• Title/Summary/Keyword: High Power density

Search Result 2,172, Processing Time 0.031 seconds

Half-Bridge Series Resonant Converter Using A LLCT for High Density Switching Power Supply (LLCT적용 고집적 스위칭 전원을 위한 Half-Bridge 직렬 공진컨버터)

  • Park, J.Y.;Kong, Y.S.;Hwang, I.G.;Kim, E.S.
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.11 no.1
    • /
    • pp.56-64
    • /
    • 2006
  • Recently, high density power supply has been researched over the last few years. To achieve high density power supply, the series resonant converter has been steadily used. In this paper, the half-bridge series resonant converter using the integrated Inductor-Inductor-Capacitor-Transformer(LLCT) is described. The structure of LLCT is analysed by the use of Finite Element Method Magnetics(FEMM) Software. Also the experimental results are verified by the simulation based on the theoretical analysis and the 300W experimental prototype.

A Design of Linear Motor with High Power Density and High Efficiency for Railway and Magnetic Levitation System (철도 차량용 고출력 고효율 선형 추진시스템 설계)

  • Kang, D.H.
    • Proceedings of the KIEE Conference
    • /
    • 2001.04a
    • /
    • pp.393-396
    • /
    • 2001
  • According to the development of power electronic element(GTO, IGBT) and material for electrical machines(permanent magnet, super conductor), the technology for electrical machines is nowaday rapidly developing. Here with, a novel electrical machine, based on the new conception of transverse flux configuration leads to a considerable Increase in power density and enables simultaneously high efficiency. The transverse flux machine with PM excitation will be applied to gearless direct drives for railway traction system and magnetic levitation system. The designed and measured performance of transverse machine for railway traction system and magnetic levitation system revealed a great potential of system improvements to reduce linear motor mass and increase efficiency.

  • PDF

Two Phase Interleaved LLC Resonant Converter (Two Phase Interleaved LLC 공진 컨버터)

  • Kim, Joo-Hoon;Lee, Kwang-Ho;Kim, Eun-Soo;Lee, Jae-Sam;Lee, Hyun-Kwan;Jung, Yong-Chae
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.14 no.5
    • /
    • pp.397-405
    • /
    • 2009
  • Nowadays, power supplies for LCD TV of larger and slimmer screen size are required to have high power density and high efficient characteristics. In order to meet these requirements, Multi-phase interleaved LLC resonant converter is applied for increasing power density and reducing the current rating in the used devices. In this paper, gain characteristics and the experimental results of the proposed two-phase LLC resonant converter which implemented by the simple control circuit are verified based on the theoretical analysis and the 300W experimental prototype.

High Power-Density LDC Design for Ultra-Compact Electric Vehicles (초소형 전기자동차용 고밀도 LDC 설계)

  • Kim, Tae-Won;Lee, Jae-Won;Kim, Jun-Min;Kim, Gu-Yong;Kim, Jun-Ho
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.26 no.3
    • /
    • pp.199-204
    • /
    • 2021
  • Ultra-compact electric vehicles have narrow space for power conversion devices. This work presents schemes to achieve the high-power density of a low-voltage DC-DC converter (LDC): simplifying a converter structure by using sync-buck topology, applying a planar inductor using PCB winding, and applying a plate-type heat sink. The heat sink is placed between two PCBs, which increases the contact surface between the PCB and the heat-dissipating device. It enables the miniaturization of the converter to improve the conditions of heat radiation. The validity of the proposed scheme is verified through the experiment using a 500 W(12 V, 41.67 A) prototype with an input voltage range from 58 V to 84 V.

Pulse-Grouping Control Method for High power Density DC/DC Converters

  • Kang, Shin-Ho;Jang, Jun-Ho;Lee, Jun-Young
    • Journal of the Semiconductor & Display Technology
    • /
    • v.6 no.2 s.19
    • /
    • pp.45-48
    • /
    • 2007
  • The proposed method offers an improved DC/DC converter scheme to increase power density. It is based on half-bridge topology with newly introduced pulse-grouping control method, which helps to reduce the transformer size and the volume of semiconductor devices maintaining high efficiency. Test results with 85W(18.5V/4.6A) design shows that the measured efficiency is 93.5% with power density of $36W/in^3$.

  • PDF

100W On-Board Power Supply Using Flat Transformer (Flat Transformer를 이용한 100W급 On-Board Power Supply)

  • 황치면;송두익;조정구;정창용;홍승대;하태복
    • Proceedings of the KIPE Conference
    • /
    • 1999.07a
    • /
    • pp.577-580
    • /
    • 1999
  • High power density on-board power supply is implemented by using flat transformer. In the high frequency switching converters, large leakage inductance increases the switching stress and duty cycle loss, which sometimes limits maximum switching frequency. The flat transformer is designed by using special core structure, which has very low profile and low temperature rise since the thermal loading is spread evenly over a larger area. 100W, 3.3V output on board supply is built and tested and 50.7W/$\textrm{inch}^{3}$ power density is achieved.

  • PDF

Effect of Laser Surface Hardening Factors on the Wear Resistance of Medium Carbon Low Alloy Steel Surface-hardened by Using CO2 Laser Technique (CO2 레이저 표면경화처리된 중탄소 저합금강의 내마모 특성에 미치는 레이저 표면경화 인자의 영향)

  • Park, K.U.;Roh, Y.S.;Han, Y.H.;Lee, S.Y.
    • Journal of the Korean Society for Heat Treatment
    • /
    • v.5 no.2
    • /
    • pp.122-132
    • /
    • 1992
  • This study has been performed to investigate into some effects of the power density and traverse speed of laser beam on the optical microstructure, hardness and wear characteristics of medium carbon low alloy steel treated by laser surface hardening technique. The results obtained from the experiment are summarized as follows : (1) Optical micrograph has shown that finer lath martensite is formed and the amount of undissolved complex carbides increases as the traverse speed increases under the condition of a given power density, whereas the coarsening of lath martensite and the reduction of undissolved complex carbides occur with increasing the power density at a given traverse speed. (2) Hardness measurements have revealed that as the traverse speed increases, hardness values of outermost surface layer more of less decrease under low power densities, but are uniformly distributed under high power densities, also showing that they are uniformly distributed at low traverse speeds and more or less decrease at high traverse speeds with increasing the power density. (3) The effective case depth has been found to decrease from 0.26 mm to 0.17 mm with increasing the traverse speed from 1.5 m/min to 3.0 m/min at a given power density of $25.48{\times}10^3w/cm^2$ and to increase from 0.20 mm to 0.36 mm with increasing the power density from $19.11{\times}10^3w/cm^2$ to $38.22{\times}10^3w/cm^2$ at a given traverse speed of 2.0 m/min. (4) Wear test has exhibited that the amount of weight loss of laser surface hardened specimen with respect to sliding distance at a given load increases with increasing traverse speed at a given power density and decreses with increasing power density at a given traverse speed.

  • PDF

A High Efficiency, High Power-Density GaN-based Triple-Output 48V Buck Converter Design (GaN MOSFET을 이용한 고밀도, 고효율 48V 버스용 3-출력 Buck Converter 설계)

  • Lee, Sangmin;Lee, Seung-Hwan
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.25 no.5
    • /
    • pp.412-419
    • /
    • 2020
  • In this study, a 70 W buck converter using GaN metal-oxide-semiconductor field-effect transistor (MOSFET) is developed. This converter exhibits over 97 % efficiency, high power density, and 48 V-to-12 V/1.2 V/1 V (triple output). Three gate drivers and six GaN MOSFETs are placed in a 1 ㎠ area to enhance power density and heat dissipation capacity. The theoretical switching and conduction losses of the GaN MOSFETs are calculated. Inductances, capacitances, and resistances for the output filters of the three buck converters are determined to achieve the desired current, voltage ripples, and efficiency. An equivalent circuit model for the thermal analysis of the proposed triple-output buck converter is presented. The junction temperatures of the GaN MOSFETs are estimated using the thermal model. Circuit operation and temperature analysis are evaluated using a circuit simulation tool and the finite element analysis results. An experimental test bed is built to evaluate the proposed design. The estimated switch and heat sink temperatures coincide well with the measured results. The designed buck converter has 130 W/in3 power density and 97.6 % efficiency.

The Design of PC-based Power Spectral Density Analyzer of Heart Rate Variability (PC-기반의 심박변동 팍워스픽트럼밀도 분석기 설계)

  • 김낙환;이응혁;민홍기;홍승홍
    • The Transactions of the Korean Institute of Electrical Engineers D
    • /
    • v.52 no.9
    • /
    • pp.547-553
    • /
    • 2003
  • In this paper, we designed the PC-based analyzer of the power spectral density that could estimate the heart rate variability from time series data of R-R interval. The power spectral density estimated that it applied the autoregressive model to the measured electrocardiogram during a short period. Also, the characteristics of the designed analyzer are that it could process of the signal filtering, the generation and recomposition of time series and the feature extraction at the same time. Especially the analyzer reconstructed which applied the lowpass filter of the time series composed by the linear interpolation so as to enhance the signal-to-noise feature. We could estimate the power spectral density that confirmed a variety of power peak with low frequency range and high frequency rang of autonomic nerve by the heart rate variability.

Density distributions and Power spectra of outflow-driven turbulence

  • Kim, Jongsoo;Moraghan, Anthony
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.39 no.1
    • /
    • pp.57.2-57.2
    • /
    • 2014
  • Protostellar jets and outflows are signatures of star formation and promising mechanisms for driving supersonic turbulence in molecular clouds. We quantify outflow-driven turbulence through three-dimensional numerical simulations using an isothermal version of the total variation diminishing code. We drive turbulence in real space using a simplified spherical outflow model, analyze the data through density probability distribution functions (PDFs), and investigate density and velocity power spectra. The real-space turbulence-driving method produces a negatively skewed density PDF possessing an enhanced tail on the low-density side. It deviates from the log-normal distributions typically obtained from Fourier-space turbulence driving at low densities, but can provide a good fit at high densities, particularly in terms of mass-weighted rather than volume-weighted density PDF. We find shallow density power-spectra of -1.2. It is attributed to spherical shocks of outflows themselves or shocks formed by the interaction of outflows. The total velocity power-spectrum is found to be -2.0, representative of the shock dominated Burger's turbulence model. Our density weighted velocity power spectrum is measured as -1.6, slightly less that the Kolmogorov scaling values found in previous works.

  • PDF