Takao Imagawa, Hitachi,Ltd.
Recent Energy-Crisis strongly demands the increase of the efficiency of motors. The effective answer is the usage of high-grade magnetic materials to the motor cores, however, the performance of magnetic materials in the cores are not clear because of the large demagnetization field. Knowing the intrinsic properties of magnetic core is essentially important to develop the core performance. H-coil method is useful way to measure the magnetic properties of sheets or foils through the demagnetizing field, but it is not clear that the method is applicable to the magnetic core shape. In this study, we made the measurement system model and analyzed the magnetic field by JMAG and revealed that the intrinsic magnetic properties were degraded from sheet.