Composite generation and transmission system reliability assessment using impact increment-based state enumeration method

Abstract

An impact increment-based state enumeration (USE) method is designed to assess reliability of composite generation and transmission systems. The reliability index calculation formula of the traditional state enumeration technique is transformed into an impact increment-based formation. Based on the derived equation, the traditional state enumeration method is modified into an impact increment based one. With the proposed method, calculation of state probability are effectively simplified, and reliability indices of high accuracy can be obtained with only low order contingency states. When it is applied to composite systems, load fluctuation can also be considered by replacing impact increments with their expectations under various load levels. Case studies are performed on the RBTS system and the RTS-79 system. Results indicate that annual reliability indices can be efficiently obtained with the USE method. Comparing with traditional state enumeration and Monte Carlo simulation methods, the proposed method is more precise and efficient.