BCU dynamic security assessor for practical power system models

The proposed hybrid BCU and time-domain scheme for power system security assessment achieves its reliability and accuracy by effective exploration of the merits of both the BCU method (and the improved BCU classifiers) and the time-domain approach. In order to achieve the speed of the proposed hybrid scheme, the time-domain simulation program is called only for two types of contingencies: (1) contingencies which are classified to be unstable by the BCU classifiers; and (2) contingencies whose energy margins are not obtainable by the BCU method. An effective procedure for calculating the energy margin for these two types of contingencies is described. The application of BCU DSA to practical power system models is described in detail.