A NEW MODEL FOR RELIABILITY EVALUATION OF 2 COUPLED NETWORKS

The reliability indices LOLP and EDNS are evaluated for two coupled networks. A new model is developed to simulate the MW-capacity export between the two networks. The model replaces the tie lines by two-twin hypothetical generating capacities. The FOR's of these multistate capacity units are evaluated after building (i) the generation schedule curve GSC, (ii) the MW-export curve MEG, and (iii) MW-import curve MIC for each network. The two networks are then decoupled. Two multistate, MW-import of positive capacity and MW-export of negative capacity, hypothetical units are added to the installed generation capacity of each network. Evaluation of reliability indices LOLP and EDNS is then processed for each network alone. The MW-capacity of tie lines is varied from zero and up to its peak value, deducable from the MW-export/import curves. The results obtained for two sample examples indicate that (i) increase of tie capacity is not absolutely beneficial and the coupling may be beneficial for both networks if constrained tie capacities are adopted. Peak as well as optimal tie capacities are reported.