Coordinated State Estimation of Power Transmission and Distribution Systems

This paper introduces a coordinated state estimation (CSE) approach designed to achieve a unique reference solution for both transmission and distribution systems. The CSE framework additionally addresses the challenges related to balanced bus requirements within distribution system state estimation (DSSE). Specifically, the CSE method models a transmission boundary bus as a reference bus for the execution of DSSE. Furthermore, the methodology constructs a consistency check vector based on the estimated variables of the modelled reference bus, thereby ensuring the coherence of the solution for the entire power system. To manage the substantial complexity of the problem, the CSE approach employs a parallel estimation strategy. This paper validates the CSE technique through a comprehensive analysis of different power transmission and distribution system combinations. The study focuses on the IEEE 14-bus and New England 39-bus systems as transmission networks, alongside the IEEE 13-node and 37-node feeders as distribution networks. Validation is conducted using MATLAB and DIgSILENT PowerFactory software tools.