Transmission System Reliability Evaluation in the Central-1 and Northern Regions of the Lao PDR in Corresponding to Transmission System Development Plan

This paper investigates the 115 kV transmission system development plan of Electricite du Laos (EDL), specifically for the transmission line projects in the Central-1 and Northern regions of the Lao PDR for the years 2010-2020. The steady-state power flow analysis at peak demand conditions is based on N-l contingency criterion. The adjustment in transmission system development plan of EDL is to improve the reliability of such regional networks for the given years based on the economic justification (economic internal rate of return, EIRR and benefit cost ratio, B/C Ratio). The economic justification will be accomplished to indicate the internal rate of return and benefit cost ratio of each transmission system expansion project. This paper is used DIgSILENT program to calculate the steady-state power flow analysis and Transmission System Reliability Assessments. The results of the studies have shown that, power losses, energy not supplied (ENS), system average interruption frequency index (SAIFI), system average interruption duration index (SAIDI), are also reduced. In addition, the economic internal rate of return (EIRR) and benefit cost ratio, (B/C Ratio) of each project can assist planers to make a reasonable discussion or determination to reinforcement and expansion planning.