Some Aspects of Migration from Present Solutions to Sa Systems Based on the Communication Standard Iec61850

Today many substations exist with a multitude of different communication systems and architectures. Extension and retrofitting of stations are natural opportunities to introduce the IEC61850. It can be that an extended part of a substation is equipped with the new standard and then need to be integrated into the older part that is based on presently available communications. When retrofitting a substation, the substation may be supplied entirely with newer generation secondary equipment whereas the primary equipment remains based on a conventional solution. This will cause different migration steps. These migration steps will result in a requirement for protocol conversions and engineering. This paper shows with some examples how these migration steps can be made and the resulting requirements on data conversion, backward compatibility and engineering.