Application results of the eigen-sensitivity theory of augmented matrix to small signal stability analysis of large power systems

This paper presents briefly the application results of the eigen-sensitivity theory of an augmented matrix to small signal and transient stability problems of the large Korea Electric Power Co. (KEPCO) system. First, the real parts of the eigen-sensitivity of the inter-area mode for changes in line parameters are found to be negligibly small. It may be concluded from this result that adding a new transmission line will not improve damping of the inter-area mode significantly. Second, the eigen-sensitivity of the inter-area mode for changes in line reactance is equivalent to controllability of the mode with TCSC as input. Hence, the lines having large sensitivity may be selected as the best candidates for installing TCSC for the purpose of improving damping of the inter-area oscillation. An H_∞ controller of TCSC installed at the selected lines damps successfully the inter-area oscillation. Thirdly, critical contingencies for transient stability are identified systematically by computing the modal synchronizing torque coefficient with use of eigen-sensitivity analysis of small signal stability model