Magnetic core

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

A Simple and Efficient Quasi-3D Magnetic Equivalent Circuit for Surface Axial Flux Permanent Magnet Synchronous Machines

Abstract: This paper presents a simple and efficient magnetic equivalent circuit (MEC) model for surface axial flux permanent magnet synchronous machines. The MEC model is used to solve all the electromagnetic properties of the machine including the no load, full load voltages, cogging torque, torque ripple, and stator iron core losses. Moreover, this approach can be extended for all surface permanent magnet synchronous machines. The main novelty of this approach is the development of a static system, which accounts for the rotation. The model takes into account the rotor rotation via time-dependent permanent magnet magnetization sources. The static system matrix facilitates a very fast solving. In addition, to take into account the three-dimensional (3-D) effect, a multislicing of the machine in the radial direction is done. This boosts the simulation time to only 60 s for six slices and 50 time steps including the nonlinear behavior of the stator elements with a great accuracy. Additionally, the number of elements in the MEC can be adjusted to reduce the computational time. This model is verified by means of 3-D and two-dimensional (2-D) multislice finite-element models. In addition, experimental validations are also provided at the end.

Ferromagnetic RF inductors and transformers for standard CMOS/BiCMOS

Abstract: Integrated solenoidal radio-frequency (RF) inductors and transformers with a ferromagnetic core are demonstrated by using a fully IC-compatible fabrication process. For a 500-nm-thick Ni/sub 80/Fe/sub 20/ film, a cut-off frequency of over 7.5 GHz for a 2.5-nH inductor is realized. Optimum inductor design based on tailored inductance, quality factor, and cut-off frequency is discussed. RF transformers realized have a coupling factor of /spl sim/70% up to 200 MHz.

Core Loss Calculation Based on Finite-Element Method With Jiles–Atherton Dynamic Hysteresis Model

Abstract: For accurate computation of core losses, the Jiles–Atherton ( $J$ – $A$ ) dynamic hysteresis model accounting for hysteresis, eddy current and excess losses is incorporated into the finite-element method (FEM). The $J$ – $A$ dynamic hysteresis model is constructed by combining the traditional $J$ – $A$ hysteresis model with the models of instantaneous eddy current and excess losses. The $J$ – $A$ model parameters and dynamic loss coefficients are determined by fitting the models to the measurement data of a single sheet tester (SST 500) and Epstein frame tester. To find the robust best fit, the particle swarm optimization algorithm is employed. By using the proposed $J$ – $A$ dynamic hysteresis model and FEM, the magnetic characteristics of a magnetic core is simulated and the core loss distribution within the core obtained. The calculated and measured results are compared to show the accuracy and effectiveness of the proposed model.

Load characteristics of a spiral coil type thin film microtransformer

Abstract: A spiral coil type thin film microtransformer with a size of 2.4*3.1 mm/sup 2/ is fabricated using photolithography techniques for application in megahertz region switching regulators. An amorphous magnetic film of a multilayered CoNbZr/SiO/sub 2/ is used as a magnetic core. Load characteristics are measured at 10 MHz. A comparatively high efficiency of 67% and an acceptable excitation current of 25 mA are obtained, in spite of the small size of the microtransformer. >

A Miniaturized Magnetic Field Sensor System Consisting Of A Planar Fluxgate Sensor And A Cmos Readout Circuitry

Abstract: We report on a miniaturized magnetic field sensor system consisting of a fluxgate sensor fabricated in CMOS-compatible planar technology and a CMOSASIC for sensor supply, readout and signal processing using second harmonic principle with a feedback loop for zero field operation. The system exhibits a sensitivity of 9.2k0.1 mV/pT for a magnetic field range of k 9 h T and a temperature range of 0°C to 70°C. The 3 dl3 bandwith is 300 Hz and a noise value of 30 n T m was estimated. Using 5V supply voltage a power consumption of 16OmW for the system was measured.