9530679 Bose The periodic analysis of the security of a power system is done to ensure the ability of the power system to withstand contingencies. Such on-line analysis requires, in principle, the checking of the effects of hundreds of disturbances on the power system. The checking of the post-disturbance steady state of the power system for these contingencies requires only the handling of algebraic equations (albeit in large numbers and with nonlinearities), and such static security analysis (SSA) is now routinely done on-line. However, checking for instabilities during the disturbance itself requires the handling of nonlinear differential equations in addition to the algebraic equations, and the computation required for this dynamic security analysis (DSA) is about three magnitudes higher than that for the SSA. Thus, on-line DSA is still in its development stage although experimental prototypes have been implemented. This proposal is for examing the important aspects of this problem and developing new approaches for its solution. ***
