On the practical relevance of rotational magnetisation for power losses of transformer cores

Abstract The paper discusses the relevance of rotational magnetisation (RM) for power losses in laminated transformer cores. Experimental results are given for the local distribution of the loci of the induction vector B and the magnetic field vector H . Further, typical local amplitude ratios e for magnetisation in transverse direction and regional building factors are shown for defined regions of the core. An approximate estimation indicates that about 13% of the total building factor can be attributed to RM phenomena, including effects of flux distortion.