Contingencies Evaluated by a Z-Matrix Method

A method has been developed suitable for on-line evaluation of contingencies that requires a relatively small computer. The effect on critical lines, produced by removing a line from service or by changing the generation schedule, can be determined as an on-line function of a computer that is installed in the system operator's office. The method can also be used by system planning personnel to reduce the number of detailed power flow cases that must be made in an expansion study.