Distributed Distribution Automation system based on the identification of tie-switch

Distribution Automation (DA) could realize fault location, isolation and service restoration (FLISR), which is an important means of improve power supply reliability. Generally, to perform power supply restoration, the operator needs to know the position of tie-switch, which may vary due to structure changes in the distribution network. As a solution, a kind of distributed tie-switch identification method based on the smart terminal unit (STU) is proposed in this paper, with which fast service restoration can be realized in changing network structures. In this method, voltage transformers are not required to be mounted on switches, and the tie-switch identifying process can be accomplished without relying on the master station. The method can be carried out in normal operation time and fast service restoration could be realized even if the structure of the network is changed, and lab tests have been performed to verify the smart terminal unit´s capability in the identification of tie-switch.