Abstract
This paper presents the methodology for design Takagi-Sugeno controller to mono-machine power system in order to study transient stability under severe perturbation. The nonlinear system is modeled and transformed on linear fuzzy model. Then, the design of Takagi-Sugeno regulator is derived from optimal control. The feedback gains are determined by linear quadratic instruction. This Technique is applied on test system. Important issues of transient stability and design are remarked.