Preisach Model for Calculating Transient Processes in a Measuring CT

A description of the mathematical model of the measuring current transformer for relay protection is presented, taking into account the nonlinearity of the magnetization characteristic and hysteresis in the magnetic circuit using the Preisach model. Based on the created CT model, the transient process was calculated when the amplitude of the periodic component of the primary current and the residual induction in the magnetic circuit varied, and a qualitative description of the transformer saturation process was given. It is shown that the operating range of the CT has a lower limit caused by magnetic processes in the Rayleigh region.