FAST ADEQUACY ASSESSMENT OF COMPOSITE POWER SYSTEMS

Abstract

Quantitative adequacy assessment of a composite power system is generally done using a contingency enumeration approach. Exhaustive adequacy analysis includes the evaluation of· contingencies, the classification of these contingencies according to selected failure criteria· and the accumulation of adequacy indices. Various. contingency enumeration approaches are available to analyze the adequacy of a composite power system depending upon the failure criteria and the intent behind the studies. Adequacy indices are calculated using DC and AC load flow methods in this thesis using two selected test systems. The differences in the indices resulting from using these load flow methods are discussed. The inclusion of high level outage contingencies can not be ignored in the calculation of representative adequacy indices in relatively large systems. This requirement, however, significantly increases the computation time. One of the most widely used approaches to reduce the computation time is to rank the outage contingencies using fast techniques and then investigate these ranked contingencies using an AC load flow method. This procedure is then terminated by. an appropriate stopping criterion. In this thesis, adequacy indices are evaluated using different ranking methods. The computation times and the differences in the adequacy indices as compared with a base case AC solution are discussed. A new technique designated as the selection method is introduced to reduce computation time. This method can be used to examine both the continuity and the quality of power supply at major load centers for any type of contingency. The method is well suited for large power networks because of the reduced computation time and. storage requirements. In this thesis, the application of the method and its comparison with the base case and with various ranking methods are illustrated using two test systems.