Novel method for evaluating the iron losses in SMC materials

Industrial systems comprehending reduced losses components are always more and more requested: the Standards push towards the improvement of the efficiency, and this forces to find new solutions to fulfill the constraints. For laminated steels appropriate methods to measure or estimate the iron losses are applied: Epstein frame or Single Sheet Tester (SST) for measurements, FEM simulation and analytical approach to estimate the penetration of the losses due to mechanical processing. In the case of the Soft Magnetic Composites (SMC) the test method normally adopted is the one with toroidal samples, which cannot give information about the losses distribution and the contribution due to processing. For this reason a new method based on a thermographic analysis is proposed: a contactless and non-destructive technique to evaluate the core losses and their distribution has been developed. The principle is based on the observation of the temperature changes distribution on the device surface; a deep elaboration of the temperature information allows to deduce the specific iron losses distribution. In this way it is possible to analyze in details the energetic behavior of the SMC and also to evaluate the impact of some process parameters (molding pressure, orientation etc.) on the losses; moreover the method could be applied to devices of every shape and dimension and adopted also outside the laboratories facilities.