It is mainly used to protect all kinds of interphase short circuit faults in the winding of double-winding or triple-winding transformer and its lead line, and also can be used to protect single-phase turn to turn short circuit faults of transformer. Differential quick-break protection, in order to prevent the differential protection in high short-circuit current level, due to the current transformer saturation of the high order harmonic increase, resulting in a great brake torque and make the differential protection reject; When the short-circuit current reaches 4-10 times the rated current, the quick-break element exits quickly Differential protection performance is very good, can instantly remove the full range of fault, generally only used for component protection, such as transformers and generators. The principle is to compare the magnitude and direction of the current on both sides of the element.
