The existing feeder automation (FA) mostly designs the algorithm based on the fixed network topology and tie switch position. The algorithm of FA system needs to be reconfigured if the feeder topology changes. Tie switches can be recognized and the algorithm can be adjusted automatically by detecting the voltages of switches with potential transformers installed on both sides. The smart terminal unit (STU) can recognize the feeder topology and the position of tie switches by ‘relay inquiry’. STUs of adjacent switches locate and isolate the faults by exchanging fault current information. STU monitoring tie switch restores maximum power supply according to the real-time feeder topology and the capacity of backup source. The static simulation test and field application proves that the proposed method can automatically adapt to the change of feeder topology

quickly isolate the fault and restore the power supply. This work is supported by National Natural Science Foundation of China (No. 51177096) and State Grid Corporation of China (No. 031〔2012〕19).