High Iron Loss Research Articles

Evaluation of experimental permanent-magnet brushless motor utilizing new magnetic material for stator core teeth

We prepared motors with experimental cores using a soft magnetic composite and an amorphous metal and evaluated their performance. We measured the magnetic and motor characteristics, such as iron loss, when the new materials were used in the stator core teeth. The amorphous metal was found to have very high permeability and low iron loss, whereas the soft magnetic composite had low permeability and had a comparable iron loss as low-grade magnetic steel. The soft magnetic composite had the added benefits of being able to form a three-dimensional shape and having relatively low core loss in high frequency conditions. The magnetic properties we measured were able to predict the motor characteristics with high accuracy based on numerical and finite-element-method analysis.

BLDC motor stator and rotor iron losses and thermal behavior based on lumped schemes and 3-D FEM analysis

Many industrial applications refer to brushless DC (BLDC) motors applied at their thermal limits. Two cases related to the motor configuration lead to high possible iron losses and, consequently, to the necessary knowledge of the thermal behavior of the motor. Referring to the motor synchronous frequency: the first case corresponds to a relative low speed, but a high number of pole pairs (torque motors used in direct drive applications); the second case to a low number of pole pairs, but a high speed (mass storage applications, for example). The iron losses are a key issue since the considered frequencies are over the usual range of the known field of magnetic material vendor characteristics. Because the excitation flux and the slot geometry introduce high harmonic frequencies, rotor losses are a key issue of the investigation. This paper considers a torque motor with a high number of slots and high number of poles. The authors present two different methods to model the iron losses and the thermal behavior. The first method uses two lumped schemes: the first scheme permits us to determine the flux distribution as well as the stator, magnet, and rotor yoke iron losses. The temperature gradient distribution is computed using an original lumped thermal scheme of the motor. The second method uses finite-element method (FEM) analysis with a two-dimensional model for the magnetic behavior and a three-dimensional (3-D) model for the thermal behavior. A testing bench for a BLDC torque motor has permitted us to measure the iron losses at no-load generating operation and the temperature using thermal probes and infrared camera. Then, simulations and measurements results are compared to characterize the accuracy of the two methods. The two main interests of the presented work consist of: (1) the computation of the whole iron losses in the stator as well as in the rotor yoke and the magnets; and (2) the comparison of the thermal behaviors obtained with a thermal lumped scheme and 3-D FEM simulations.

Quantification of Stray Losses in a 75kW Induction Motor with Caged Bars

A study on the stray losses of a 75kW class caged induction motor is presented. Stray losses in the 75kW class induction motor are evaluated in this work using Finite Element Method analysis and measurement. It was found that the most of the stray losses are the high frequency iron loss of the rotor.

磁心の温度上昇による高周波鉄損計測システムの校正

磁心の温度上昇による高周波鉄損計測システムの校正

High frequency iron loss of sendust ribbons made by a rapid quenching method

Electrical Engineering in JapanVolume 109, Issue 4 p. 17-21 Article High frequency iron loss of sendust ribbons made by a rapid quenching method Kenji Ohmori, Kenji Ohmori Central Research Center, Sumitomo Mine Industry Inc., JapanSearch for more papers by this authorKen-Ichi Arai, Ken-Ichi Arai Research Institute of Electrical Communication, Tohoku University, Sendai, JapanSearch for more papers by this author Kenji Ohmori, Kenji Ohmori Central Research Center, Sumitomo Mine Industry Inc., JapanSearch for more papers by this authorKen-Ichi Arai, Ken-Ichi Arai Research Institute of Electrical Communication, Tohoku University, Sendai, JapanSearch for more papers by this author First published: July/August 1989 https://doi.org/10.1002/eej.4391090403AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Volume109, Issue4July/August 1989Pages 17-21 RelatedInformation

Iron nutrition and absorption: Dietary factors which impact iron bioavailability

Iron deficiency is widely observed worldwide, yet, paradoxically, iron is the most plentiful heavy metal in the earth's crust. Although absorption of iron from the gastrointestinal tract is strictly controlled, excretion is limited to iron lost from exfoliation of skin and gastrointestinal cells, customary and abnormal blood loss, and menses. Individuals highly vulnerable to iron deficiency have high iron needs, as during growth or pregnancy; high iron loss, as during marked hemorrhage or excessive and/or frequent menstrual losses; or diets with low iron content or bioavailability. Food iron is classified as heme or nonheme. Approximately half of the iron in meat, fish, and poultry is heme iron. Depending on an individual's iron stores, 15% to 35% of heme iron is absorbed. Food contains more nonheme iron and, thus, it makes the larger contribution to the body's iron pool despite its lower absorption rate of 2% to 20%. Absorption of nonheme iron is markedly influenced by the levels of iron stores and by concomitantly consumed dietary components. Enhancing factors, such as ascorbic acid and meat/fish/poultry, may increase nonheme iron bioavailability fourfold. J Am Diet Assoc 88:786, 1988.

急冷法により作製したセンダストリボンの高周波鉄損

急冷法により作製したセンダストリボンの高周波鉄損

High frequency iron loss of sendust thin ribbons made by a rapid quenching method

Sendust ribbons, about 20μm thick, 5.5∼6.5 mm wide and several meters long are made by a rapid quenching method. Ribbons obtained are so mechanically flexible that it is possible to wind them easily around a lod of 10 mm in diameter. The DC hysteresis loss changes with a flux density approximately as (B) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.8</sup> . The iron loss increases with frequency as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(f)^{1.4\sim1.5}</tex> and with flux density as (B) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.9</sup> . The eddy current loss increases with frequency as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(f)^{1.5\sim1.6}</tex> and with flux density as <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">(B)^{1.9\sim2.0}</tex> . The iron loss is lower than 19 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sup> W/m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> in the composition range around 9.5% Si and 5.6∼6.2% Al at the frequency of 100 kHz and at the flux density of 400 mT.

100 KHz-10 MHz iron loss measuring system

A very high frequency iron loss measuring system, the upper limit of frequency of which is 10MHz, is newly developed. This new system is helpful for elucidation of the mechanism generating power losses in magnetic cores used for MHz switching power supplies.

A high frequency iron loss measuring system

A high performance iron loss measuring system is introduced by using an 8-bit microcomputer, a two-channel memory device with high speed A/D converters and a wide band power amplifier. A required time to obtain a datum of one experimental point is about one minute when the error between the desired maximum flux density and the settled one is allowed within 0.5%. This system makes it possible to measure iron losses in the frequency range up to 1MHz. The results have a good correlation to the measured results by using the U-Function Meter.