Solution methods for transient and dynamic stability

The transient stability study is used to examine the dynamic behavior of a power system following a disturbance. Transient stability programs have grown in the size of the power system under study, in the duration of the study, and in the magnitude of the disturbance. Each prime mover is represented by as few as two or as many as forty ordinary differential equations. These equations are coupled to a set of algebraic equations (two per node) which describe the network. Available programs frequently use explicit fixed step integration methods and the sequential solution of the differential and algebraic equations. Recent advances in solution methods have been directed toward implicit integration techniques and the simultaneous solution of the whole set of differential-algebraic equations. The transient stability problem, the unit models currently in use, and recent advances in solution methods are briefly reviewed. A dynamic stability program is described which incorporates comprehensive dynamic models of prime movers; the results of several experiments using this program are presented.