While the IEC 61850 substation communications standard has arrived in Europe and parts of the rest of the world as an “instant hit,” acceptance in North America has been more lukewarm. Early adopter utilities, some of whom have only recently changed over to “second generation” communications protocols such as DNP3, are concerned about the complexity and associated cost of deploying the next big step.
The truth is that IEC 61850 has the potential to significantly reduce the costs of planning, configuring and later upgrading a substation automation system.Papers have shown that using the IEC 61850 Part 6 Substation Configuration Language (SCL) standard file format and the self-description capability of the protocol can reduce the time required to set up a substation device - say, a protection relay- by 75% or more.
However, the key to achieving such benefits is the availability of tools that take advantage of these features of IEC 61850.So far, not many have done so.
Current Tools Take the First Steps
Development of IEC 61850 products has followed a fairly straightforward pattern.The first IEC 61850 devices to appear were fixed-function or specialized function devices, particularly protection relays and meters.
The first configuration tools to be developed therefore only had to select a few options to build a complete IEC 61850 object model.The user could choose, for instance, which protection elements to enable, and the configuration tool would use those few decisions to automatically build the complete set of IEC 61850 data the device would produce – hundreds or thousands of points of information.Or, more often, the IEC 61850 view of the device would be fixed, with no options at all.The sole purpose of the tool was to configure this one type of device.
Such an approach works fine for a specialized Intelligent Electronic Device (IED), but not so well for those devices that have to be more flexible.Devices such as substation user interfaces, data concentrators, protocol converters, substation computers, and logic controllers have to act as IEC 61850 clients, gathering data from dozens or even hundreds of Intelligent Electronic Devices (IEDs). They must read the data and map it to their internal databases; they may display the data or process it before passing it on.These clients need a view of all the data in the substation.
And IEC 61850 IEDs in the substation vary widely, just like their predecessors, and perhaps even more so.While IEC 61850 standardizes how data should be named and structured, the specification permits great variation in what data is actually reported by any device.Vendors are permitted to add or remove items as necessary to provide added value.This makes it more difficult to configure a client and a substation.
Perhaps, for this reason, there have so far been few IEC 61850 clients available, and correspondingly few system-level substation configuration tools for IEC 61850.The specification is well-suited for creating such tools; the standard SCL file format permits tools to store information about the electrical connectivity, communications network, number and type of devices, and of course the data reported by all the devices in the substation.
Nevertheless, most tools available configure only single devices or just those from that vendor.Those that do attempt to interconnect multiple devices tend to focus on a particular aspect of the protocol.For instance, high-speed peer-to-peer protection messaging, named Generic Object-Oriented Substation Events, or GOOSE, is a popular feature of IEC 61850.Therefore, some vendors have tools that permit the configuration of the GOOSE protocol between multiple devices.However, these tools do not configure any of the other IEC 61850 features.
Other tools have a different problem:they provide a system level view of the substation, but are intended to be planning tools and require a significant knowledge of IEC 61850.The language they use is the language of the protocol, not the power system engineer.For instance, the text string “MMXU3.PhV.phsA.cVal.mag.f” translates to “Magnitude expressed in floating-point format of the Phase-to-Ground Volts on Phase A, gathered by the Metering Measurement Unit connected to feeder 3.”However, a power engineer setting up a substation using the new tools for the first time cannot be expected to know that.It is a major breakthrough of IEC 61850 that the protocol can standardize and express such names, but tools need to speak the language of their primary users.
Even better, tools should speak graphically, not with text at all.Substation Configuration Language has the capability to represent simple substation one-line diagrams.Very few IEC 61850 tools yet make use of this powerful feature as a method for actually planning the substation, from the electrical equipment to the communications equipment down to the functions and thousands of data points.
The IEC 61850 tools that are available now are good at what they do – mostly configuring individual devices.However, they are missing much of the potential of IEC 61850.
Barriers to Evolution
So why have system-level configuration tools been slow to appear?One reason is that it is simply a lot of work.Like the window-based desktop used by today’s computers, IEC 61850 has the capability to “hide” the complexity of computing systems from the user and turn that complexity into a “point-and-click” experience.However, just like the Windows-based desktop, a significant amount of software must be written by the vendors in order to make that experience happen.As with desktop computing, complexity has been shifted away from the user and onto the developer.
IEC 61850 vendors have sensibly (and cost-effectively) chosen to break the problem into smaller products that can be released individually, rather than the “moon shot” approach of trying to do everything at once.For most, this means developing a single-device configuration tool, and then using it as a platform to build a system tool.
One major barrier to this evolution is the vendors’ installed product bases, which are mostly built around unstructured, points-list types of databases.Mapping structured IEC 61850 data models into this format without a lot of human intervention is a formidable task.
Another barrier is the fact that many IED vendors are not GUI developers.They are experts at high-performance, real-time embedded software and need to develop the capability to write sophisticated GUI software.Some have begun to do this through partnerships, others by buying the software.The larger vendors have managed this by leveraging expertise found in other divisions of their organization.Any of these efforts take more time.The first fruits of this “ramp-up” in GUI technology are only beginning to be seen.
What Will the Killer App Look Like?
In spite of the these barriers, we do not want to lose sight of our clear goal as an industry; a real top down design approach. In addition to supporting the IED centric configuration approach, the IEC 61850 Part 6 Standard has been written to support the top down approach starting with definition of the complete substation and power system functions.The starting point for configuration would be the station one-line with device ratings and power system functions followed by a definition of the associated automation functions.The potential system wide benefits for such a capability are very significant – in fact huge!
What utilities need to convince them of the usefulness of IEC 61850 is a tool that looks at the entire substation.Figure 1 illustrates how such a tool might be used. It would have the following characteristics:
Engineers involved in the development of IEC 61850 have been talking about this kind of tool for nearly a decade now, but the potential users of the standard have not been informed about how it could work.
The Future of IEC 61850 Rides on Ease of Use
It is instructive to observe the different approaches to substation automation taken in different parts of the world and the impacts on the adoption of new technologies such as IEC 61850.The lessons learned from this highlight the importance of investing in the next generation of user configuration tools.
In Europe and some international regions, there is a strong practice of following IEC standards.A significant amount of automation equipment is purchased as a component of a complete substation project procured from one vendor or substation integration contractor.This means that even though the protection and control devices support 61850, the difficulty in integrating the devices is mitigated.When these stations are expanded or upgraded the tendency is to go back to the original equipment provider.
In North America our view of standards in the communication protocol area is less rigorous and we prefer to be less reliant on our suppliers. While things have begun to change in the last few years, historically the support of a standard communication protocol was not a key determinant in the selection of a specific IED.This led to a proliferation of devices supporting different protocols.In addition the majority of protection equipment is purchased separately from the control equipment and installed on a retrofit basis.This has led to products from many vendors speaking a number of protocols in most substations.This has a number of significant impacts on the application of IEC 61850 in North America:
The effort to develop these tools will be well rewarded.Utilities implementing IEC 61850 are already seeing substantial benefits depending on the size and architecture of the system.Yet there remain larger potential benefits inherent with the protocol, object oriented and Ethernet LAN approaches as well as engineering process and SCL incorporated into IEC 61850. Some of these benefits include reductions in:
As mentioned above, savings in the device configuration area alone can approach 75 percent compared to the current effort with other protocols.In addition, the use of substation level configuration tools can bring further reductions in the other areas listed above – notably engineering, testing and commissioning.In combining these reductions, we should expect substantially lower life cycle costs of this protection and control equipment as we go forward.This is very possible as the capital cost of the equipment is typically less than 20 percent of the total installed cost with the other 80 percent coming from the scope where potential savings are large.Long term operations and maintenance savings and improvement in system reliability add to this overall benefit.
The Next Stage
Once more system-level IEC 61850 configuration tools are available, there are further steps that could be taken to integrate these substation tools with the rest of the power system.
Firstly, other protocols are developing standard configuration formats of their own.Chief among these is DNP3, which has more users than any other protocol among electrical utilities in North America.The DNP Users’ Group will soon be releasing a configuration file format that mirrors the paper Device Profile Document previously used to describe DNP device implementations.Although not as flexible as SCL, the current draft of this XML schema contains locations where IEC 61850 data attribute names could be stored.A system configuration tool that could make use of such links would speed up the creation of DNP3-to-IEC 61850 gateways.This would not only reduce the costs of substation integration, but would also help accelerate the acceptance of IEC 61850 in North America.
Secondly, there is a whole world of data communications in progress within the control center or “power system operations and maintenance” environment that has only just begun to reach out toward the substation.IEC working groups have begun to define how to harmonize the IEC 61850 standard with the IEC 61970 Common Information Model (CIM) and Generic Interface Definition (GID) specifications. Figure 2 illustrates one proposal for how this might occur using Web Ontology Language (OWL) to enable converters between SCL and CIM XML formats.
Such a harmonization between substation and control center environments might enable system-wide applications such as:
In this way, the next generation of IEC 61850 configuration tools may lead to something even bigger:the ability to build not just complete substations, but an intelligent power grid.
About the Authors
Grant Gilchrist, P.ENG. is a consulting engineer for EnerNex Corporation and a recognized expert in data communications for the electric power industry, particularly in areas relating to Internet protocols, OSI, security, and SCADA applications. He has been extensively involved in standards development for the IEC, IEEE, American Gas Association, Standards Council of Canada, and the DNP Technical Committee. Gilchrist was a key contributor to the EPRI IntelliGrid Architecture and Utility Communications Architecture. He has been actively involved in the development of the IEC 61850 series of utility communications standards, and a key contributor to the rollout and deployment of IEC 60870-5 protocols.
Ron Farquharson is a consultant in utility automation for EnerNex Corporation. He has over 25 years experience in substation control, automation, and monitoring. Farquharson spent the bulk of his career at GE/GE Harris/Harris/Westronic, where he held numerous positions in product management/ marketing and project management.He chaired the Task Force in the IEEE PES Substations Committee called "The Use of Computer Technology in Substation Data Acquisition and Control." He was also a key driver behind the DNP protocol development at Westronic and the decision to form the DNP User Group. He currently serves on the DistribuTECH Conference Advisory Committee.
The truth is that IEC 61850 has the potential to significantly reduce the costs of planning, configuring and later upgrading a substation automation system.Papers have shown that using the IEC 61850 Part 6 Substation Configuration Language (SCL) standard file format and the self-description capability of the protocol can reduce the time required to set up a substation device - say, a protection relay- by 75% or more.
However, the key to achieving such benefits is the availability of tools that take advantage of these features of IEC 61850.So far, not many have done so.
Current Tools Take the First Steps
Development of IEC 61850 products has followed a fairly straightforward pattern.The first IEC 61850 devices to appear were fixed-function or specialized function devices, particularly protection relays and meters.
The first configuration tools to be developed therefore only had to select a few options to build a complete IEC 61850 object model.The user could choose, for instance, which protection elements to enable, and the configuration tool would use those few decisions to automatically build the complete set of IEC 61850 data the device would produce – hundreds or thousands of points of information.Or, more often, the IEC 61850 view of the device would be fixed, with no options at all.The sole purpose of the tool was to configure this one type of device.
Such an approach works fine for a specialized Intelligent Electronic Device (IED), but not so well for those devices that have to be more flexible.Devices such as substation user interfaces, data concentrators, protocol converters, substation computers, and logic controllers have to act as IEC 61850 clients, gathering data from dozens or even hundreds of Intelligent Electronic Devices (IEDs). They must read the data and map it to their internal databases; they may display the data or process it before passing it on.These clients need a view of all the data in the substation.
And IEC 61850 IEDs in the substation vary widely, just like their predecessors, and perhaps even more so.While IEC 61850 standardizes how data should be named and structured, the specification permits great variation in what data is actually reported by any device.Vendors are permitted to add or remove items as necessary to provide added value.This makes it more difficult to configure a client and a substation.
Perhaps, for this reason, there have so far been few IEC 61850 clients available, and correspondingly few system-level substation configuration tools for IEC 61850.The specification is well-suited for creating such tools; the standard SCL file format permits tools to store information about the electrical connectivity, communications network, number and type of devices, and of course the data reported by all the devices in the substation.
Nevertheless, most tools available configure only single devices or just those from that vendor.Those that do attempt to interconnect multiple devices tend to focus on a particular aspect of the protocol.For instance, high-speed peer-to-peer protection messaging, named Generic Object-Oriented Substation Events, or GOOSE, is a popular feature of IEC 61850.Therefore, some vendors have tools that permit the configuration of the GOOSE protocol between multiple devices.However, these tools do not configure any of the other IEC 61850 features.
Other tools have a different problem:they provide a system level view of the substation, but are intended to be planning tools and require a significant knowledge of IEC 61850.The language they use is the language of the protocol, not the power system engineer.For instance, the text string “MMXU3.PhV.phsA.cVal.mag.f” translates to “Magnitude expressed in floating-point format of the Phase-to-Ground Volts on Phase A, gathered by the Metering Measurement Unit connected to feeder 3.”However, a power engineer setting up a substation using the new tools for the first time cannot be expected to know that.It is a major breakthrough of IEC 61850 that the protocol can standardize and express such names, but tools need to speak the language of their primary users.
Even better, tools should speak graphically, not with text at all.Substation Configuration Language has the capability to represent simple substation one-line diagrams.Very few IEC 61850 tools yet make use of this powerful feature as a method for actually planning the substation, from the electrical equipment to the communications equipment down to the functions and thousands of data points.
The IEC 61850 tools that are available now are good at what they do – mostly configuring individual devices.However, they are missing much of the potential of IEC 61850.
Barriers to Evolution
So why have system-level configuration tools been slow to appear?One reason is that it is simply a lot of work.Like the window-based desktop used by today’s computers, IEC 61850 has the capability to “hide” the complexity of computing systems from the user and turn that complexity into a “point-and-click” experience.However, just like the Windows-based desktop, a significant amount of software must be written by the vendors in order to make that experience happen.As with desktop computing, complexity has been shifted away from the user and onto the developer.
IEC 61850 vendors have sensibly (and cost-effectively) chosen to break the problem into smaller products that can be released individually, rather than the “moon shot” approach of trying to do everything at once.For most, this means developing a single-device configuration tool, and then using it as a platform to build a system tool.
One major barrier to this evolution is the vendors’ installed product bases, which are mostly built around unstructured, points-list types of databases.Mapping structured IEC 61850 data models into this format without a lot of human intervention is a formidable task.
Another barrier is the fact that many IED vendors are not GUI developers.They are experts at high-performance, real-time embedded software and need to develop the capability to write sophisticated GUI software.Some have begun to do this through partnerships, others by buying the software.The larger vendors have managed this by leveraging expertise found in other divisions of their organization.Any of these efforts take more time.The first fruits of this “ramp-up” in GUI technology are only beginning to be seen.
What Will the Killer App Look Like?
In spite of the these barriers, we do not want to lose sight of our clear goal as an industry; a real top down design approach. In addition to supporting the IED centric configuration approach, the IEC 61850 Part 6 Standard has been written to support the top down approach starting with definition of the complete substation and power system functions.The starting point for configuration would be the station one-line with device ratings and power system functions followed by a definition of the associated automation functions.The potential system wide benefits for such a capability are very significant – in fact huge!
What utilities need to convince them of the usefulness of IEC 61850 is a tool that looks at the entire substation.Figure 1 illustrates how such a tool might be used. It would have the following characteristics:
- Start with the users. Developers of successful PC software have learned that writing use cases, holding workshops, utilizing focus groups, taking surveys and other such requirements-gathering processes pay off. Just because the target user is an engineer is no excuse for making it hard to use.
- Design from the top down. A system level configuration tool that follows a progression starting with the definition of the complete substation, including the power system and protection functions, and adding the desired communications and automation functions will enable engineers to select the IEDs with the needed capabilities. This will help avoid the “take a shopping cart to the trade show” method of designing a substation. IEC 61850 is the first paradigm that permits users to choose functions first, rather than devices.
- Design the whole substation.Such a tool must not focus on a single device, but permit an engineer to start with a one-line diagram for the substation, add functions, and then map those functions to devices.To continue the progression stated above, the System Level (Substation) Configuration Tool of the future should allow the engineer to acquire the IED Capability Description (ICD) files from the new IEDs, drag-n-drop the functions they have already defined onto the IEDs, and then generate a Configured IED Description (CID) file that the IED level configuration tool would use.
- Design the whole protocol.IEC 61850’s potential will not be realized through only one feature or set of features.Having multiple smaller tools that configure different aspects of the protocol is a valid design methodology, but to be easy to use, they must work together.
- Work seamlessly with other tools. Figure 1 shows how SCL is intended to serve as a common language for either transferring data between tools, or for transferring configurations directly with devices such as the data concentrator and GUI in the figure. At the moment, there is no standard transport mechanism or service interface defined for exchanging SCL files.System tools must therefore take the initiative to launch other vendors’ tools or to select custom directories where SCL files could be placed.
- Use human language.As discussed earlier in this article, IEC 61850 names, while standardized, are not easy to use.
- Use current GUI technology.The power industry is a small market, and therefore vendors do not have the same resources the desktop computing industry has for designing user-friendly software.However, that doesn’t mean that power industry software has to look like freeware.A key feature often mentioned wistfully by users is the ability to create “templates” of IEDs that can be dragged onto a working area and then customized.Not all configuration tools support this rather basic capability.
Engineers involved in the development of IEC 61850 have been talking about this kind of tool for nearly a decade now, but the potential users of the standard have not been informed about how it could work.
The Future of IEC 61850 Rides on Ease of Use
It is instructive to observe the different approaches to substation automation taken in different parts of the world and the impacts on the adoption of new technologies such as IEC 61850.The lessons learned from this highlight the importance of investing in the next generation of user configuration tools.
In Europe and some international regions, there is a strong practice of following IEC standards.A significant amount of automation equipment is purchased as a component of a complete substation project procured from one vendor or substation integration contractor.This means that even though the protection and control devices support 61850, the difficulty in integrating the devices is mitigated.When these stations are expanded or upgraded the tendency is to go back to the original equipment provider.
In North America our view of standards in the communication protocol area is less rigorous and we prefer to be less reliant on our suppliers. While things have begun to change in the last few years, historically the support of a standard communication protocol was not a key determinant in the selection of a specific IED.This led to a proliferation of devices supporting different protocols.In addition the majority of protection equipment is purchased separately from the control equipment and installed on a retrofit basis.This has led to products from many vendors speaking a number of protocols in most substations.This has a number of significant impacts on the application of IEC 61850 in North America:
- Easy to use configuration tools for IEDs are essential
- IED Data Concentrators or Gateways supporting IEC 61850 Client & Server implementations are needed to connect the legacy IEDs onto the Substation Network (Station LAN).
- Strong focus on the development of easy to use configuration tools is needed for the IED Data Concentrators.
- Efforts to define common methods and tools between 61850 and popular current protocols such as DNP are important (see “Next Stage” section).
The effort to develop these tools will be well rewarded.Utilities implementing IEC 61850 are already seeing substantial benefits depending on the size and architecture of the system.Yet there remain larger potential benefits inherent with the protocol, object oriented and Ethernet LAN approaches as well as engineering process and SCL incorporated into IEC 61850. Some of these benefits include reductions in:
- Initial engineering and design
- Ease of configuration
- Installation/wiring and testing
- Commissioning
- Effort for future upgrades
- Staff training
As mentioned above, savings in the device configuration area alone can approach 75 percent compared to the current effort with other protocols.In addition, the use of substation level configuration tools can bring further reductions in the other areas listed above – notably engineering, testing and commissioning.In combining these reductions, we should expect substantially lower life cycle costs of this protection and control equipment as we go forward.This is very possible as the capital cost of the equipment is typically less than 20 percent of the total installed cost with the other 80 percent coming from the scope where potential savings are large.Long term operations and maintenance savings and improvement in system reliability add to this overall benefit.
The Next Stage
Once more system-level IEC 61850 configuration tools are available, there are further steps that could be taken to integrate these substation tools with the rest of the power system.
Firstly, other protocols are developing standard configuration formats of their own.Chief among these is DNP3, which has more users than any other protocol among electrical utilities in North America.The DNP Users’ Group will soon be releasing a configuration file format that mirrors the paper Device Profile Document previously used to describe DNP device implementations.Although not as flexible as SCL, the current draft of this XML schema contains locations where IEC 61850 data attribute names could be stored.A system configuration tool that could make use of such links would speed up the creation of DNP3-to-IEC 61850 gateways.This would not only reduce the costs of substation integration, but would also help accelerate the acceptance of IEC 61850 in North America.
Secondly, there is a whole world of data communications in progress within the control center or “power system operations and maintenance” environment that has only just begun to reach out toward the substation.IEC working groups have begun to define how to harmonize the IEC 61850 standard with the IEC 61970 Common Information Model (CIM) and Generic Interface Definition (GID) specifications. Figure 2 illustrates one proposal for how this might occur using Web Ontology Language (OWL) to enable converters between SCL and CIM XML formats.
Such a harmonization between substation and control center environments might enable system-wide applications such as:
- Wide-area protection algorithms
- System-wide live testing of protection schemes
- Creation of micro-grids and intentional islanding
- Integration of distributed generation
- More accurate state estimation through synchrophasor collection
- Distribution of metering data throughout the utility
In this way, the next generation of IEC 61850 configuration tools may lead to something even bigger:the ability to build not just complete substations, but an intelligent power grid.
About the Authors
Grant Gilchrist, P.ENG. is a consulting engineer for EnerNex Corporation and a recognized expert in data communications for the electric power industry, particularly in areas relating to Internet protocols, OSI, security, and SCADA applications. He has been extensively involved in standards development for the IEC, IEEE, American Gas Association, Standards Council of Canada, and the DNP Technical Committee. Gilchrist was a key contributor to the EPRI IntelliGrid Architecture and Utility Communications Architecture. He has been actively involved in the development of the IEC 61850 series of utility communications standards, and a key contributor to the rollout and deployment of IEC 60870-5 protocols.
Ron Farquharson is a consultant in utility automation for EnerNex Corporation. He has over 25 years experience in substation control, automation, and monitoring. Farquharson spent the bulk of his career at GE/GE Harris/Harris/Westronic, where he held numerous positions in product management/ marketing and project management.He chaired the Task Force in the IEEE PES Substations Committee called "The Use of Computer Technology in Substation Data Acquisition and Control." He was also a key driver behind the DNP protocol development at Westronic and the decision to form the DNP User Group. He currently serves on the DistribuTECH Conference Advisory Committee.
