Fast super decoupled state estimator for power systems

A new method is developed and presented in this paper to solve the state estimation problem of power systems. The method involves application of a rotational operator to the state and measurement functions resulting in an automatic decoupling of the Jacobian and gain matrices. The elements of these matrices are different from those in the existing decoupled state estimators. A solution is obtained through alternately iterating the active and reactive equations using the constant gain matrix and avoiding the approximation due to the decoupling of the Jacobian matrix. Digital simulation studies on a variety of systems indicate that the new estimator is comparable to the best available version of the fast decoupled state estimator in terms of core size, solution time, mathematical structure, convergence behavior, accuracy, robustness, reliability and versatility. Systems with low and high R/X ratio lines, heavy loading, ill-conditioning, and low/high reference bus voltage are tested. Typical results are provided for illustration.