Observability Assessment and Optimal Placement of Measurement Terminals in Distribution Networks with Graph Theory and Intelligent Optimization

As an essential part of power grids, it is crucial to measure and master the operation state of distribution networks in real time. This paper proposes an approach for observability assessment and optimal placement of measurement terminals in distribution networks. Based on existing measurement terminals, the approach searches observable islands by graph theory and then calculates an observability assessment indicator. When the system state is unobservable, an OPMT scheme is provided by intelligent optimization algorithms. By deploying a minimum number of measurement terminals, the approach ensures that the status of all nodes in the distribution network is observable, thereby reducing investment costs of measurement terminals and improving the situational awareness of distribution networks. The proposed approach is verified by case studies with the IEEE 123-node system and a real-world distribution network.