水轮发电机空载灭磁仿真研究

对水轮发电机空载误强励时磁场灭磁进行了仿真计算。针对用线性电阻、非线性电阻(包括氧化锌和碳化硅)灭磁，建立了不同的数学模型，并考虑了发电机空载特性的非线性，将空载特性用分析表达式近似表示，最后利用了MATLAB的Simulink工具。通过对三峡700MW水轮发电机的实例仿真，得出了灭磁过程中励磁电压、励磁电流的变化曲线，以及非线性电阻在灭磁过程中吸收的磁场能量和灭磁时间，并对比了在相同灭磁反压下用线性灭磁电阻的灭磁效果，为在已知发电机有关参数下设计和选取非线性灭磁电阻提供了依据。

Study on De-excitation Simulation of No-load Water Wheel Generator

The paper describes the simulation of de-excitation of no-load water wheel generators during mal-forced excitation. Various mathematical models for de-excitation with linear resistors and non-linear resistors, such as ZnC) and SiC, arc established In addition, the no-load characteristics of generators are expressed approximately by an analytic expression for facilitating the simulation. Finally, a simulation example of de-excitation for a water wheel generator of the Three Gorges Hydropower Plant with MATLAB-Simulink is given. The curves of the excitation voltage and current during de-excitation, and the absorbed energy of magnetic field and de-excitation time of non-linear resistors during de-excitation, are obtained. The de-excitation effect of linear resistors is compared for the same de-excitation in verse-voltage, providing a basis for the design and selection of non-linear resistors with known parameters of the generator.