非线性励磁控制中输出函数对系统性能的影响

发现在进行非线性系统的非线性控制设计时，状态方程中输出函数的选取对线性化以后系统状态方程的形式有很大的影响，进而影响到所设计的控制器性能。在此研究结果的基础上，改进了电力系统非线性控制器的设计方法，可以在统一的非线性控制设计框架下同时对多个状态量的性能指标提出要求，兼顾受控系统多个状态量的响应特性，使系统的动态性能和静态性能能够很好地协调，实现高性能的非线性控制。将改进的设计方法应用于发电机组的励磁控制，采用逆系统非线性控制原理设计了一种具有综合性能指标的非线性励磁控制规律。将所设计的多指标非线性励磁控制律用于单机无穷大电力系统的同步发电机组中进行仿真实验，其结果表明所提出的控制器不仅能明显地提高发电机的动态稳定性，而立能准确地将发电机的端电压控制在其给定值上运行，不会因受扰而发生偏移。

INFLUENCES OF THE OUTPUT FUNCTION ON THE SYSTEM PERFORMANCES IN NONLINEAR EXCITATION CONTROL

It is found that in the design of nonlinear control, selection of the output function of a nonlinear system can greatly affect the formulation of the linearized state space, which then affects the performance of the nonlinear controller. Taking this fact into account, a new output function for synchronous generator is formulated for the design of a high performance excitation control. The proposed nonlinear excitation controller can coordinate the dynamic and steady-state performance of the system well. Simulation results show that both the dynamic and steady-state performance of the synchronous generator with the proposed controller are greatly improved. Regulation of the generator terminal voltage and the stability of the generator unit are enhanced by the developed control. The proposed controller is valuable for industrial applications.