Magnetic core

About: Magnetic core is a research topic. Over the lifetime, 30011 publications have been published within this topic receiving 155247 citations.

Fe-based soft magnetic alloy

Abstract: An Fe-based soft magnetic alloy essentially consisting of an Fe-based alloy including fine crystal grains used for such as a magnetic core. An average size of the fine crystal grains is controlled to 300 Å or less. Each of the fine crystal grains is composed of a body-centered cubic phase at least partially including a super lattice. This alloy has a high saturation flux density and excellent soft magnetic characteristics such as a low iron loss and a high magnetic permeability.

ELF magnetic field mitigation by active shielding

Abstract: The reduction of extremely low frequency (ELF) magnetic field in an area excited by power frequency currents is investigated by active shielding techniques. The magnetic field inside a shielded area is measured in simple test configurations. The performances of the proposed field-controlled active shield are showed.

Multipermeability Inductors for Increasing the Inductance and Improving the Efficiency of High-Frequency DC/DC Converters

Abstract: Distributed air-gap inductors such as iron powder chip inductors and low-temperature cofired ceramic (LTCC) inductors have the advantage of low-fringing effect loss However, the flux density nonuniformly distributes in the magnetic cores, which results in the magnetic material closer to the conductor becoming saturated while the magnetic material further away from the conductor is still not fully utilized This paper proposes a multipermeability distributed air-gap inductor structure to increase inductance without the necessity of increasing the inductor volume The best discrete permeability value is investigated Based on the best discrete permeability value, inductance as well as the inductance density trends is calculated by varying the number of permeability layers under the condition that thickness for each layer is constant Also, the inductance variations versus the number of permeability layers are also obtained under the condition that the inductor thickness is constant A three-permeability inductor and a single-permeability inductor are fabricated to evaluate the proposed method The measured results show that the three-permeability inductor has a much higher inductance than the single-permeability inductor for the entire load range Both inductors are tested in a 5-V input, 3-V output dc/dc converter to compare their performances The results show that the three-permeability inductor can further improve the efficiency of high-frequency dc/dc converters

Real-time monitoring of iron-core and copper losses of transformers Under(Non)Sinusoidal operation

Abstract: The online monitoring of iron-core and copper losses of single- and three-phase transformers is important, particularly for transformers feeding nonlinear loads. This paper devises a new digital data acquisition method for the separate online measurement of iron-core and copper losses of three-phase transformers under any full or partial-load conditions. The accuracy requirements of the instruments (voltage and current sensors, voltmeters, and ammeters) employed are addressed. The measurement uncertainties are acceptably low if voltage and current sensors with 0.1%-0.5% accuracy are used.

Study on Vibration of Iron Core of Transformer and Reactor Based on Maxwell Stress and Anisotropic Magnetostriction

Abstract: In this paper, the magnetostrictive orthogonal calculation method is used to simulate the vibration of iron cores of the transformer and shunt reactor models. The two models have the same size except there is a 2 mm air gap in the middle core of the reactor model. The Maxwell stress and total stress on the two cores are quantitatively calculated. The calculated results show that the air gap has a great influence on the vibration of the shunt reactor core. The Maxwell stress is the main reason for the vibration of the reactor core, but the vibration of the transformer core is mainly caused by magnetostriction. Finally, the experimental platform is built to measure the vibration accelerations of the two models and verify the results of the simulation.