Absfracf-A controller of the synchronous generator represented by a third order model is studied in this paper. In addition to the base case, transient responses for the other cases with different constraints, operating conditions, and disturbances are dseussed. Results demonstrate that the feedback gains obtained from the base case are still applicable to the other cases, and the controlling performance is quite satisfactory. The transient response of only conventional terminal voltage feedback is also computed for comparison.In this research, state and control parametrization approach using piecewise constant functions with different timeinterval is proposed. With the parametrization, the optimal control model is first formulated as algebraic equations. Then, the algebraic equations are solved using the nonlinear programming technique.