互联非线性系统反馈主导控制设计方法及汽门开度控制应用

摘要

分析了电力系统非线性的数学性质,指出电力系统非线性是一种有界非线性。在此基础上,将反馈主导方法(feedback domination method, FDM)引入多机电力系统非线性控制。该方法与反馈线性化方法不同；反馈线性化方法是通过反馈将原非线性系统转化为线性系统,反馈主导方法则是通过反馈将原非线性系统转换为特定形式的非线性系统,该特定形式的非线性系统的动态由反馈引入的非线性部分主导。以多机系统非线性汽门控制问题为例,设计了反馈主导非线性汽门控制器,该控制器仅包含本地量测量,易于实现。数值仿真表明,多机系统反馈主导非线性汽门控制器可显著提高电力系统暂态稳定性。%Mathematical characteristics of power system nonlinearity are analyzed. It is shown that the nonlinearity between generator output power and node voltage is a kind of bounded nonlinearity. According to the bounded nonlinearity, we introduce the feedback domination method (FDM) for controlling the nonlinear multi-machine power systems. Being different from the feedback linearization method (FLM) which transforms a nonlinear system into a linear system through nonlinear feedback, FDM transforms a nonlinear system into another nonlinear system with a particular form through nonlinear feedback. The dynamics of the transformed nonlinear system is dominated by the nonlinear part in the feedback loop. As an example, feedback domination method (FDM) is applied to design the nonlinear turbine valve control in multi-machine power systems. The nonlinear valve control law constructed for generators only includes local measurements, so that it is easy to be implemented. Numerical simulations demonstrate that the nonlinear valve control law based on FDM effectively improves transient stability in power system.