Application of a Wide Area Backup Protection Expert System to Prevent Cascading Outages

A strategy to prevent cascading outages in power systems is proposed in this paper. The strategy employs wide-area back-up protection and artificial intelligence techniques to minimize the impact of a fault on a network. There are two ways in which wide-area backup protection can prevent cascading trips leading to a wide spread blackout: 1) Precise location of a fault so that only the circuit breakers necessary to isolate the fault are tripped; and 2) Avoidance of unnecessary trips, due to hidden failure or overloading, by blocking the trip signals of conventional back-up protection relays. The limitations of conventional back-up protection are examined and methods of improvement are presented.