大干扰下发电机间三阶非线性相关作用

相关因子在模式分析中占有重要地位,它反映了系统中各台发电机对某一振荡模式相关程度。相关因子大,相关程度就强;相关因子小,相关就弱。目前广泛采用的线性模式分析法虽然能提供有价值的线性化系统频域信息,但却忽略了系统非线性特性和系统固有模式之间相互作用的影响,不适合大干扰的情况。基于模态级数法3阶解析解,提出了大干扰下识别系统主导低频振荡模式的方法,确定了大干扰下对系统动态特性和稳定性影响最大的主导低频振荡模式,推导了3阶情况下的非线性相关因子,确定了非线性振荡的振荡源。并用Prony方法,验证了3阶相关因子和主导模式鉴别式的正确性和有效性。

Third Order Nonlinear Interaction Between Generators Under Large Disturbance

Participation factors play an important role in the modal analysis.They reflect the degree of the critical state variables interacting with one mode.The larger the factor is,the stronger the degree is.At present,linear modal analysis is used widely to provide valuable frequency domain information of linear systems.But it ignores the nonlinearity and the interaction of system inherent modes.On the basis of the third order analytical solution deduced by modal series method,an algorithm to identify the system critical inertial modes is presented under large disturbance.The third order participation factors are derived.Then the algorithm is validated using the Prony analysis.