Fault-Observability Enhancement in Distribution Networks Using Power Quality Monitors

As far as continuous supply and reliable power delivery to the distribution system customers are concerned, finding a practical and cost-effective method for locating faults after their occurrence is of high importance. In this study, a method is proposed to determine the optimal number and location of power quality monitors (PQMs) to make the distribution network fault-observable, that means, to be able to locate faults as precisely as possible. Moreover, as placement of PQMs is highly dependent on the network topology, the proposed method considers the most probable configurations of the network for optimization. The error of measuring equipment and its effect on number of PQMs is also taken into consideration. The defined objective functions of this study aim to minimize the cost of installing PQMs while minimizing the number of blind-pairs and maximizing the fault-observability level of the network. These objective functions are optimized using Multi-Objective Particle Swarm Optimization (MOPSO) technique. Additionally, to have a better economic evaluation, two scenarios are defined based on the accuracy class of monitoring equipment. The effectiveness of the proposed method is corroborated using simulation results for the IEEE 123-bus distribution test system.