| 摘要 |
The invention relates to a device and a method for determining the static B-H characteristic, magnetic induction - intensity of magnetic field, in ferromagnetic materials, with applications in electrical engineering. According to the invention, the device comprises a magnetic circuit in which one of the external sides includes a piece (4) the B-H characteristic of which is to be determined, the other sides (1, 2, 3) of the magnetic circuit being made of materials with known B-H characteristics, in the center of the circuit the sides (2 and 3) forming a medial yoke interrupted by an air gap, two coils (5, 6) placed in the two windows of the magnetic circuit wherethrough the currents iand ipass, a board with Hall probes (10) placed in the air gap of the medial yoke, the probes (10) being equally spaced along the air gap, so that from the sum of the transverse components of magnetic inductions detected by the said probes (10), the magnetic flux in the medial yoke results as null. The method, as claimed by the invention consists in supplying the second coil (6) with a current ihaving certain values with an ascending pitch Δ i, after which the value of the current iin the first coil (5) for which the magnetic flux in the medial yoke is null is to be found to obtain a string of current pairs of the two coils (5 and 6), while, for determining the B-H characteristic of a piece (4), the first pair of currents is taken, the magnetic field and flux are determined, where, supposing that the relation B-H starts linearly from the origin, with a slope μ, the value of the slope μfor which the flux is null is found, after which the maximum value of the magnetic induction in the piece (4) is determined, the B-H characteristic being described by the line of the slope μ, the slope being determined using the secant method, after which the procedure is continued, to finally obtain the linear B-H characteristic by portions. |
