OPTIMAL RANKING OF MEASUREMENTS FOR STATE ESTIMATION BY THE GRADIENT PROJECTION METHOD

Optimal measurement ranking is the first and essential step in meter selection for the design of a reliable measurement system. This paper presents a computationally-efficient algorithm for the optimal ranking of measurements for state estimation. The algorithm maximizes the accuracy of estimates with respect to the measurement variances by performing a transformation on the problem.formulation, and minimizing the resulting cost function subject to a set of linear constraints. The proposed algorithm is based on the gradient projection method and includes some new computational features. Computational efficiency of the solution procedure is significantly improved by converting the constraints into a linear form through a transformation, using an analytical expression for the derivative of the cost function, employing the sparse inverse matrix technique and optimal ordering for the evaluation of the cost function and its derivatives, and simplifying the evaluation of the projected gradient vectors. Performance of the algorithm is demonstrated on the IEEE 14, 30, and 57 bus systems.