带阻尼绕组的水轮发电机空载灭磁仿真

对转子带阻尼绕组的空载水轮发电机误强励时的灭磁进行了仿真计算。针对用非线性或线性电阻灭磁，以及用近似的分析表达式来考虑发电机空载特性的饱和，建立了微分方程组的数学模型，并利用差分法的数值计算，对三峡水电厂700 MW水轮发电机灭磁的实例进行仿真，得出了灭磁过程中磁场电流、电压和d轴阻尼绕组电流的变化曲线,以及灭磁时间和灭磁电阻、磁场绕组、d轴阻尼绕组吸收的磁场能量，并且给出了灭磁过程中空载发电机端电压在d,q轴分量的变化曲线。重点评价了水轮发电机转子阻尼绕组在灭磁过程中的作用。

A De-excitation Simulation of No-load Hydro-turbine Generator with Damping Winding

This paper presents the simulation results of de-excitation of a no-load hydro-turbine generator with damping winding on the rotor during mal-forced excitation happens. Differential equations are established for the mathematical model of deexcitation for the hydro-turbine generator with linear or nonlinear resistor considering the saturation of no-load characteristics expressed by approximate analytic expressions. Finally, an example of de-excitation simulation of a 700 MW hydro-turbine generator of the Three Gorges Hydropower Plant is presented with difference method for numerical calculation. The curves of the field current and voltage and the damping winding current on d-axis are obtained, and the de-excitation time, magnetic energy absorbed by de-excitation resistor, field winding and damping winding on d-axis are also obtained. The curves of voltage components on d-axis and q-axis of the no-load hydro-turbine generator during de-excitation are also given. The role of rotor damping winding of a hydro turbine generator in de-excitation is evaluated.