变压器差动保护涌流制动原理分析

空充误动是变压器差动保护的一大难题，现有的涌流制动原理主要是二次谐波和波形对称。文中深入分析了这2种原理之间的内在联系，指出不同的转角方式对保护可靠性产生的影响。传统的Y侧转换方式下，两相涌流之差可能导致二次谐波减小，波形趋于对称，这2种原理均可能误动；D侧转换方式下，三相涌流将互相影响，难以确定谐波制动的比例。

Analysis of Inrush Restraint Theory for Transformer Differential Protection

According to the general inrush restraint theory, it is hard for the current differential relay of transformer to overcome the mal-operation when the transformer is energized. Based on an in-depth analysis of the relationship between the secondary harmonic restraint theory and wave symmetry theory, it is pointed out that the reliability of the protection is influenced by the type of phase compensation. When the phase is compensated for at the star side in the conventional way, the decrease of two-phase inrush may result in the reduction of the secondary harmonic in the differential current. If the wave of differential current seems to be symmetrical, the above two inrush restraint theories may operate incorrectly. When the phase compensation is done on the delta side, it will be hard to confirm the ratio of the secondary harmonic restraint.