IDENTIFICATION OF GENERIC BIFURCATION AND STABILITY PROBLEMS IN POWER-SYSTEM DIFFERENTIAL-ALGEBRAIC MODEL

Based on the structurally represented power system differential-algebr aic model and its Jacobian matrix, this paper develops a much more com plete and systematic classification of the types of bifurcation and st ability problem in the power system model. It is theoretically shown t hat bifurcations can not occur due to the row dependence of the networ k Jacobian matrix (causality matrix) associated with the rows of the a ctive and reactive power balance equations at a single bus or at a sub set of buses, resulting in several of the classified bifurcations bein g non-generic. The generic types of bifurcation and instability proble ms are then identified: static bifurcation, dynamic bifurcation, loss of causality, and loss of single-machine stability; the later two are further shown to be very improbable. This paper also proposes an equiv alent test for static bifurcation - static/algebraic bifurcation test whose advantages are disclosed. The identification of generic bifurcat ion and stability problems in power systems provides the foundation of the further study on static and dynamic voltage-angle stability probl ems.