Development of simplified evaluation method of iron bosses in actual stator cores of rotating machines

This paper deals with a simplified iron loss evaluation method for actual stator cores of rotating machines. It is well known that the magnetic properties deteriorate in constructed cores due to conditions stressed by riveting and welding in manufacturing process and punching and shearing in cutting process of the silicon steel sheets and so forth. As a result, the iron losses increase in comparison with one of the ideal materials assumed in designing, and the building factor becomes more than one. Thus, evaluation of core losses depending on stress becomes important to develop high-efficiency motors and actuators. However, at present, the evaluation of core losses in actual laminated cores of rotating machines has not yet examined fully. A difficultly exists in evaluation methods of the field intensity and flux density distributions in actual complicated core structures. In this paper, knowledge obtained in development of a simplified evaluation method of iron losses in actual stator cores of rotating machines is presented.