collections of data based on proprietary vendor standards or industry standards such as ISA-95). Ratified in 2009 by the OPC Foundation TAC, short for Technical Advisory Committee, OPC UA products are already in the market with many more under development.
5. Best-in-class protocols. The widespread installation of smart grid solutions at competitive prices will require support from many solution providers with competing solutions. Settling on the best-in-class protocols for interoperability, however, will be a benefit to enabling solutions to interoperate. Gateway solutions, converting one protocol to another, are already available to deliver interoperability to disparate systems.
OPC Foundation site: http://opcfoundation.org
Roy Kok is vice president of sales and marketing with Kepware. Visit http://kepware.com for more information.