Measurement of the Vector Magnetic Property of Electrical Steel Sheet Under Triaxial Stress

The magnetic properties of iron cores of electrical machines can be affected by complex stress, which influences the B-H curve and the magnetic losses. This article proposes a measuring method by which the 2-D magnetic properties of electrical steel sheets are measured through a cross-shaped rotational single-sheet tester (RSST) under triaxial stress conditions. Three stress-loading systems are installed in three perpendicular directions. A novel square-shaped vector B-coil is designed to overcome the deformation of B-coils caused by stress. Furthermore, an array of three vector H-coils and a linear fitting method are used to measure the magnetic field strength H. The waveform of magnetic flux density is controlled through a feedback system. Measurements under 1-D and 2-D supply conditions are successfully performed on nonoriented specimens under such complex stress.