Protocols Driving Smart Grid Interoperability

 

By Tony Paine, Kepware Technologies

Efforts are underway to create a smarter grid by adding intelligence to the electrical infrastructure. According to calculations by the U.S. Department of Energy (DOE), the electrical grid consists of 10,000 generating units with a generation capacity in excess of 1 million MW and more than 300,000 miles of transmission lines. With a growing environmentally conscious population and an increasing demand for energy, this infrastructure should be revamped.

Upgrades, the Energy Future

The keyword is revamp. With 100 years invested, utility companies and technology providers will reuse as much existing infrastructure as possible. Completed upgrade cost estimates are in the trillions of dollars and could be more expensive if the upgrade required replacement of existing generation plants and distribution facilities. Additionally, consumers will not want to tear down buildings and homes to take advantage of the smart grid. Because it is impractical to start from the beginning and create a single standard or protocol to unify the elements of this ecosystem, we must retrofit preexisting systems to provide smarter information.

The first step in creating a smarter grid was investing in an advanced metering infrastructure (AMI). An AMI contains a smart meter that enables near real-time two-way communications to the distributor. This technology enables utility companies to monitor energy usage in hourly intervals, which provides billing information based on consumption. This technology also enables consumers to determine the price of energy at any point in time. Before smart meters, readings were done manually, and consumers were charged a fixed rate regardless of when the energy was consumed. Consumers’ smart meter opinions likely depend on when and how much power the consumers utilize.

Smart meters are more than billing machines, however. They also have the ability to report power outages and quality of service. Such an exchange of information between utility companies and consumers is impossible without protocols, which define the structure and transfer of information between entities.

At first, these protocols were proprietary and forced utility companies to standardize on a brand of equipment to install from central system to consumer end point. A shift is currently underway, however, to utilize open protocols that provide interoperability between different vendors. The Internet protocol suite (which consists of protocols used over the Internet) is globally accepted and will be the foundation for communications. Internet protocols only provide lower-level communications interoperability at the network and transport layers. This allows vendors to select standardized components (such as Ethernet or Wi-Fi) to incorporate. These components can then be plugged into an existing, connected infrastructure in the smart grid ecosystem. Systems and devices must build their application-level requirements on top of these components, specifying data and corresponding structure to exchange.

The practice of creating application-level protocol requirements is not new to the power and building automation space.

The power industry also has its share of protocols that are utilized for interoperability. In North America, Distributed Network Protocol 3 (DNP3) is used frequently in process automation for electric utilities. DNP3 is built on top of the Internet protocols and supports two-way communications for control centers, remote terminal units (RTUs) and intelligent electronic devices (IEDs). DNP3 defines the security model for proper message authentication and encryption between end points. In Europe, the IEC 61850 protocol has been adopted and has similar DNP3 functionality and characteristics. Although there are other protocols for electric systems, these two technologies are well-established and will be considered when integrating existing infrastructure with tomorrow’s grid.

Beyond Protocols

Existing protocols also are present in the building automation and control networks space. One such standard is BACnet, which is widely used in heating, ventilating and air conditioning (HVAC) systems and lighting, security and fire detection applications. This protocol also supports two-way communications systems, has built-in discovery capabilities that provide plug-and-play capabilities and defines a user security model with message authentication and encryption. In order to create a smarter building, the existing control and automation systems must interoperate with the smart grid.

Manufacturers are large consumers of energy: A typical manufacturing process runs continuously. The manufacturing process has been automated for years in order to eliminate human error and produce quality goods within a short timeframe. A typical facility usually consists of many sub-systems and parts, not all of which are procured from the same vendor. In order to automate the manufacturing process, components must communicate. As within a smart grid, each component utilizes its own protocol–sometimes open, sometimes proprietary. In order to achieve interoperability, the manufacturing industry collaborated on the Open Connectivity (OPC) standard. OPC is an abstraction layer between the different components and their underlying protocols. The latest version of OPC is known as OPC Unified Architecture (UA), and provides some of the same features as the smart grid. UA is built on top of the Internet protocols and provides secure, reliable two-way communications between end points. OPC and UA are vital for industrial automation: Application-based gateways transform OPC requests into the appropriate underlying device-level protocols. This technology allows proprietary-based systems to be retrofitted into an open-based system, enabling all parties to communicate, share data and make intelligent, real-time decisions.

Given our dependence on power, security requirements must be considered during smart grid development. Security needs to be built into the communications infrastructure to protect against cyber attacks. The National Institute of Standards and Technology (NIST) leads the way in defining security requirements. NIST developed guidelines for security, risk assessment, privacy protection and prevention that must be adhered to by utility and technology providers. Any protocols selected for standardization will be compared to these guidelines before the protocols are considered.

It stands to reason that the power, building and manufacturing markets’ standards and protocols will be evaluated closely with smart grid development. All three of these spaces constitute a large piece of the smart grid ecosystem, whether through generation, distribution, transmission or consumption. Leveraging these protocols will accelerate creation and adoption while reducing costs and reusing proven technology.

Tony Paine is Kepware Technologies’ president and CEO.

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