Optical fibre signalling for protection purposes

Modern digital signalling techniques now offer considerable improvements in power system protection signalling. By using optical fibre technology, distance protection and intertripping can be considerably improved in speed, reliability and security with simple, status and command mode signalling. The authors discuss an application of optical technology which provides a number of very fast and secure signalling commands over optical fibres associated with a 132 kV line and satisfying most requirements for signalling diversification or duplication