汽轮发电机小扰动特性及静态稳定性的时步有限元分析

Time-step Finite Element Analysis for Small Disturbance Characteristics and Static Stability of Turbo Generators

为了研究阻尼绕组和磁场饱和对汽轮发电机小扰动特性及静态稳定性的影响,分别采用经典派克(Park)方程模型与时步有限元(time-stepping finite element method,T-SFEM)模型,对发电机不同工况下发生的小扰动进行仿真计算。在此基础上,结合小信号分析法与普罗尼(Prony)方法,对比分析了不同模型下发电机小扰动过程的动态特性以及系统静态稳定性等相关问题。结果表明,在不考虑阻尼绕组与磁场饱和的情况下,2种模型所得的小扰动特性基本一致,而当计及阻尼绕组或磁场饱和作用时则差别显著;采用派克方程模型计算所得的静态稳定极限功角比时步有限元模型的计算结果偏大。研究结果为系统仿真分析提供了合理参考。

In order to research the influence of damping winding and magnetic saturation on dynamic characteristics of turbo generators and power system static stability,the small disturbance process under generator＇s various operating conditions was calculated using classic Park equation and time-stepping finite element method （T-S FEM） model respectively. On this basis,by combining the small signal analysis and Prony method,this paper compares and analyzes the result such as dynamic characteristics of generators in small disturbance processes and system＇s static stability between the different models. The results show that,without considering damping winding and saturation,the small disturbance characteristics obtained by different models were basically identical,however the difference was significant if they are considered,and the static limit angle calculated using Park equation model was larger than that using T-S FEM. The result provides reasonable reference for system simulation analysis.