A normalized energy function for fast transient stability assessment

New definitions of average angle centre and angle radius are proposed to develop a transient stability evaluation method which is fast and accurate for transient stability assessment. These two definitions are further developed to introduce two novel concepts, the normalized generators' equations of motion and normalized energy function (NEF), which in turn allow the assessment of critical clearing time (CCT) of system contingencies in a new approach. Case studies on the 10-generator New England, 17-generator Iowa and 50-generator test power systems are reported to verify the validity of the normalized energy function method. The method is very fast requiring only almost 0.5 s for the stability evaluation of contingencies in the 50-generator test system. (C) 2003 Elsevier B.V. All rights reserved.