Half-Interval Method Applied in Feeder Terminal Unit Overcurrent Detecting Curve Setting

Currently, self-healing is one of the most important functions in the smart grid. Meanwhile, fault detection, isolation, and restoration of feeder automation systems dominate the self-healing function in power distribution systems. The steps of the aforementioned function depend on the fault flag status of the feeder terminal unit. The conditions for setting this flag are judged by the feeder terminal unit overcurrent detecting curve. This paper found an efficient approach to calculate this curve via a half-interval method. Versatile application software with the curve plotting capability was also developed and deployed on the web server of the information-management department of Taiwan Power Company and is running successfully.