According to the international standard IEC 60404–2:1996 + A1:2008, the magnetic characterization is only considered compliant if the magnetic polarization applied to the magnetic sheets under test has a sinusoidal waveform. The purpose of this study is therefore to propose a new approach to generate a sinusoidal magnetic polarization at the standard mains frequency of 50 Hz.
The method proposed in this paper is very simple. It is based solely on the use of a sinusoidal power supply and a negative resistor. The latter consists of an operational amplifier, two identical precision resistors and one power resistor. The negative resistor’s role is to compensate for the voltage drop in the Epstein frame.
This paper also presents an experimental validation carried out on an Epstein frame with grain-oriented silicon steel sheets. The obtained results confirm the effectiveness of the proposed method for generating a sinusoidal magnetic flux density, thus guaranteeing an accurate characterization of the sheets.
Given the advantages mentioned above, the proposed method can be easily implemented in the laboratories for a magnetic pre-characterization of the magnetic materials.
Compared to existing methods in the literature, the proposed method is distinguished by the absence of the feedback loop. In terms of performance, it has several advantages: it is very simple to implement, less expensive, requires less equipment and offers remarkable efficiency.
