SUBSTATION CONFIGURATION LANGUAGE

One of the key advantages of IEC 61850 based systems is the availability of the Substation Configuration Language that allows interoperability and a seamless integration process. The SCL is basically a system specification of the substation equipment connections in a single line diagram. It also documents the allocation of Logical Nodes to devices and equipment of the single line to define functionality, access point connections, and sub network access paths for all possible clients. And finally, it defines the instantiated data model of the different IEDs including optionally preconfigured values for configuration parameters.

What is of specific interest for protection and control applications is that it allows the development of engineering tools for configuration, protection coordination and testing that use a common standard data format.

SCL based configuration process

The overall functionality of any IEC 61850 compliant device is available in a file that describes its capabilities. This file has the extension "ICD" meaning IED Capability Description. The system specification tool supplies to the system configuration tool information such as the single line diagram of the substation and the required logical nodes. The file extension for this file is "SSD" meaning System Specification Description.

The system configuration tool then provides information to the IED configuration tools regarding all IEDs, communication configuration and substation description sections. This information is in a file with the "SCD" extension meaning Substation Configuration Description. This information also needs to be provided to the other tools in order to allow them to configure the set of functions to be performed.

The Standard IED configuration tool sends information to the IED upon its instantiation within a SAS project. The communication section of the file contains the current address of the IED. The substation section related to this IED may be present and then shall have name values assigned according to the project specific names. This file has an extension of "CID" meaning Configured IED Description. Currently there is ongoing work to expand the content of this file to include all settings, thus providing the required configuration data for both the IED itself, and also for the different functional tools.