An Incremental Reliability Assessment Approach for Transmission Expansion Planning

Abstract

Reliability assessment is of great importance to transmission expansion planning (TEP). In this paper, a novel incremental reliability assessment approach (IRAA) for TEP is proposed. The basic idea is to build an incremental reliability indices calculation model so as to quantitatively estimate the degree of reliability enhancement with high computational efficiency. First, contingencies are categorized into three scenarios according to the states of the added components of the planning schemes. Then, contribution of each scenario to the incremental reliability indices is analyzed in detail. It turns out that contingencies of only one scenario can affect the incremental reliability indices and, therefore, other contingencies can be eliminated. Based on this phenomenon, an IRAA is developed for TEP, which can be used to improve the performance of various traditional reliability assessment methods. Case studies are performed on IEEE RTS 24-bus and IEEE 300-bus test system. The results demonstrate that the IRAA has superior performance to traditional methods in terms of accuracy and efficiency.