A personal computer based system for the laboratory evaluation ofhigh performance power system protection relays

The power system simulation system described provides a relay under evaluation with current and voltage input similar to that encountered under service and fault conditions. Using digital transient simulation programs to model power system behaviour, the facility provides an effective bandwidth of from DC to 4 kHz for both the current and voltage relay input. The relay's output is automatically monitored during the test, enabling a detailed report of its response to be produced. The application of the system is illustrated by the evaluation of a new EHV teed feeder relaying system