Introduction: Two collaborative projects, working with all GB Transmission network owners and specialist academic institutions evaluating the opportunities that may be offered by the possible future deployment of IEC 61850 based protection systems.

Objectives: The application of the IEC 61850 standard for substation communications is becoming wide spread in substation automation systems around the world. Recent development of Non Conventional Instrument Transformers (NCIT), Merging Units (MUs) and widespread deployment of micro-processor based relays permit truly effective implementation of all-digital protection systems. The process bus defined in the IEC 61850-9-2 increases the possibilities of new substation designs and automation and protection solutions. The utilisation of high-speed peer-to-peer communications of Generic Object Oriented Substation Event (GOOSE) messages and multicast sampled values from Merging Units over Ethernet allows for the introduction of distributed and wide area applications. Such applications provide some significant advantages over conventional protection and control systems while it calls for an assessment of their impact on the performance of the associated protection and control schemes to ensure that any aspect of the novel implementation does not degrade system performance.

The two projects aim to assess the operating performance of an IEC 61850-9-2 based protection scheme for a 400kV transmission system mesh corner and evaluate digital substation architecture design, undertake reliability/ availability analysis and undertake current transformer and voltage transformer merging unit performance tests.

Laboratory based research will evaluate issues relating to system reliability, security, dependability, interoperability and operating speed. The performance will be compared with that of a similar protection system implemented using traditional hard-wiring.