State estimation for power distribution system and measurement impacts

A distribution state estimator (DSE) based on the weighted-least-square approach and three-phase modeling techniques is presented in this paper. The three-phase model required to formulate the state estimator is developed. Customer load estimates and real-time measurements are modeled as expected values with errors. Particularly, this paper introduces the concept of stochastic results of DSE and has a detailed analysis. Test examples are used for demonstrating the capabilities of a DSE. The influence of the measurement placement and measurement accuracy on the estimated results are discussed. Other system parameters that affect the system state deviations are illustrated. The practice application of a prospective DSE is discussed.