Magnetic Components For Power Electronics Research Articles

Voltage Controlled Magnetic Components for Power Electronics

Voltage Controlled Magnetic Components for Power Electronics

カーボンニュートラルへ向けたパワーエレクトロニクス技術動向と磁気部品の応用技術

Recently, achieving carbon neutrality which means balancing CO2 emissions and absorption is a global concern. To realize carbon neutrality, developing power electronics technologies that significantly contribute to reducing the emission of CO2 are important issues. In addition, to smoothly develop next-generation power electronics technologies, interdisciplinary action and mutual understanding from the material, components, circuit, and system levels are important. Furthermore, magnetic components used in power converters are one of the basic and important components for improving power density and efficiency. Therefore, this paper presents the latest trend of power electronics technologies and applied technology of magnetic components for power electronics.

Thermal Resistance Matrix Extraction from Finite-Element Analysis for High-Frequency Magnetic Components

The thermal management of magnetic components for power electronics is crucial to ensure their reliability. However, conventional thermal models for magnetic components are known to have either poor accuracy or excessive complexity. Contrary to these models, the use of Thermal Resistance Matrices is proposed in this paper instead, which combine both accuracy and simplicity. They are usually used to characterize semiconductor devices, but not for magnetic components. The guidelines to apply Thermal Resistance Matrices for magnetic components are discussed in detail. The accuracy of this model is validated by 3D FEA simulations and experimental results, showing an absolute error lower than 5 ∘C and a relative error between −6.4% and 3.9%, which is outstanding compared to the carried-out literature review.

Ferrite Paste Cured With Ultraviolet Light for Additive Manufacturing of Magnetic Components for Power Electronics

Additive manufacturing (AM) has the potential to rapidly prototype innovative designs of magnetic components aimed at improving power density and efficiency of switch-mode power converters. However, only a few magnetic feedstocks are available for AM, and the fabricated parts have significantly poorer magnetic properties. Our previous studies showed the promise of an extrusion-based AM platform for making high-performance power magnetics. But, the magnetic paste feedstock developed in these studies suffered from the “slumping” problem, thus not suitable for building large or tall core structures. To improve the AM capability, a ferrite paste was developed that is cured upon ultraviolet (UV) illumination. Core structures with large aspect ratios were fabricated by retrofitting the printer with a UV-light-emitting diode module. By varying the magnetic composition of the paste and sintering the printed parts at and below 1000 °C, we made tall (>4 mm) ferrite cores with relative permeability ranging from 63 to 103 and resonance frequency higher than 30 MHz.

Numerical modelling of PCB planar inductors: impact of 3D modelling on high‐frequency copper loss evaluation

Loss values are key parameters for designing high-performance high-frequency magnetic components for power electronics (PE) converters. With the increase of PE switching frequencies, copper losses have to be precisely quantified, ideally until some megahertz. In the literature, many 2D numerical simulations based on finite element analysis (FEA) are performed for such computations. 3D FEA studies of planar components are still limited because of modelling problems, computational resources and computing time. In this study, quantitative comparisons between 2D and 3D simulation results for planar inductors are achieved focusing on copper loss computation. Results are compared in terms of simulation performances and accuracy. The aim of the study is to highlight benefits of 2D and 3D FEA simulations in order to choose the appropriate model according to the studied problem.

Study of magnetic properties of NiZnCu ferrite synthesized by Pechini method and solid-state reactions

Ni-Zn-Cu ferrites are exhibiting excellent magnetic properties at large frequencies and are consequently produced as low-loss magnetic materials used for magnetic components in power electronics. Here we present an experimental study of (Ni0.31Zn0.49Cu0.20)0.979Co0.021Fe1.9-dO4 ferrites synthesized by the Pechini type sol-gel method. Their structural and magnetic properties are characterized and compared to the ones of reference ferrites synthesized by classical solid-state reactions. Optimized parameters for Pechini method allow obtaining comparable low magnetic core-losses for both synthesis methods. The cores obtained by this sol-gel method present higher static permeability and lower coercive field than the ones obtained by classical solid-state reactions. Results suggest that the microstructure of ferrites synthesized by Pechini method can be considered as a promising alternative route for the design of low-loss magnetic components.

Model-order reduction of magneto-harmonic problems based on POD: application to planar magnetic components

Predetermination of losses and inductance values in the design phase, is necessary for the development of high-performance magnetic components for power electronics. Numerical modeling, based on the finite element method (FEM) can be used to determine the characteristics of a particular component with a complex geometry in high frequency (HF). These models are very accurate but the computation time required is high compared to analytical models. The model order reduction (MOR) methods can be applied to reduce the computation time while maintaining high accuracy. Nowadays, the proper orthogonal decomposition (POD) is the most popular of MOR approaches. This technique has been applied to study problems in many fields of engineering. In this paper, the POD method is developed to solve magneto-harmonic problems in order to study a HF planar magnetic inductor.

Improved Thermal Modelling of Magnetic Components for Power Electronics

An improved thermal modelling of convection and radiation heat transfer for magnetic components for power electronics is presented. The proposed model of convection heat transfer uses more precise values of the exponents in the presentation of the convection coefficient hc as well as a reduced surface of the component. The model for radiation includes precise values of the emissivity of the component surface and also a reduced ‘envelope’ surface. Accurate thermal measurements of two experimental models (box shape and transformer shape, size EE42) were done for four different kinds of surfaces of the models to derive and verify the proposed models. The improved models can be used in an accurate thermal design of magnetic components.

Magnetic properties and domain structures in stress-annealed FeZrB-(Cu)-(Nb) nanocrystalline ribbons

Magnetic properties of nanocrystalline FeZrB-(Cu)-(Nb) compared to FeSiBCuNb are reported. Observations of domain patterns by magneto-optical Kerr effect (MOKE) method presented herein highlight qualitatively the incidence of stress-annealing on the induced anisotropy in soft magnetic materials. Transverse fine domains found in FeSiBCuNb alloys are consistent to a magneto-elastic interpretation of the stress-induced anisotropy. Nevertheless, it is not the case for FeZrB-(Cu)-(Nb) family where we observe a pronounced longitudinal induced anisotropy. According to the so-called “back stress effect” advanced by Herzer, the negative of bcc α-Fe grains, as well of bcc α-FeSi grains, should yield transverse anisotropy. Nowadays, this surprising feature is not still clear. For a technical standpoint, stress-induced anisotropy is interesting for new magnetic components in power electronics.

Applications of amorphous magnetic alloys in electronic devices

Some of the features of amorphous magnetic alloys that differentiate them from other soft magnetic materials include: low magnetic loss, fast flux reversal, high electrical resistivity and low acoustic loss. Furthermore, a wide range of B– H characteristics can be obtained through alloy design and heat-treatment of the alloys under different conditions. The versatile properties thus obtained can then be utilized in a number of magnetic applications ranging from large electrical power devices such as transformers and motors to recording heads and to anti-pilferage markers. This paper reviews the applications of various amorphous magnetic alloys in electronic devices including magnetic components in power electronics, telecommunication equipment, automotive parts and sensing devices. Relationships between property requirements and material capabilities are also discussed.

Issues and advances in high-frequency magnetics for switching power supplies

Magnetic components have been and will continue to be an essential element in power conversion and management circuits. Due to this pivotal role, magnetic components have seen continuous efforts to develop materials, winding structures, and manufacturing and assembly techniques toward the never ending goals of high efficiency, smaller size, and automated manufacturing. The authors present an up-to-date view as well as an outlook for the future covering the technologies that have enabled the advanced in magnetic components for power electronics in telecommunications. Finally, they also provide their view on emerging technologies in this field in line with broader developments in the telecommunications, electronics and semiconductor industries.