Adequacy equivalent development of composite generation and transmission systems using network screening

Reliability evaluation of a large composite generation and transmission system involves extensive and time-consuming calculations. Application of reliability equivalent networks therefore seems necessary in the reliability evaluation of large power systems. An approach is presented to develop an adequacy equivalent of a composite system using network screening. In the proposed method, a power system is divided into two portions designated as the study area and the external area. The goal is to find the adequacy equivalent of the external area in order to facilitate extensive reliability studies in the study area. The elements in the external area are ranked or screened based on their impacts on power flows in the tie lines between the two areas. Owing to their less impact, the lower ranked elements are considered to be involved in a network reduction technique. Simulation studies are conducted on the IEEE-RTS-96 and the performance of the developed procedure is thoroughly discussed.