Considerations on three-phase modelling for branch-current state estimation

Abstract

Over the years the studies on branch-current state estimation (BCSE) methods and algorithms have shown good performance in comparison with the classical node-voltage based model for distribution systems (DS). However, when it comes to its practical application, the required detailed system modelling that considers all components such as transformers and regulators is not comprehensively described in the literature. The major contributions of this paper are the discussion on the component modelling, the required changes on the BCSE formulation that incorporates various models of transformers and regulators. The substation voltage estimation is also performed applying concepts of multi-sensor data fusion theory that deals with different classes and types of measurements. Classical test feeders were used to evaluate the proposed models and the method was able to estimate the DS state reliably with good performance for all test cases. The components models and the power flow results have been validated with OpenDSS software, and it can be used as a reference for future development of this class of method. • Critical review of the Branch-Current State Estimation. • Detailed modelling of transformers to the Branch-Current State Estimation models. • Development of Phase decoupled model for Branch-Current State Estimation. • Application of Data Fusion Theory to deal join the estimate of from distinct estimation process. • Performance evaluation with benchmark test systems from the technical literature.