ELECTROMAGNETIC ASPECTS OF ELECTRICAL MACHINES Available to Purchase

The development of electrical machines is nowadays closely related to the knowledge of the electromagnetic fields throughout the different parts of a machine. Although a machine is often of complicated geometrical structure and of different, mostly nonlinear materials, modern numerical methods and the related software allow calculation of the fields in 2D models and several 3D cases precisely enough in order to derivate from them quantities like energy density distribution, the torque behaviour and characteristics like load and no load. The paper will at first compare numerical methods suited for electromagnetic field calculation in electrical machines. The following topic deals with adaptive mesh generation playing an important role to save computer memory and cpu time. Then examples like a Switched Reluctance Machine, an Asynchronous Machine and a Stepping Motor are shown concerning the results of field calculation. It is shown that anisotropy may have to be taken into account, and finally it is shown that field calculation enables the shape optimization of a machine.