The Impact of Rotating Field on Core Loss Estimation in Electrical Machine Laminations

An investigation and analysis of core losses in rotating AC machines shows that the stator is subjected to different types of flux density including pulsating and rotating. The rotating flux can be elliptical or circular. This paper describes the influence of different flux patterns on core loss estimation. Three different machines are simulated to calculate the zones of rotating flux density in the stator cores of these machines. Experimental tests are executed using a new magnetizing circuit based on an electromagnetic Halbach array which is able to generate different types of flux patterns with different frequencies. Furthermore, the percentage error made by assuming all flux is pulsating is calculated.