Iron Losses In Magnetic Materials Research Articles

Iron loss evaluation of magnetic materials excited by a SiC inverter with a Schottky barrier diode wall-integrated trench MOSFET

This study examines the impact of the different diode characteristics on the magnetic hysteretic and iron loss properties of a conventional non-oriented (NO) silicon steel sheet core under silicon carbide (SiC) inverter excitation. We compared the magnetic properties of the magnetic core excited by the inverter using the developed Schottky barrier diode (SBD) wall-integrated trench MOSFET (SWITCH–MOS), which has a low on-voltage Von diode, with those excited by the inverter using a conventional U-shaped trench gate MOSFET (UMOS), which has a body PiN diode with high Von. This study shows for the first time that the shape of the minor loop and iron loss properties depends strongly on only the diode characteristics in the inverter. The iron loss of magnetic materials excited by the SWITCH–MOS inverter with the low-Von diode (i.e., the built-in SBD) was less than that in the case of using the conventional UMOS with a high-Von diode (i.e., the body PiN diode). That is, the SWITCH–MOS with built-in SBD can reduce not only the switching loss, but also the iron loss in magnetic materials such as motor cores.

Predicting Iron Losses in Laminated Steel with Given Non-Sinusoidal Waveforms of Flux Density

In electrical machines, iron losses are essential for electromagnetic and thermal designs and analyses. Although many models have been proposed to predict iron losses in magnetic materials, the calculation of iron losses under non-sinusoidal excitations is still an open field. Most works concern the influences of the value, the change rate or the frequency of flux density in the frequency domain. In this paper, we propose an engineering model for predicting loss characteristics with given waveforms of flux density in the time domain. The characteristics are collected from the knowledge of the iron loss in a laminated ring-shaped transformer. In the proposed model, we derive mathematical formulas for exciting currents in terms of flux density by describing the function methods through multi-frequency tests with sinusoidal excitations. The non-linearity of the material is interpreted by branches of conductances accounting for hysteresis and eddy-current losses. Then, iron losses are calculated based on the law of conservation of energy. An experimental system was built to evaluate the magnetic properties and iron losses under sinusoidal and non-sinusoidal excitations. Actual measurement results verify the effectiveness of the proposed model.

二方向性けい素鋼板の２次元磁気特性

Recently, the quantities of energy consumed by electrical machines have been increasing every year. As a result, it has become important to find new ways of saving energy, and to develop highly efficient electrical machines. The efficiency of an electrical machine depends on the iron loss of magnetic materials. We measured the two-dimensional magnetic properties of a sheet of double-oriented silicon steel with excellent properties. From the data thus obtained, we calculate the permeability tensor, the coercive force, and the iron loss, and compare the properties with those of a single-oriented silicon steel sheet.

Iron losses in magnetic materials with six-step and PWM inverter supply (induction motors)

The energetic behavior of two samples of soft magnetic materials fed by inverters has been studied. The authors dealt with the increase of the iron losses due to a nonconventional voltage supply. Six-step and PWM (pulse width modulated) inverter output voltages have been selected as the excitation waveforms for the samples under test. Extensive experimental results of high-quality grain-oriented silicon steel and amorphous-alloy-wound core samples are presented. A detailed description of the testing procedure is shown. The results are quite informative and quantify the iron-loss increase with nonsinusoidal supply in comparison with the results obtained by the standard tests (sinusoidal supply and Epstein method). The comparison can give useful indications to electromagnetic-device designers about the derating factors for the different magnetic materials that have to be used in designing devices fed by static power sources.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>