Symmetrical Components Based State Estimator for Power Distribution Systems

Real-time monitoring of distribution systems gains importance day by day, as the number of distributed energy resources populate across the system. Distribution System State Estimation (DSSE) will constitute the core of real-time monitoring in modern distribution management systems, serving as a basis for many applications whose effectiveness relies on fast and accurate computations of the system state. This paper presents a three-phase weighted least squares state estimation method based on symmetrical components for distribution systems. In the proposed formulation, the three-phase DSSE problem is decomposed into three single-phase problems which can be solved sequentially or simultaneously by single-phase state estimators. As a result, the implementation complexity and computational times required for DSSE solutions are considerably reduced. The effectiveness and validity of the proposed method are demonstrated on distribution feeders of different sizes and topologies, considering statistical criteria, and computational efficiency. Results show that the proposed method estimates the state of large distribution systems significantly faster and with comparable accuracy as a well-established DSSE method.