An improved investment priority decision method for the electrical facilities considering reliability of distribution networks

This paper proposes an improved investment priority decision method of the facilities considering the reliability of distribution networks. The proposed method decides an investment order of the facilities combining, by fuzzy rules, the investment priority decision by KEPCO and it by reliability evaluation indices. Where reliability evaluation indices are SAIFI (system average interruption frequency index) and SAIDI (system average interruption duration index). The reliability analysis method of distribution networks applied in this paper utilizes analytic method, where the used reliability data is historical data of KEPCO. Particularly, we assumed that the failure rate increased as the equipment ages. To verify the performance of the proposed method, we applied it with the planned projects to reinforce the weak facility electrical facilities in KEPCO in 2004. The evaluation result showed that, under a limited budget, the reliability of the KEPCO in the Busan region using the proposed method could be enhanced than using the conventional KEPCO's method. Therefore, the results verify the proposed method can be efficiently used in the actual priorities method for investing the electrical facilities.

I. Introduction

These days, distribution network absolutely demands high quality and high reliability for power supply. To meet these needs, utility has set the target for reliability and power quality of customer, has invested the distribution facilities by the works. But the investment method of distribution networks invested in bulk is excluded, under the limited budget, the utility have try to maintain optimal power supply reliability and to maximize the efficiency of the exiting facilities [1]–[4].