Fault localization to improve power system quality in distribution networks: a greedy approach to optimize the switching sequence of remotely-controlled devices

The developments in Information and Communication Technology (ICT) and electronic sectors have enabled regulators to set strict Power Quality targets, especially regarding the continuity of supply, such as the System Average Interruption Duration Index (SAIDI), that distributors must comply with to avoid penalties. Accordingly, distribution system operators (DSOs) have started introducing remote control and automation on the power system, but accurate and robust methodologies are required to identify where the fault occurred. When a fault happens, an entire feeder goes off-service, however by operating the remotely-controlled disconnectors and switchgears along the feeder, the distributor can speed up the system restoration process, thus avoiding the manual intervention by maintenance teams. In this paper, we describe an iterative heuristic-aided methodology to locate of the fault in a distribution network by acting on remote-controlled switches. In every iteration, all the possible actions aimed to quickly locate the fault are evaluated and the corresponding impact of the reliability indicator (SAIDI) is calculated. Then, the action with the lowest SAIDI is selected. The proposed methodology is flexible and can be generalized to any topology, including the restoration by an adjacent feeder. A numerical case study is proposed and discussed.