Monitoring and optimization of power transmission and distribution systems.

摘要

We investigate the state estimation application and present details of the modified implementation to account for two types of power flow controllers. Issues of observability, robustness against bad data, initialization and convergence characteristics are discussed within this dissertation.; We present a tracking state estimator for systems operating under non-sinusoidal but periodic steady state conditions. The proposed estimator is designed to be computationally efficient by transforming the measurement equations in a special manner so that the sparsity of the corresponding discrete time matrix equations is significantly enhanced. Zero injection constraints are also included to take advantage of the increased redundancy.; We present an algebraic method that uses the triangular factors of singular, symmetric gain matrix to determine the observable islands of a measured power system. This is accomplished in a non-iterative manner via the use of selected rows of the inverse factors. Implementation of the proposed method presents little additional effort, since sparse triangular factorization and forward/back substitution procedures common to existing state estimators, are the only required functions.; A multiple measurement placement algorithm is developed based on the observability analysis algorithms described above. This algorithm has the ability to update the measurement set of an unobservable system by placing multiple measurements in a non-iterative manner. This is an improvement over the conventional approach where measurements are added one at a time until full observability is attained.; The newly proposed observability analysis algorithms are also extended to the Hachtel's formulation of state estimation. This extension facilitates the use and integration of developed techniques in commonly used programs by industry.; This study accounts for the voltage harmonic distortion brought about by the placement of capacitors. The optimal capacitor placement problem is formulated as a mixed integer nonlinear programming problem which determines the location, type and size of the shunt capacitors to minimize the harmonic levels, losses and the capacitance costs. A heuristic method is used to obtain a near optimal solution for realistic size systems.