基于正则形理论的电力系统2阶模态谐振的研究

应用向量场正则形理论对电力系统2阶模态谐振现象进行了研究，并对发生2阶谐振时系统动态特性和稳定性所受到的影响进行了分析。在模态空间，从识别主导低频振荡模式出发，通过分析模式间的非线性相关作用以及模式和状态变量之间的非线性相关性来确定由谐振所强烈激励的状态变量和相关发电机。8机系统的算例结果验证了在模态2阶谐振情况下系统非线性振荡将加剧、动态特性和稳定性将变化的正确性。该方法揭示了以往稳定分析中没有触及的一些新问题，得到了一些新观点，为更深入地研究电力系统内部的非线性结构特性奠定了基础。

Study on Power System Second Order Modal Resonance on the Basis of Normal Forms Theory

The second order modal resonance phenomena is researched and its effect on dynamics and stability of power systems is analyzed using the normal forms theory of vector fields in this paper. On the basis of identifying the dominant inertial modes, the critical state variables and related generators excited by the resonance are determined by analyzing the nonlinear interaction among modes and the nonlinear participation characteristic between the mode and the state variable in the modal space. Some new phenomena are revealed and some new points of view are obtained which cannot be touched by the classical stability analysis theory and method. It lays the foundation of the advanced research for nonlinear structure characteristic in power system. When the second order modal resonance occurs the system nonlinear oscillation may be intensified and the dynamic performance and stability will be affected. The calculation result from 8-generator system shows the correctness of the conclusion.