A method for the assessment of voltage sags in power systems based on sparse matrix factorization

This paper details the application of two sparse matrix factorization techniques based on LU and LDU decomposition processes, whose solution allow taking advantage of the sparse structure of the conductance matrix obtained by companion-circuit analysis (CCA) through the application of the trapezoidal rule (TR) in medium/large-scale power systems. The main purpose of this application is to obtain powerful analysis tools that combine the CCA method and two factorization techniques (e.g. CCA
TR
-LU and CCA
TR
-LDU) to obtain the solution of power systems without requiring a large amount computational effort. The combined methods are now applied as a tool for the study of voltage sags in the modified IEEE 30bus test system, in order to demonstrate its accuracy and CPU time. The results obtained by the sparse methods (CCA
TR
-LU and CCA
TR
-LDU) are validated in terms of accuracy and CPU time against those obtained by the conventional methods (CCA
TR
-LU and CCA
TR
-LDU) and the PSCAD/EMTDC
^®
simulator.