大电机定子槽楔松动的危害及检测方法

大型发电机在长期的运行过程中,由于定子线圈的电流与定子槽内横向磁场的作用使得槽部线棒承受相当大的电磁力,定子槽楔长期在机械应力作用下会发生松动现象。定子槽楔发生松动会导致定子线棒在电磁力的作用下产生电磁振动,从而加剧定子线棒绝缘的机械磨损及槽内放电引起的绝缘腐蚀,这直接威胁着大型发电机的安全运行。文章综述了大电机定子槽楔的作用和大电机中松动槽楔的存在可能导致的危害,介绍了国内外多种检测槽楔松动的技术和方法,并分析了它们的优缺点,最后重点介绍了本实验室在槽楔松动检测方面的最新成果。

Dangerous Results and Detection Methods of Loose Stator Slot Wedges of Large Generator

After a long term running of large generator,the stator slot wedges would become loose under electromagnetism force as a result of the compositive effect of stator winding current and the magnetic field across through stator slot.Stator bars may get into vibration fiercely caused by the electromagnetic force due to the existence of loose wedges in large generators,which would accelerate the deterioration of the insulation system,even making the generators step into calamity ultimately without any treatment.This paper discusses some possible dangerous results of large generators caused by loose stator slot wedges and the detection methods or machines of loose slot wedges over the world.Moreover,a new loose slot wedge detection system developed in our lab is introduced at the end.