Experience in distribution state estimation preparation and operation in complex radial distribution networks

This paper presents an industrial experience, problems and solutions in the field of distribution state estimation, observed on complex projects involving the implementation of real time distribution management system (DMS) control centers. It is based on previous work, an optimized Real-Time Distribution System State Estimation (RT-DSSE) algorithm for solving large three-phase radial unsymmetrical networks. It uses active and reactive power, current magnitude and voltage magnitude measurements. To be able meet its strict RT performance requirements, in this continuation, several challenges which arise in industrial RT DMS systems for the given network types are analyzed and incorporated into the whole RT DSSE algorithm. Topological network analysis and network object model optimization is done through several steps to reduce the problem size. Loads are modeled using the Advanced Load Scheduling System to obtain the best possible initial load values. Subsequently, special per phase measurement areas are created and pre-estimation of current magnitude measurements to power is carried out, further reducing the problem size. Only then is the main estimation algorithm executed by the weighted least squares error method.