中文摘要：

在以往研究300Mw汽轮发电机非线性特性的基础上，以常用的4种汽轮发电机为例，采用有限元方法，研究不同容量汽轮发电机负载非线性特性的共同特点。揭示了不同运行条件下4种汽轮发电机的负载非线性特性均与各自空载特性存在显著差别，而出现这种差别的原因在于大型汽轮发电机在负载运行时普遍存在铁磁饱和与磁场畸变非线性。研究结果可为建立电力系统非正常运行条件下发电机的非线性模型提供重要参考。通过2种机组的有限元计算结果与运行数据对比，证明结论的有效性。

英文摘要：

On the basis of former study of nonlinear characteristics of 300 MW turbine generator, four kinds of turbine generators with different capacities were taken as examples to study their common traits of load nonlinear characteristics by means of finite element method. The study reveals the prominent distinction between load nonlinear characteristics and respective no-load characteristic under different operating conditions. The distinction is due to the nonlinear characteristics of iron saturation and magnetic field distortion widely existed in large turbine generators under load conditions. The study results could be taken as the important references to establish nonlinear models of generators under abnormal operating conditions of power system. The results of two generators calculated by finite dement method （FEM） and practical operating data were contrasted to verify the conclusions in the paper.