Abstract :
Relays offered to the electrical supply industry have over many years reported only the end status of all operations by target flags or LEDs. These are regularly reset to avoid overwriting of previous indications. This limited data, combined with the limitation this imposes in fault analysis not only with system faults but also obscure relay performance and failure prediction, are aspects of systems performance that are expensive and time consuming for the industry to investigate. The advent of computer based protection control and monitoring equipment for generation, transmission and distribution systems has allowed the major relay manufacturers to provide a man-relay dialogue not previously possible. The system fault recording and reporting in chronological order of entire events and sequences of events has created new opportunities for cost saving, time saving and improved quality of power supply