The stability of electric power system has been being focused for a long time toprevent a power system from losing synchronism after sudden fault ， researchers have done much work and got many accomplishments this paper applied the direct feedback linearization ( dfl ) technique on the power system ， a strong nonlinear system simulation results by matlab proved this method efficiency main works and results are as follows ： this paper compared some existing methods in excitation control ， fast valve control and coordinated control respectively , analyzed the developments and actuality of nonlinear control research in brief , illustrated why ransient stability could be greatly improved by using the fast valve control in chapter 3 ， indicated the importance of coordinated control farther this paper introduced the inverse system theory , based on which ， discussed the dfl theory , pointed out which had consistency with the inverse theory , expanded the dfl theory combined the idiographic model equations ， made which adapt to the model of a single machine - infinite bus power system this paper referenced abundance articles and educed a set of equations ， which could describe the dynamical process of excitation and fast valve control for synchronous generators in the equations ， there were several very important parameters of power system - - rotor angle ( ) ， rotor speed ( ) ， generator q axis voltage ( eq ) ， transient voltage ( e ' q ) ， active power ( pe ) ， mechanical input power ( pm ) ， valve opening ( ) ， generator terminal voltage ( vt ) ， based on the model ， nonlinear coordinated controller and terminal voltage optimal controller have been designed by using the expanded dfl theory and lq optimal control theory the simulation results showed that the controller could keep power system transiently stable under the effects of a symmetrical 3 - phase short circuit fault ， which achieved better postfault regulation compared with another two routine methods ， one is the proportion excitation controller and proportion fast valve controller , the other is the proportion excitation controller and the optimal fast valve controller , which could exert good performance when met 1ittle disturbance either 在介绍逆系统理论的基础上，详细介绍了dfl理论，通过比较阐明了dfl理论其本质是逆系统方法的一类，并结合具体课题推导出的模型方程将dfl理论进行了扩展，使之适应于电力系统这个强非线性对象。通过参考大量的书籍文献推导出一套实用的可将大型汽轮发电机励磁与汽门综合起来进行控制的模型方程，此模型方程涵盖了电力系统中特别引人注目的几个量- -转子角、转子转速、发电机q轴电势eq 、暂态电势e ' q 、有功功率pe 、机械功率pm 、汽门开度、机端电压vt ，在此基础上建立了实用的电力系统简化的数学模型，并将扩展的dfl理论应用于此模型系统，结合线性二次型最优控制理论设计出大型汽轮发电机的非线性综合控制器及机端电压最优控制器，通过仿真实验与采用常规的按电压偏差进行调节的比例式励磁控制器+汽门比例控制及采用常规的按电压偏差进行调节的比例式励磁调节器和基于二次型性能指标设计的最优快控汽门(考虑发电机的饱和因素)进行了对比，证实了采用此种控制器可以有效地提高电力系统的暂态稳定性，并且在电力系统遭受小干扰时同样具有良好的调节性能。
