变压器差动保护中平衡系数对差动门槛的整定影响

Influence of balance coefficients of transformer differential protection on setting of differential current shreshold

数字式变压器差动保护用平衡系数代替了传统保护的平衡线圈。在平衡系数整定中,基本侧选择不同,将直接影响差动保护最小动作电流(差动门槛)的整定。探讨了目前存在的4种基本侧选择方式,并提出了差动门槛整定与基本侧的对应关系,以便更合理地整定不同保护装置的差动门槛。

Different from traditional protections using balance winding, the digital transformer differential protection uses balance coefficients. In the balance coefficient setting, the selection of reference side of the transformer exerts direct influence on the setting of the minimum operating current （differential current threshold） of the differential protection. Four methods for selecting the reference side are discussed, and the corresponding relation between setting of the differential current threshold and the reference side is proposed to make a better setting of the differential current threshold for various protection devices.