Abstract
Utilities are trying to install the equipment of high quality to avoid deterioration of supply reliability. In addition, many sectionalizing switches which can decrease the total outage value for a fault are installed for the same reason. Therefore, utilities are interested in stun dards and criteria for installing switches to optimize the total cost on distribution systems. The affect of sectionalizing switches installed on distribution feeder is gradually decreased because the failure rate on distribution feeder is decreased. Also the automation for distribution systems is widely applied for the efficient operation. Therefore, the renewal for installation standards of sectionalizing switches Is required to reflect the current operation situation. The variable data is used to consider the KEPCO's real situation of distribution feeder as follows; the feeder capacity, connecting rate, feeder length, failure rate of distribution feeder, the failure rate of switches, perception time of feeder fault, the restoration time for a faulted section, the transfer time to other feeders, and the switching time. In this study, We propose equations which can determine the number of sectionalizing switches for minimizing the outage and switch installation cost.