This paper presents a new excitation controller design for multimachine power systems to augment transient stability and voltage regulation. To design the controller, zero dynamic design approach of feedback linearization is used which transforms the nonlinear power system model into a partially linear system, i.e., a reduced order linear system. Any linear controller design technique for reduced order linear system can be employed to enhance the stability of whole system provided that the internal dynamics of the systems are stable. In this paper, zero dynamic excitation control laws are derived for multimachine power systems whose performances are tested on 3 machine 11 bus two area system. Simulation results clearly indicate the performances of zero dynamic controller following large disturbances.