利用扩张状态观测器将原来的非线性系统变换成线性系统 ,然后用状态 PI控制器的设计思想设计了非线性状态 PI控制器 ;并将其用于发电机励磁控制 ,以解决电力系统的强非线性和不确定性问题 ,避免了反馈线性化非线性励磁控制由于数学模型的误差而影响控制器性能的缺点。所得控制规律与系统运行点和网络结构完全无关 ,同时控制器结构简单。仿真计算表明 ,非线性状态 PI励磁控制器对系统运行点和网络结构变化具有良好的适应能力 ,可以有效地改善系统的稳定性 The extended state observer is used to transform the original nonlinear system into a linear system. Then, a nonlinear PI controller is designed with the design idea of ​​the state PI controller. The PI controller is used to control the generator excitation to solve the problem of strong power system Nonlinear and uncertain problems, to avoid the feedback linearization of nonlinear excitation control due to mathematical model errors affect the controller’s shortcomings. The resulting control law has nothing to do with the system operating point and the network structure, and the controller structure is simple. The simulation results show that the nonlinear state PI excitation controller has good adaptability to the changes of system operating point and network structure, and can effectively improve the stability of the system