Determination of AC magnetic power loss of electrical steel sheet: Present status and trends

A brief survey of the status of work in the higher induction and frequency ranges is given and recent papers on the measurement of rotational losses are reviewed. The determination of the magnetic losses in alternating fields is considered, in partucular regarding the performance of those magnetic circuits most widely used in loss measurements. New and revised data contribute to the elucidation of the systematic errors of the Epstein square. The Epstein samples and plate samples, both of various materials, were used for measurements with single sheet testers, whereby the field strength was determined both from the magnetizing current by means of a precision resistor and direct, using field sensing coils. From these results conclusions for the appropriate value of the effective magnetic path length can be drawn. The electric power measurement particularly as regards digital procedures, calibration and uncertainties is briefly discussed.