Real-time three-phase state estimation for radial distribution networks

This paper proposes an optimized approach for Real-Time Distribution System State Estimation (RT-DSSE) for solving three-phase radial, unbalanced and unsymmetrical type of networks by utilizing Active and Reactive Power, Current magnitude and Voltage magnitude measurements. As the preparation step, topological network analysis and network object model optimization is done to reduce the problem size. Loads are modeled using the Advanced Load Scheduling System to obtain best possible initial load values. Subsequently, special per phase measurement areas are created and pre-estimation of current magnitude measurements to power is done, further reducing the problem size. Only then is the main estimation algorithm executed by weighted least squares error method. Unlike the traditional state estimation on distribution networks, which by using load data as pseudo measurements produces formulations of very large size, this algorithm is designed to achieve real-time performance requirements in several optimizing steps. Results are presented to show estimation and performance achievements.