三峡水轮发电机组灭磁方案研究

对三峡机组可能选择的三种灭磁方案（线性电阻灭磁，氧化锌非线性电阻灭磁，碳化硅非线性电阻灭磁）进行了探讨，仿真比较了三者在大电流和小电流下的灭磁情况，并重点研究了两种非线性电阻灭磁方案在三峡水轮机组上的灭磁情况。结果表明，三峡机组若采用线性电阻灭磁，至少需要15s以上的灭磁时间，这无法起到保护机组的作用；而采用非线性电阻灭磁，灭磁时间大约是2-3s，因此非线性电阻适用于三峡机组的灭磁保护。根据研究结果，在三峡电站首期发电机组中，建议采用磁化硅非线性电阻灭磁系统。

RESEARCH ON DE-EXCITATION PROJECTS FOR POWER GENERATING SETS IN THREE GORGES HYDROELECTRIC POWER STATION

Three kinds of de-excitation projects, i.e., linear resistor, ZnO non-linear resistor and SiC non-linear resistor, which may be chosen for power generating sets in ThreeGorges Hydropower Station are discussed. The de-excitation situation of the three projects under heavy field current and low field current are compared by simulation, and the de-excitation situation of hydroelectric sets in Three Gorges Hydropower Station by two kinds of non-linear resistor are emphatically researched. The research shows that when de-excitation iscarried out by linear resistor, the least time for de-excitation is 15 seconds or longer, thus, the generating sets cannot beprotected; when non-linear resistors are used in de-excitation for same generating sets, the time for de-excitation is 2-seconds, therefore, the non-linear resistors are suitable to the de-excitation system for hydroelectric sets in Three GorgesHydropower Station and it is suggested to apply SiC non-linear resistor de-excitation system to the firstling generating sets of Three Gorges Hydropower Station.