GENERALIZED EQUAL-AREA CRITERION : A METHOD FOR ON-LINE TRANSIENT STABILITY ANALYSIS

The method of generalized Equal-Area Criterion (GEAC) belongs to the class of the so-called direct methods of transient stability analysis of power systems. It can potentially be used for on-line stability assessment. The method is based on an exact mathematical transformation of the time invariant dynamical equations of an n-machine system into an equivalent single-machine-infinite bus (SMIB) system equation with time-varying parameters. Further approximations are made to assign appropriate constant values to the SMIB parameters, thus,enabling the use of a method version of the well-known equal-area criterion. An approximate stability index is then defined to yield the degree of stability/instability. The GEAC method is computationally very efficient. The GEAC stability index is simple and easily amenable to sensi tivity analysis. This make it potentially attractive for online determination of preventive control actions. The GEAC method was originally developed in 1984-85 in Europe by the author, then at Brown Boveri, Switzerland. The paper Offers an explanation of the GEAC method including its recent generalization to cover a wider range of faults causing system transients. Some test results are pre- sented. Potential applications of the GEAC method for on-line transient stability assessment are discussed.

GENERALIZED EQUAL-AREA CRITERION : A METHOD FOR ON-LINE TRANSIENT STABILITY ANALYSIS Keywords:

Power system stability , direct stability analysis , on-line transient stability , dynamic contingency analysis