ICIC Express Letters ICIC International c °2008 ISSN 1881-803X Volume 2, Number 2, June 2008 pp. 137-142 A PROBABILISTIC RELIABILITY EVALUATION OF KOREA POWER SYSTEM Jeongje Park 1 , Sangheon Jeong 1 , Jaeseok Choi 1 Junmin Cha 2 and A.(Rahim)A. El-Keib 3 1 Department of Electrical Engineering Gyeonsang National University Gazwadong 900, Jinju, GN, Korea honeytop04@hanmail.net; pakjan81@gmail.com; jschoi@gnu.ac.kr 2 Department of Electrical Engineering Daejin University Gyunggi, Pocheon, Korea chamin@daejin.ac.kr 3 Department of Electrical and Computer Engineering The University of Alabama Tuscaloosa, Alabama, 35487-0286, USA El-keib@eng.ua.edu Received January 2008; accepted March 2008 Abstract. Reliability and power quality have been increasingly important in recent years due to a number of black-out events occurring throughout the world. This paper presents a practical method of probabilistic reliability evaluation of Korea Power system by using the Probabilistic Reliability Assessment (P RA) program and Physical and Operational Margins (POM). The case study computes the Probabilistic Reliability Indices (PRI ) of Korea Power system as applied P RA and POM. It takes a large number of contingencies in load simulations and combines them with a practical method of characterizing the effect of the availabilities of generators, lines and transformers. The effectiveness and future works are illustrated by demonstrations of case study. The case studies of Korea power system are shown that these packages are effective in identifying possible weak points and root causes for likely reliability problems. The potential for these software packages is being explored further for assisting system operators with managing Korea power system. Keywords: Probabilistic reliability evaluation, PRA, PRI , Korea power system 1. Introduction. This paper presents the result of marginal power flow evaluation per- formed on Korea power system using two commercial software packages: Physical and Operational Margins (POM V. 3.4) and Probabilistic Reliability Assessment (PRA V. 4.0) developed by V&R Energy System Research and EPRI, respectively [1-3]. The methodology presented in this paper has been implemented in a package of soft- ware. The contingency simulation program called Physical Operation Margin (POM) simulates a large number of contingencies. It is described in a paper presented in this conference [4]. An output file of POM which contains the results of the critical contin- gencies and their impacts is then used as one input to the PRA program package which includes two components, the Probabilistic Reliability Indices (PRI ) software and a post processor. The PRI module computes the deterministic and the probabilistic reliability indices. The post processor analyzes the reliability performance of the transmission grid and displays various results which make up a systematic Probabilistic Reliability Assess- ment (PRA) [5]. The real database for accurate assessment of the outage data of system elements (lines, generators and transformers, etc.) in the Korea system has not completed yet. Thus, the operating outage databases in other countries are used in this paper. The 137