Adequacy Evaluation of a Small Area in a Large Composite Power Network

The adequacy evaluation of a composite power system involves the examination of both generation and transmission facilities in a network. The major developments in the area of adequacy evaluation of composite power networks to obtain appropriate indices at the major load points have occurred over the last twenty five years. During this time, there has been considerable interest amongst power utilities, research organizations, and universities in developing suitable models, solution techniques, adequacy indices and in collecting relevant data to conduct studies on bulk power systems. Most power utilities in North America are, however, still using deterministic criteria as opposed to probabilistic criteria in adequacy assessment of their bulk power systems. There are many reasons for this but one of the important ones is the lack of a suitable methodology that provides the required information regarding adequacy performance. An actual power system tends to be quite large and a thorough examination of all credible outages involving system components is not practical due to the large computation time required to solve the network under these outage situations. Attempts have been made to calculate the adequacy indices of large power systems using approximate techniques which either make use of simplifying assumptions or utilize approximate solution techniques. They also do not consider all the credible outages that might significantly affect the performance of a power system. It should be noted that there is no simple or magic solution for overcoming these difficulties.