Authors’ summary: “A graph-theoretic decoupling technique is used with the aim of synthesizing a controller for a two-input/two-output linearized time invariant model of a synchronous-machine infinite-bus system. A state feedback control law is derived to accomplish the single- input/single-output decoupling action. Moreover, the control law also guarantees a desired location to all the critical eigenvalues of the decoupled closed-loop system. Thus, a satisfactory improvement of the dynamic performance of the decoupled system is also assured. A numerical example is carried out to illustrate the effectiveness of the proposed approach”.