Eddy Current Loss Estimation of Edge Burr-Affected Magnetic Laminations Based on Equivalent Electrical Network—Part II: Analytical Modeling and Experimental Results

Abstract

In Part I of this two-part paper, fundamental concepts of interlaminar fault and its consequences on magnetic cores were presented. An equivalent configuration, which was proved by FEM modelling, was proposed for magnetic cores with interlaminar fault. In this Part II paper, based on the equivalent configuration of the core and equivalent circuit of eddy current path, an analytical model is developed to estimate eddy current power loss of magnetic cores with interlaminar faults in a wide range of magnetizing frequency. Important factors, such as skin effect, nonuniform flux density distribution, complex relative permeability and nonlinear relation of B (H), which are often neglected in the literature, are highlighted. Packs of two, three, and four Epstein-size laminations of conventional grain oriented were shorted together artificially to measure the extra power loss caused by the interlaminar fault and support the analytical modeling. It was found that in the magnetic cores affected by interlaminar fault, the skin effect is a determinant factor in the magnetic properties determinations, even at low frequencies.