Inductor

About: Inductor is a research topic. Over the lifetime, 52565 publications have been published within this topic receiving 484068 citations. The topic is also known as: passive two terminal.

Revised Magnetics Performance Factors and Experimental Comparison of High-Flux Materials for High-Current DC–DC Inductors

Abstract: High-flux-density materials, such as iron-based amorphous metal and 6.5% silicon steel for gapped inductors, and powdered alloys for gapless inductors, are very competitive for high-power-density inductors. The high-flux-density materials lead to low weight/volume solutions for high-power dc-dc converters used in hybrid-electric and electric vehicles. In this paper, the analytical selection of the magnetic materials is investigated, and modified performance factors are introduced for convection- and conduction-cooled magnetic components. The practical effects of frequency, dc bias, flux-density derating, duty cycle, airgap fringing on the core loss, and thermal configuration based on lamination direction are investigated for iron-based amorphous metal, 6.5% silicon steel, and iron-based powdered alloy material. A 2.5-kW converter is built to verify the optimum material selection and thermal configuration. Analytical, simulation, and experimental results are presented.

Integrated Coil Design for EV Wireless Charging Systems Using LCC Compensation Topology

Abstract: The double-sided LCC topology provides a highly efficient compensation method for electric vehicle (EV) wireless charging systems. However, the two compensated coils occupy a large volume. In order to address the volume increase as well as to be compatible with unipolar coil structures, which are widely applied in EV wireless charging systems, an integration method is introduced in this paper. Aspect ratios of the compensated coils are studied to minimize the respective coupling effect. With the proposed integration method, the extra coupling coefficients are either eliminated or decreased to a negligible level. A wireless charging system with the proposed integration method is built and the experimental results show that the system resonates at 85 kHz and delivers 3.09 kW with a dc–dc efficiency of 95.49% at an air gap of 150 mm. Furthermore, a comparison with the integration method into bipolar coil structures is presented and the results demonstrate that the system with the proposed integration method is more immune to front-to-rear and vertical misalignments.

A 25–75-MHz RF MEMS Tunable Filter

Abstract: This paper presents a state-of-the-art discrete RF microelectromechanical systems (MEMS) tunable filter designed for 25-75-MHz operation. This paper also presents an enhanced model of the RF MEMS switch, which is used for accurate prediction of the tunable filter response. The two-pole lumped-element filter is based on digital capacitor banks with on-chip metal-contact RF MEMS switches and lumped inductors, and results in a tuning range of 3:1 with fine frequency resolution, and a return loss better than 13 dB for the entire tuning range. The relative bandwidth of the filter is 4 plusmn 1% over the tuning range and the insertion loss is 3-5 dB, limited mostly by the inductor Q and the switch loss. The IIP3 measurements prove that tunable filters with metal-contact series RF MEMS switches show extremely linear behavior (IIP3 > 68 dBm).

New type LCCT-Z-source inverters

Abstract: Z-source inverters are suited for applications which require a large range of gain, such as in renewable energy. Recently proposed Trans-Z-source inverters (TZSIs) and T-source inverters (TSIs) characterize improved voltage gain thanks to the application of coupled inductors with turns ratio higher than one. The present paper extends the concept of Trans-Z-source (T-source) inverters. Two novel impedance networks: the LCCT (inductor-capacitor-capacitor-transformer) Z-source impedance network and the LCCT-qZ-source impedance network are presented. The former contains two built-in DC-current-blocking capacitors connected in series with transformer windings and therefore prevent the transformer core from saturation while the latter contains one built-in DC-current-blocking capacitor and combines the features of qZ-source and T-source impedance networks. The novel topologies of LCCT-impedance-source inverters: LCCT-Z-source inverter (LCCT-ZSI) and LCCT-quasi-Z-source inverter (LCCT-qZSI) proposed in the paper characterize available continuous input current which is the advantage compared to TZSIs and TSIs. Simulations and experimental results are provided to verify the analysis of two proposed topologies.

Reduction of high-frequency conduction losses using a planar litz structure

Abstract: A new trend in power converters is to design planar magnetic components that aim for low profile. However, at high frequencies, ac losses induced in the planar inductor and transformer windings become significant due to the skin and proximity effects. A planar litz conductor can be constructed by dividing the wide planar conductor lengthwise into multiple strands and weaving these strands in much the same manner as one would use to construct a conventional round litz wire conductor. Each strand is then equally subjected to the magnetic fields in the winding window, thereby equalizing the flux linkage and improving the current distribution. Three-dimensional finite-element modeling was performed for simple models. The simulation results showed that the planar litz conductor can result in lower ac resistance than a solid conductor over a specific frequency range. The performance of the planar litz winding was also verified with measurements on two experimental prototypes.