A FAST AND EFFICIENT ACCURATE TECHNIQUE FOR CIRCUIT CONTINGENCY EVALUATION

The study of contingencies is an essential activity in the planning op eration and control of power systems. Contingency studies determine th e effects of line outage on the rest of the power system. For such con tingencies, an accurate power flow solution is not the preferred metho d to estimate the final bus voltages because of the prohibitive comput er time and cost involved. This paper presents a fast and efficient ac curate technique to evaluate the effect of line contingencies upon the system bus voltages. The complete Taylor series expansion of the noda l equations is used while retaining the non-linearity of load flow equ ations. A proposed function of load flow equations is introduced to re duce the size of load flow equations, and also to minimize the compute r time consumed in order to obtain final values of bus voltages. In th is technique, the contingency is simulated without disturbing the netw ork configuration, hence, the Jacobian matrix and its inverse are kept constant. This matrix is computed only once at the beginning of the s olution and then stored in the computer memory. An extensive study is carried out on four standard test systems to demonstrate the capabilit y of the proposed technique. (C) 1998 Published by Elsevier Science S. A. All rights reserved.