Experimental study of alternating magnetic field in laminated ferromagnetic core

Abstract

At engineering simulations of magnetic fields in ferromagnetic cores standard Preisach and Jiles-Atherton models are commonly used. At that a material magnetic properties are considered similar in all points of a core. However, the view of experimental hysteresis loops can differ from calculated even for materials with well-known magnetic properties, e.g. transformer steel. Experimental registration of hysteresis loops in characteristic zones of laminated steel core have revealed substantial discrepancy as in the loops view as in the field strength distribution in comparison with calculation results. Measurements at the frequency and field amplitude variation in order to reveal their influence on the magnetization process are conducted. The results obtained point to possible significant influence of magnetostriction effect on functioning of the ferromagnetic core. This influence can appear at frequencies of the core mechanical resonance and lead to changes in the core inductance and quality factor. The effect is relatively weakly pronounced at laminated steel core, but in some cases needs to be considered, e.g. if big size core operates at network frequency.