Modeling interoperable protection and control devices for substation automation according to IEC 61850

according to IEC 61850 Klaus-Peter Brand, Wolfgang Wimmer Switzerland Summary The standard IEC 61850 „Communication Networks and Systems in Substations“ will provide interoperability for all functions in substations. To realize interoperable devices their data and functions have to be modeled according to IEC 61850. The approach and the data model of the standard is the key for understanding, but for physical packaging the device model has to be applied also. This is shown for a combined protection and control device. Example for protection is the distance protection as known from IEC 60870-5-103. It shows that the limitations of existing devices can be mastered, but that the full benefits can only be exploited with updated or new devices.