【摘要】 对2007年版《IEEE Guide for AC Generator Protection》中失磁保护定值整定的几个问题提出不同意见。明确指出:发电机失磁故障必有滑差(s),其平均异步阻抗Xd(js)Xd(s=0),失磁保护中的阻抗元件下端定值为-Xd,已有足够余度,不应该是-(1.1～1.25)Xd;在P-Q坐标与R-X坐标的转换公式中,U值应由"失磁保护动作滞后于低励限制线(UEL)"原则来确定,不应主观选择0.95UN。更多还原

【Abstract】 Opinions different from the setting calculation of loss-of-excitation protection in IEEE Std C37.102TM-2007 IEEE Guide for AC Generator Protection are proposed. It is clearly and definitely pointed out that:when loss-of-excitation occurs,there must be slip,the average asynchronous impedance Xd(js) is much smaller than Xd(s=0),while the lower setting of impedance element is-Xd,which is far enough,-(1.1~1.25)Xd is not necessary; in the coordinates transformation formula between P-Q and R-X,the voltage U should be set according as the principle of "loss-of-excitation protection operates later than UEL (Under Excitation Limiter)" ,not to select 0.95 UN subjectively.更多还原