Analysis of Formulas for Calculating the Magnetizing Inrush Current and Their Application for Modeling Purposes

This article presents an analysis of three formulas for calculating magnetizing inrush current. Initially, an evaluation of the correctness of these formulas was conducted using a digital power system model. Holcomb's and Specht's formulas demonstrated high accuracy of results, with errors up to 1%. Based on the conducted analysis, a method for verifying magnetizing inrush current for digital models using Holcomb's formula for determining residual flux is proposed. The results indicate that this method allows for calculating the current with an error of up to 7%. The error is attributed to the influence of no-load losses and the mutual induction of neighboring phases.