Transient analysis of synchronous machines

The paper reviews the transient theory of synchronous machines and sets out the two-reaction transformation in matrix notation. The advantages of the matrix-transformation theory and the Laplace- transform method are demonstrated. It is shown that Park´s transformation is equivalent to a change from a synchronous machine to a d.c. machine with brushes in the direct and quadrature axes and, in addition, an independent stationary zero- sequence circuit. An equivalent circuit is established for this d.c. machine (metadyne) and it is evident that transient fault-currents of a synchronous machine are intimately connected with those of a d.c. machine. Solutions are given for transient currents and torque.