Simulation aid to the prediction of transmission system protection performance

This paper describes the development of an EMT model of the 275/132 kV SESCO system. This time domain calculation allows the dynamics of sequential operation of circuit breakers and single pole auto-reclosing schemes to be accurately modelled and provides much more detailed information than would be available from a steady state, phasor domain, short circuit, or fault flow calculation. The model has enabled past protection operations to be verified and is a valuable tool to assess the effect of system development on the protection performance.