BH Curve Extrapolation Method for Semi-Infinite Silicon Steel Sheets Model Based on Vector Magnetic Circuit Theory

The fundamental magnetization curve, or BH curve, represents the relationship between magnetic flux density B and magnetic field strength H when H varies periodically, typically determined through experimental measurements. This study presents an innovative method, grounded in vector magnetic circuit theory, to extrapolate BH curves across various frequencies from a known BH curve at a specific reference frequency. Building on the semi-infinite model of the silicon steel sheet, the expressions for reluctance and magductance, along with their relationship to frequency, are derived by applying electromagnetic field theory and vector magnetic circuit theory. Using a known BH curve at a specific frequency as a reference, the relationship between H and B can be calculated based on Kirchhoff’s magnetic circuit law of vector magnetic circuit theory. Finally, the feasibility and validity of this BH curve extrapolation method is confirmed through experimental results.