Modeling of iron-loss components of grain-oriented silicon steel for accurate calculation of core losses of power and distribution transformers

Abstract
Accurate estimation of iron-loss components of grain oriented silicon steel plays an important role in accurately predicting the core loss performance of power and distribution transformers. Existing practice among design engineers is to approximate the material iron loss performance by a simple curve-fit, like a polynomial. This paper presents the development of an improved analytical model which consists of terms that explicitly represent loss components contributing to the total iron loss of the transformer core material. These are expressed in terms of the operating flux density, frequency, and lamination thickness. Not only is the developed model simple and practical, but it also provides transformer design engineers with accurate understanding of the behavior of each loss component. The results presented here demonstrate the excellent accuracy resulted from using the model in calculating the transformer core loss performance at the design stage.