Transformer magnetizing inrush current restraining and differential protection matching method

The invention discloses a transformer magnetizing inrush current restraining and differential protection matching method. The method comprises the following steps of S01 switch closing time self-learning, S02 switch opening information recording, S03 calculation of a voltage phase angle alpha generated at the opening moment, S04 calculation of a voltage phase angle generated at the switch closing triggering moment, S05 closing execution, S06 calculation of an A-phase voltage phase angle gamma generated at the switch closing moment and S07 inrush current latching adjustment, wherein in the S07, inrush current logic adjustment is conducted according to the inrush current restraining effect. According to the transformer magnetizing inrush current restraining and differential protection matching method, the magnetizing inrush current restraining effect of current closing can be evaluated according to the phase angle at the actual switch closing moment and an optimal closing phase angle worked out theoretically, differential protection inrush current latching criteria can be adjusted according to the restraining effect, and the reliability and the sensitivity of transformer differential protection can be improved easily.