Affiliations: Department of Electrical and Computer Engineering, Concordia University, Montréal, PQ, Canada
Abstract: Two-dimensional (2-D) core loss measurements have low reproducibility and
repeatability, due to several errors such in data acquisition, sensing
systems and the magnetizer. The latter contributes to the variation in the
sample's flux density (B) under rotational magnetization. The variation in
B requires a reduction of the measurement region, stresses the power source,
lowers the circularity of B and modifies its locus. This variation is
analysed in four magnetizers, where sinusoidal distribution of the
magnetizing winding and increasing the yoke depth, are proposed. A deep yoke
will be shown to increase the magnetic loading of the sample, and mitigates
the variation in B in magnetizers with non-sinusoidal fields such as the
square tester. The location of B-coils can result to the overestimation or
underestimation of the measured B values; affecting the core loss.
Experiments showed a 14% (at ∼ 0.8 T) and 6% (at ∼ 1.6 T)
difference at two locations. B-holes also increase non-uniformity in the
sample; spiking of B and H at the hole regions. Numerical results will show
that it has minimal effects on B (< 1%), but the local increase in the
field (H) is in the order of 10$4$ A/m at saturation.
Keywords: Magnetic measurements, measurement errors, standards, rotational, core losses, single sheet testers
