A practical approach for reliability assessment in multi-objective transmission expansion planning

Reliability enhancement is one of the main objectives of transmission expansion planning (TEP), and reliability evaluating of different planning schemes is one of the greatest challenges in solving the TEP problem. Due to the large scale of networks and high computational burden of the reliability assessment procedure for any network structure, it is almost impossible and impractical to accurately analyze the reliability of all planning schemes during optimization of the TEP problem. In this paper, first, the necessity of performing an accurate analysis on transmission network reliability during multi-objective based optimization of the TEP problem is shown. Then, a practical approach is proposed for solving this problem. The main objective of the proposed approach which is based on classification of events and occurrences of faults, is to make it possible to more accurately analyze the reliability of transmission networks in order to make decisions on the multi-objective TEP, and to achieve a more accurate solution as well; so that the process is not time-consuming and the computational burden is low. To investigate the efficiency of the proposed approach, the modified Garver's network is used and the multi-objective TEP problem is solved using NSGA-II as optimization tool. The results are compared with those of conventional approach. The obtained results show the accuracy of the proposed approach in solving the TEP problem.