水轮发电机新型灭磁方案

New Method of De-excitation for Hydraulic Generator

大型水轮发电机通常采用的非线性电阻灭磁的方法,对灭磁开关的开断弧压要求愈来愈高,其机理是要求开关开断时,磁场绕组的自感电势大于非线性电阻的残压。本文首先介绍了用电容器灭磁的原理,然后解释了利用R,L,C串联谐振时产生高电压,来迫使非线性电阻投入运行的新方法,降低了对灭磁开关开断弧压的要求,并对此进行了仿真,证明了它的可行性。

Requirement for arc voltage during opening of field breaker is higher and higher, for de-excitation with varistor, generally adopted for large hydraulic generator. In fact, E.M.F of field winding is required higher than threshold of varistor during opening of field breaker. In the paper the principle of de-excitation with capacitors is introduced. Then high voltage produced by R,L,C series oscillation is used to forcing varistor put into operation ,which decreases the requirement for opening arc voltage of field breaker. A simulation is completed to confirm it availability.