Influence of air gaps between grain-oriented steel sheets on losses in the magnetic system

This paper presents results of investigations of the influence of air gaps in GO steel sheet inserts on magnetic losses. Classical iron loss measurements were performed using a single strip tester to magnetize material samples at 50 Hz. The samples included air gaps of various thickness and it is found that their presence led to the increase the losses up to 30%. It is concluded that if GO steel inserts are to be used in a magnetic system of an electrical machine, the sheets must be properly connected to reduce the effect of air gaps and thus to increase the overall performances of the machine.