A novel theory for identifying transformer magnetizing inrush current

This paper introduces a novel theory which can be used to distinguish the transformer magnetizing inrush current from the real fault current. The theory and approach are presented, additionally, the simulation and test result are given. Compared with the conventional methods, such as the second harmonic restraint or the dead angle restraint, the novel method owns better characters in speed and reliability. At the same time, it can override some disadvantage of the conventional method.