ADEQUACY EVALUATION OF COMPOSITE POWER SYSTEMS
There is a growing interest in the power industry in quantitative assessment of composite generation and transmission system adequacy evaluation. This thesis attempts to further the state of the art in adequacy evaluation of a composite system by evaluation, analysis and solution of some specific problem areas. A contingency enumeration approach is utilized in the adequacy evaluation of a system. As the size of the system increases, inclusion of high level outage contingencies, particularly generating unit contingencies, becomes necessary. This, however, increases the computation time tremendously. As a good compromise, contingencies after certain outage level can be included by modifying the indices at the last level. This phenomenon is designated in this thesis as termination of an outage event. The effect of the termination and the inclusion of high level contingencies on the adequacy indices is discussed in this thesis with respect to practical applications. Some of the problems encountered in a network adequacy evaluation are bus voltage violations and non-convergence A.C load flow situations. A heuristic algorithm has been developed to solve these problems by rescheduling the generating units in the system and injecting reactive power at voltage violating buses. The capacity deficiency in the system under any outage contingency is alleviated by curtailing the load at appropriate buses. A load curtailment philosophy is developed and discussed in this thesis. Calculation of both individual load point .and overall system ind ices is necessary in order to assess the adequacy of a load point and of the system as a whole. These indices do not substitute for each other, they complement each other. The thesis stresses that the interpretation of the indices should be done in the domain within which they lie and that it is not valid to draw any conclusion about the adequacy of a load point from the system ind ices. Two sets of indices, annualized and annual, are described and calculated for the systems discussed in this thesis. The effect of including common cause and station originated outage events.on the system adequacy is also analyzed and illustrated by practical examples.