Reliability worth evaluation for distribution system planning and operation using improved actual performance data

It is widely known that in reliability cost/worth analysis, customer outage cost should be taken into account for the delivery of energy services. Several methodologies have been proposed. However, these methods require a lot of long term statistical data e.g. failure and repair rates, which may not be available at present in developing countries. There are some researches considering reliability cost/worth in term of Actual Performance data. Nevertheless, this method can only evaluate the past performance indices according to its past actual performance data. From this reason, it may not be possible to make a reasonable decision in distribution system planning and design. This paper proposes an approach to cope with this problem. The past performance data and the targets of system planning, customer average interruption duration index (CAIDI) and average power not supplied (APNS), will be used to generate the expect interruption events. To handle the uncertainty in setting the system targets, fuzzy concept is then applied. In this paper the proposed method together with Thailand´s customer damage model (CCDF), obtained from the study conducted in the years 2000-2001, is employed to evaluate the reliability worth of the distribution system in Thailand.