Framework for Application Modeling
by Thierry Coste, EDF, and Laurent Guise and Mario Jardim, Schneider Electric
French utility giant EDF uses IEC 61850 for more than the standard's usual communication applications. Working with Schneider Electric, EDF has embraced a new approach for application modeling with IEC 61850 at its core.
For designing wind farms and photovoltaic (PV) systems, EDF employs this approach as early as the requirements-gathering level. The approach echoes one encouraged by Schneider Electric for using IEC 61850, an ambition the company translated into software engineering tools.
With its new approach to engineering smart substation automation systems, EDF places information flow at the center of project engineering.
Approach, Common Language
EDF prefers a data-driven approach in which information describes the system, and the system is built from those details-not from devices. The utility begins with system requirements and leaves device considerations for later-consequences of those requirements. After starting with the big picture, many groups iteratively contribute to this application reference model.
The language of that information is key. In the pursuit of smooth information flow and data transactions, EDF uses IEC 61850 and the XML-based Substation Configuration Language (SCL) it defines. The utility uses SCL to specify functional and operational requirements, describe installations and device capabilities, and communicate among engineering tools used throughout the process.
Any person or machine at EDF can read and understand that common language. The language enables information exchange among devices, people, departments, organizations, generations of stakeholders and the components and people involved in projects and systems.
To realize those benefits and place engineers in the most ergonomic environment possible, software developed by Schneider Electric aims to remain close to the language of the user while hiding as much SCL as possible.
Benefits to System Engineering
Strong, smart solution design ensures a clear picture of operational requirements, required functions and their dependencies. It also ensures a more secure, easily maintainable future for those solutions.
EDF finds this standards-based approach a more robust way to address problems. For example, start with gathering requirements. EDF's approach, based completely on the IEC 61850 standard, allows the capture of unambiguous requirements in a formal way.
As another example, when an existing device must be changed or a new device added, its purpose and place in the systems is not lost for future evolutions. That is, EDF does not need to rely on what a given device provides. Because EDF has the descriptions and knowledge of exactly what's required, it can answer that need with another suitable device. Replacement is always easier when the reference is retained, meaning EDF knows exactly which functions and flows of information are required to solve the problem.
The new approach also leads to timely project delivery. The standard-based modeling approach decreases lead times because less engineering time must be devoted to projects.
When gathering requirements to describe system automation and other processes, EDF's use of 61850 as an engineering tool also provides a more industrialized way to engineer and instantiate systems. At the modeling stage, the approach enables template creation-not templates of specific systems, as they include no device-specific details; rather, templates that can contain profiles about the system's purpose, what it requires and how it should perform. Such information can be relevant for many people because EDF can define many systems by instantiating a collection of well-defined templates.
With its investment in IEC 61850 engineering tools for specification and pre-engineering, Schneider Electric illustrates that IEC 61850 enables companies such as EDF to improve efficiency dramatically from very upstream project phases, capture knowledge in a sustained way, and spread such knowledge to all downstream steps of a smart system.
Benefits to Testing, Simulation
Testing also benefits from EDF's IEC 61850-based approach. System verification and validation follow with relative ease from the detailed definitions described in a common language by a specification. Members of the testing team don't require understanding of the entire system but only an understanding of the ideal outcome. Looking at how the system is expected to behave and not how it works internally or details of particular equipment frees EDF from requiring complete vendor system understanding.
The same is true for system simulation and extension purposes when that point in a project is reached. Using a common language to provide a complete, detailed system specification is useful for dynamic solution testing, as well as planning for modifications and upgrades.
Benefits to Corporate Intelligence
Sharing and reuse of EDF's system design information through a common language brings about better corporate intelligence. IEC 61850 can help transform this knowledge and data into formal descriptions, which then can be accessed and shared across an organization. For example, the creation of base reference models can fit the needs of engineering groups, operations or system integrators. Such sharable models have many opportunities for reuse when that information is exchanged across an organization.
EDF's IEC 61850-based approach also is used to capture and retain knowledge. Because the utility's large work force has substantial depth and breadth of knowledge but lacks immortality, the organization needs to capture and retain as much of that knowledge as possible while possible.
Benefits to Standardization, Open-vendor Solutions
EDF's application of this framework also helps it move toward the design of open-vendor or vendor-agnostic solutions. Such standardization is valuable to utilities. Much modernization, driven by many factors such as cybersecurity concerns and regulatory motivations, further fuel the pursuit of such systems.
The Road Behind and Ahead
EDF is moving toward formal specifications based on IEC 61850, which replace its current collections of Word documents. The first step is the creation of single-line diagrams, for which 61850 serves as the primary basis. Afterward, the organization can plug in smart functions. This is expected to help EDF integrate and manage connectivity between information technology (IT) and operations technology (OT) and harmonize their worldviews.
EDF prefers to focus first on its approach and refine tools later. In the meantime, it's about the capability of the methodology and its application. Implementation and tools that support interoperability and smart systems will follow. So the utility begins with a 61850 format for system specifications and uses that for configuration. The aim is to achieve a vertical approach, such that everyone using the data model also can use its associated suite of tools-one in which all actors use the same tools that rely on a methodology with all stages of information, which itself relies heavily upon Unified Modeling Language (UML).
Next, EDF intends to employ the SCL data model to cover the numerous components of its work. People work at many levels, such as with specifications or in control centers, and there exist various tasks whose completion could be aided by using the SCL object data model. Tools based on such a model can be used to specify and deploy systems and equipment.
SCL meets its boundary at the edge of the network, at the substation or feeder level, for example. But there exist many information systems that must increasingly communicate with one another about the network's needs. These include network monitoring, asset, outage and customer management systems, to name a few. EDF aims to integrate all of them systematically within its SCL-based suite of tools. Data provided by such systems can be brought in line with existing tools.
Existing tools deal with general automation, but EDF's perspective is to deploy 61850 everywhere. Every object connected to the control center should be connected according to 61850, including switches outside of the substation and more. When EDF needs to add new wind or PV to its network, for example, it must be able to connect them to the distribution system operator. To effectively operate and manage the network, the operator must be able to communicate, control and take measurements. Strong communication among power producers and the transmission network is highly desirable.
Schneider Electric shares EDF's vision for IEC 61850. To reach that goal, the company participates in IEC standardization. The company's engineering tools can import and manage namespaces specific to any domains where IEC 61850 is defined, and possibly user-specific namespace domains.
EDF wants to apply IEC 61850 principles toward a common language to model automation during the requirement phase, integrate IT and OT, and capture, transform and share network knowledge among all utility actors.
The goal is to reduce the complexity and time to engineer and deliver the networks on which everyone relies.
By adopting and extending a standard-based approach, EDF moves closer to interoperable, open-vendor solutions and many other benefits, such as power engineers' having more time and resources to pursue their real interest: power engineering.
Thierry Coste is a research engineer and project manager for electric automation systems for EDF R&D. He has a degree in electrical engineering and industrial computing and is a member of WG10 and WG17 of the International Electrotechnical Commission (IEC TC57).
Laurent Guise is a senior expert in automation systems for electric utilities at Schneider Electric. He has an engineering degree from Supélec (France) and is involved in smart grid standardization worldwide.
Mario Jardim is a senior offer manager in marketing at Schneider Electric. He has a degree in automation and control engineering and an executive MBA.