Magnetic field and loss analysis in an apparatus for the determination of rotational loss

Abstract

The magnetic field and loss in an apparatus for the determination of magnetic properties of electrical steel under rotational flux conditions using field sensing coils (H-coils) is numerically analyzed by means of finite-element calculations in order to improve the accuracy of the apparatus. The method considered here is based on the determination of the field quantities and makes use of square-shaped samples and an air gap between the pole faces and the sample. The influence of various parameters is studied. The errors in field strength and loss decrease with decreasing gap, but for small gaps it is difficult to obtain circular rotational flux under sinusoidal primary voltage conditions. Furthermore, two different concepts of the determination of rotational loss are considered.