Use of base case Jacobians in power flow solution under topological changes

Fast decoupled Newton-Raphson method is the most widely used algorithm for load flow analysis needed in on-line assessment of the steady state securit y of a power system. To repeat the load flow analysis corresponding to the topological changes arising from a contingency or a remedial action, usuall y the base case Jacobian matrices are reinverted through inverse matrix mod ification lemma or partial matrix refactorisation technique. The present pa per proposes the use of base case Jacobians without reinversion or refactor isation and reforming only the right side vector in each iteration. A compa rative performance study between the proposed and the partial refactorisati on techniques regarding their on-line CPU time requirements and solution ac curacy has been made by conducting extensive simulation tests on a real pow er system for wider spectrum of practical cases involving topological chang es. (C) 2001 Elsevier Science Ltd. All rights reserved.