Implementation Experiences

One of the main questions for utilities is whether detailed specifications for IEC 61850 based systems are needed or is there benefit in not having it specified in great detail? One should keep in mind that systems can very well be described using the traditional approach based on the:

• Single line diagram
• Functional requirements
• Dependability requirements
• Performance requirements
• Environmental requirements
• Project management
• Services

Advantages of not having detailed specifications is that not only optimized solutions are possible based on specified functions and performance but also that most manufacturers will be able to offer a solution complying with the specification. On the other hand a detailed specification supports the standardization of substations.

No matter what approach is chosen during the project design phase the described functionality has to be mapped by the system integrator to the IEC61850 data model and implementation agreements on the modeling of multifunctional IEDs will help in the development of tools for automatic processing of SCL files and IEC 61850 based user interfaces.

Now that the system integrator has been mentioned there exists controversy today whether the role of the integrator can be outsourced by utilities or not? The answer is nor easy nor without controversy but the main topics influencing the answer are:

• the business model that the utility has irrespective of the solutions that are chosen
• the fact that a system integrator needs a lot of expertise with the specific utility systems
• that there is a requirement for a technical think-tank to deal with new and enabling technologies
• what to do if you have multiple projects?

It is expected that pure integrators will emerge and the role of the integrator will evolve. New roles, such as that of the system architect, are envisioned.

Another controversial topic is that of project specific extensions of existing standards. It is clear that such approaches lead to an exact fit for a single project, but also to uncontrollable test efforts and specific conformance tests and test equipment. The flexible IEC 61850 toolbox and the possibility to extend the Data Model is a big seduction for experts wishing to implement their ideas and knowledge into a standardized framework. Therefore improvements and extensions must be discussed in IEC TC 57 in order to integrate them into IEC 61850 but not every wish may be fulfilled. Fortunately the IEC 61850 System Configuration description language supports the exchange of configuration data between manufacturers and warrants consistent and interpretable data in engineering. It also supports automatic test and application configuration as well as adherence to the standard, i.e. avoiding user-specific adaptations, ensures multi-vendor interoperability.

Finally one has to keep in mind that a single utility semantic model facilitates staff adjustment and work reuse in the utility and allows the application of vendor-independent tools with significant benefits for automation system operation, maintenance and diagnostics.