Protection computers or protection relays?

The recently introduced communications standard IEC61850 is having a major impact on the structure of new protection systems and schemes. In itself it describes the concepts for sub-station communications covering protection, control and metering functions. However, although it is going to have a major impact on the power systems communications, it will also influence the design of future protection systems. How are protection systems going to develop in light of IEC61850? Will these be protection computers or protection relays? The aim of IEC61850 is to reduce costs, respond to the increasing demands for communications and to provide for standard protocols available from different manufacturers. It aims to provide for future-proofed equipment, interoperability of equipment from different manufacturers and easing the management of future power system sub-station equipment. There will also be a host of other opportunities and advantages that can be realised. These include easier repair, refurbishment and replacement of protection. They also provide for greater use of general purpose IEDs, self healing systems, and plug and play type facilities. The paper examines how future generations of protection systems will develop in order to meet these objectives. It takes a close look at the development of distributed computer systems and draws several parallels from this pointing to the possible future computerised protection. The future for protection systems is full of change, challenge and promise. The rate of change will be governed by the acceptance of the new concepts by the industry. Change is inevitable and the driving forces are well established.