現代饋線配電系統中，饋線上通常建置通訊設備，稱為饋線末端設備 (feeder terminal unit, FTU)。這些通訊設備傳輸通過饋線上電流大小值至控制中 心，同時其可以接受控制中心命令，以改變饋線上開關狀態。配合內建於控制 中心電腦內之專家程式FDIR (fault detection, isolation, and service restoration)， 此使饋線配電控制中心可以監視及偵測饋線上停電事故。當持續性停電事故發 生時，此配電系統可以自動隔離事故區段並有效地恢復鄰近區段供電，以縮小 停電範圍。不過，饋線配電自動化系統成功之關鍵在於FTU 提供給專家程式 FDIR 判斷的現場訊息之準確性。實務上，FTU 的動作由電流－時間平面上之 時間電流協調曲線 (time coordination curve, TCC) 決定。因此，為有效提升供 電力供應的可靠度，TCC 的設定方式應嚴肅考慮。本文提出設定TCC 的方法 以降低專家程式誤判發生率。並提出一種判準，達TCC 之最優化設定。最後， 應用模擬退火演算法計算取得多點之設定，以符合將來FTU 技術提昇時之需求。

In a modern distribution system, many communication apparatus are built in the feeders. The apparatus, called Feeder Terminal Unit (FTU), can transmit the information of the magnitude of the current through the feeder to the control center. FTUs can receive the commands of the control center to open/close switches on the feeder. The modern distribution system can operate automatically. Applying the expert program FDIR (Fault Detection, Isolation, and Service Restoration) in the computer of the control center, the system has the functions of telemetry, monitoring, and remote control to detect feeder fault. When a fault occurs, the system will open/close several switches automatically to isolate the de-energized zone by the program. Thus, this system can narrow the section of power outages and effectively restore the power supply of the neighbor sections. But this system can work well only if the information that provide to FDIR by FTUs are accuracy. In practice the action of a FTU is determined by the associated Time Coordination Curve (TCC) in current-time plane. For the purpose of improving the reliability of electric power supply, the method of setting TCC of FTU shall be examined seriously. In this paper we discuss how to set up TCC to reduce the misjudgment of FDIR. And a criterion to reach the optimal setting for TCC is proposed. Finally, we apply the simulated annealing method to calculate TCC in order to meet the demand for the upgrade of FTU in future.