汽轮发电机非线性特征的机理及其与运行条件的关系

发电机在临界失稳等非正常运行时，会出现比正常运行条件下更复杂的非线性特征，因而为进一步建立适合电力系统分析所用的发电机非线性模型，需要研究发电机非线性特征的机理及其与运行条件的关系。以有限元方法为工具，在对不同运行条件下的非线性特征进行定量分析基础上，一一分析磁场畸变、磁路饱和等非线性特征与功角、励磁电流等运行条件之间的复杂关系。研究发现磁场畸变导致的非线性程度不仅与功角有关，还与励磁电流及电枢电流有关；励磁电流漏磁通导致的转子轭部附加饱和效应同时受到励磁电流和功角的影响；而主磁路的饱和程度取决于端电压和功角的共同作用。通过模型机实测与有限元计算结果对比，说明结论可信。

Mechanism of Turbo-generator Nonlinear Characteristics and Its Relation to Operating Conditions

The nonlinear characteristics are more complex when turbo-generators operate under abnormal conditions. The mechanism of nonlinear characteristics should be studied in order to build the nonlinear generator model for the stability analysis of power system. Using finite element method, the nonlinear characteristics of generators under various conditions were quantitatively studied. The relationships between nonlinear characteristics and operating conditions were analyzed. It proposes that the magnetic field distortion is influenced by the power angle, the excited current and the armature current; the excited flux leakage caused iron saturation is affected by the excited current and the power angle; while the main flux saturation is determined by the terminal voltage and the power angle. The measured data and computational results of FEM were compared to verify the conclusions in the paper.