POWER LOSS IN ELECTRICAL STEEL UNDER ELLIPTICALLY ROTATING FLUX CONDITIONS

The power loss of electrical steel sheet given in the data sheets of t he steel manufacturers is related to linearly alternating flux conditi ons, measured with an Epstein frame or a single sheet tester, respecti vely. In the application of the material in electrical machines, we fi nd large areas with rotational flux conditions, i.e., in the T-joint r egion of three-phase power transformers or above the stator teeth of t hree-phase motors and generators [1]. The most general description of the magnetization process in this case is an elliptically rotating flu x [2]. The paper outlines the magnetic behavior of steel sheet under t hese flux conditions, and finally defines a simple method to predict t he total power loss under elliptically rotating flux from data measure d under linearly alternating and circularly rotating flux conditions o nly.