Energy losses in Fe-based and Co-based amorphous materials

Abstract

It was shown in our experiments, that the dependence of excess losses on induction and frequency in amorphous materials (CoFeMnMo) 77 (SiB) 23 and in Fe 78 (SiB) 22 does not follow the dependencies resulted from Pry-Bean and Bertotti’s models. In this paper, the experimental results and their non-standard statistical analysis of the function describing the dependence of excess losses on frequency and induction are reported. The function was identified from a wide class of functions by means of an analysis of transformation of random variables, the so-called Box’s and Cox’s transformation. The function was so chosen, that the observation vector P, after Box–Cox transformation, had a normal distribution and its expected value was a linear function of B and f transformations, where B was the induction vector and f was the frequency vector. The logarithmic transformation for (CoFeMnMo) 77 (SiB) 23 material transforms P into P exc=0.553· B 1.51· f 1.41· ε′ and for Fe 78 (SiB) 22 one into P exc=1.23· B 2· f 1.25· ε′. The results may be useful for the analysis of magnetic circuits during design and when in use in real electrical equipment.