Inversion of core magnetic track and remanent magnetic generation in switching transformer

In this paper, the author studied the magnetic motion of the core when the transformer is opened, derived the numerical calculation formula for the inversion of the magnetic track of the core when the transformer is opened, obtained the magnetic track and remanent magnetic track through reverse recursion and iteration, established the laboratory simulation platform of the transformer, and experimentally studied the magnetic track of the core under various opening conditions. The magnetic track after opening is different from the demagnetization curve. The recorded remanence can reach 92% of the saturation magnetic induction intensity, and the remanence can be minimized and the inrush current can be reduced by opening the secondary side load and then the primary side load when the transformer is out of operation.

Key words: transformer; Opening the brake; Magnetic trajectory; Residual magnetism; inversion