Comparison of iron loss calculation methods for soft magnetic composite

In order to increase torque and power density novel electrical machines often have 3D magnetic flux in soft magnetic materials. Therefore, an isotropic permeability is required. Soft Magnetic Composites offer this attribute and are predestinated for this application. To achieve higher power density less iron losses are useful. Hence, this paper presents different ways to calculate iron losses in soft magnetic composites. Starting with classical Steinmetz Equation, several further extensions are presented. These methods may be used for calculating iron losses during the optimization process to achieve higher efficiency. Calculating iron losses in electrical machines is time consuming. Furthermore, the iron losses cannot be separated from other losses. Thus, a ring core is used as a simplified problem to get meaningful results. Calculated losses using finite element analyses are compared with measurements from a test bench. The different methods are compared for sinusoidal and non-sinusoidal magnetic field strength concerning accuracy and required time.