An investigation into the design of an IEC 61850 based protection relay.

IEC 61850 is a new international standard for the communication networks and systems in substation which allows the implementation of high-speed peer-to-peer communication based applications. The new standard has significant impact on the development in power system protection and provides a vehicle for future advances in many areas. All major substation protection and control equipment manufactures have been developing the new substation communication technology. At present, they can provide products which can support both IEC 61850 and conventional hard wired schemes. With the introduction of IEC 61850, those concepts generally associated with computer architectures have been introduced into the world of the power system equipment. These have immediate applications in new types of protection and are leading to a new generation of relays. Communications is fundamental to these systems and enable new ideas to be realised which offer advantages for the protection world. This paper describes the impact of IEC 61850 on the design of the next generation of protection relays. It explains the operation of the different communications buses and how these are incorporated into the overall protection scheme. The paper also describes some of the alternative communication approaches that can be used to maximise the advantages to the protection system users and provide the features inherent to complex protection schemes. The acceptance and acceptability of these new protections is the major challenge for the young power system protection engineers and the electricity supply industry as a whole.