Distance Measures and Coherency Recognition for Transient Stability Equivalents

Existing methods for transient stability equivalents all lack a means of drawing a consistent boundary between the equivalized area and the area represented in detail. In most methods, it is assumed that the generators equivalized are coherent. However, no simple method to identify them has been offered, which does not require a transient stability study of the entire system. A method using distance measures to draw boundaries and pattern recognition concepts to identify coherency is presented. Computation required is minimal. The method is incorporated in a computer program which is a useful tool for transient stability studies in power system planning.