Redundancy analysis and observability restoration based on the Gram matrix factorization

This paper presents a method for observability and redundancy analysis. It is numerical method based on the Gram matrix factorization. The identification of critical measurements and critical sets of measurements is done after the backward factorization of the Gram matrix. The common numerical problems are avoided since the residual sensitivity matrix is not required in the proposed technique for identification of critical measurements and sets. The accuracy of the algorithm is analyzed and tested on a simple example and the IEEE 14-bus system. The presented case studies are used to discuss scalability issues of the method and its application to real-time operation.