• Title, Summary, Keyword: DC-DC power conversion

Search Result 615, Processing Time 0.037 seconds

Single-Power-Conversion Series-Resonant AC-DC Converter with High Efficiency (고효율을 갖는 단일 전력변환 직렬 공진형 AC-DC 컨버터)

  • Jeong, Seo-Gwang;Cha, Woo-Jun;Lee, Sung-Ho;Kwon, Bong-Hwan
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.21 no.3
    • /
    • pp.224-230
    • /
    • 2016
  • In this study, a single-power-conversion series-resonant ac-dc converter with high efficiency and high power factor is proposed. The proposed ac-dc converter consists of single-ended primary-inductor converter with an active-clamp circuit and a voltage doubler with series-resonant circuit. The active-clamp circuit clamps the surge voltage and provides zero-voltage switching of the main switch. The series-resonant circuit consists of leakage inductance $L_{lk}$ of the transformer and resonant capacitors $ C_{r1}$ and $ C_{r2}$. This circuit also provides zero-current switching of output diodes $D_1$ and $D_2$. Thus, the switching loss of switches and reverse-recovery loss of output diodes are considerably reduced. The proposed ac-dc converter also achieves high power factor using the proposed control algorithm without the addition of a power factor correction circuit and a dc-link electrolytic capacitor. A detailed theoretical analysis and the experimental results for a 1kW prototype are discussed.

A new proposal of three-step dc-dc converter scheme for solar power system

  • Lee, Hee-Chang;Park, Sung-Joon
    • Journal of information and communication convergence engineering
    • /
    • v.5 no.4
    • /
    • pp.358-361
    • /
    • 2007
  • We report on a new type dc-dc converter design that combines the advantage of dc ripple noise elimination and high efficiency. As potential low cost solar cells, DSC module and the panel's system efficiency and stability are still critical problems to the way of marketing. In this study, a new three-step dc-dc converter scheme with the phase-shift-carrier technology is proposed to apply for solar power system. We have achieved power conversion efficiency around 94.88%.

Load-Balance-Independent High Efficiency Single-Inductor Multiple-Output (SIMO) DC-DC Converters

  • Ko, Younghun;Jang, Yeongshin;Han, Sok-Kyun;Lee, Sang-Gug
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.14 no.3
    • /
    • pp.300-312
    • /
    • 2014
  • A single-inductor multiple-output (SIMO) DC-DC converter providing buck and boost outputs with a new switching sequence is presented. In the proposed switching sequence, which does not require any additional blocks, input energy is delivered to outputs continuously by flowing current through the inductor, which leads to high conversion efficiency regardless of the balance between the buck and boost output loads. Furthermore, instead of multiple output loop compensation, only the freewheeling current feedback loop is compensated, which minimizes the number of off-chip components and nullifies the need for the equivalent series resistance (ESR) of the output capacitor for loop compensation. Therefore, power conversion efficiency and output voltage ripples can be improved and minimized, respectively. Implemented in a 0.35-${\mu}m$ CMOS, the proposed SIMO DC-DC converter achieves high conversion efficiency regardless of the load balance between the two outputs with maximum efficiency reaching up to 82% under heavy loads.

Power Conversion System for Electric Power Take-off of Agricultural Electric Vehicle (농업용 전기차량의 전기식 동력인출장치용 전력변환시스템)

  • Kwak, Bongwoo;Kim, Jonghoon
    • Journal of IKEEE
    • /
    • v.23 no.3
    • /
    • pp.994-1002
    • /
    • 2019
  • In this paper, we propose the development of a power conversion system for electric power take-off (e-PTO) of agricultural electric vehicles. Most e-PTOs use commercial power $220V_{AC}$. A bidirectional power conversion system having a two-stage structure consisting of a DC-DC converter and a DC-AC inverter for supplying a high output voltage using a low battery voltage of an agricultural electric vehicle is suitable. we propose a power conversion system consisting of the one-stage dual active bridge (DAB) converter and the two-stage bidirectional full bridge inverter. In addition, we propose a soft start algorithm for reducing the inrush current generated by the link capacitor charging during the initial operation. A 3kW prototype system and its corresponding algorithms have been implemented to verify its effectiveness through experiments.

Implementation and Problem Analysis of Phase Shifted dc-dc Full Bridge Converter with GaN HEMT (Cascode GaN HEMT를 적용한 위상 천이 dc-dc 컨버터의 구현 및 문제점 분석)

  • Joo, Dong-Myoung;Kim, Dong-Sik;Lee, Byoung-Kuk;Kim, Jong-Soo
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.20 no.6
    • /
    • pp.558-565
    • /
    • 2015
  • Gallium nitride high-electron mobility transistor (GaN HEMT) is the strongest candidate for replacing Si MOSFET. Comparing the figure of merit (FOM) of GaN with the state-of-the-art super junction Si MOSFET, the FOM is much better because of the wide band gap characteristics and the heterojunction structure. Although GaN HEMT has many benefits for the power conversion system, the performance of the power conversion system with the GaN HEMT is sensitive because of its low threshold voltage ($V_{th}$) and even lower parasitic capacitance. This study examines the characteristics of a phase-shifted full-bridge dc-dc converter with cascode GaN HEMT. The problem of unoptimized dead time is analyzed on the basis of the output capacitance of GaN HEMT. In addition, the printed circuit board (PCB) layout consideration is analyzed to reduce the negative effects of parasitic inductance. A comparison of the experimental results is provided to validate the dead time and PCB layout analysis for a phase-shifted full-bridge dc-dc converter with cascode GaN HEMT.

A Study on Bipolar DC-DC Converter for Low Voltage Direct Current Distribution (저압 직류 배전용 양극성 DC-DC 컨버터에 관한 연구)

  • Lee, Jung-Yong;Kim, Ho-Sung;Cho, Jin-Tae;Kim, Ju-Yong;Cho, Younghoon
    • The Transactions of the Korean Institute of Power Electronics
    • /
    • v.24 no.4
    • /
    • pp.229-236
    • /
    • 2019
  • This study proposes a DC-DC converter topology of solid-state transformer for low-voltage DC distribution. The proposed topology consists of a voltage balancer and bipolar DC-DC converter. The voltage and current equations are obtained on the basis of switching states to design the controller. The open-loop gain of the controller is achieved using the derived voltage and current equations. The controller gain is selected through the frequency analysis of the loop gain. The inductance and capacitance are calculated considering the voltage and current ripples. The prototype is fabricated in accordance with the designed system parameters. The proposed topology and designed controller are verified through simulation and experiment.

Improved DC-DC Bidirectional Converter (개선된 DC-DC 양방향 컨버터)

  • Kim, Seong-Hwan;Hur, Jae-Jung;Jeong, Bum-Dong;Yoon, Kyoung-Kuk
    • Journal of the Korean Society of Marine Engineering
    • /
    • v.41 no.1
    • /
    • pp.76-82
    • /
    • 2017
  • Since the introduction of electronically controlled engines and electric propulsion ships, the need for an uninterruptible power supply for emergency power supply devices that use batteries has gained importance. The bidirectional converter in such emergency power supply devices is a crucial component. This paper proposes, a topology for an improved DC-DC bidirectional converter that is characterized by a high voltage conversion ratio and low voltage stress of switches. To confirm the performance of the converter, a computer simulation was executed with PSIM software. The conversion ratio of the proposed converter was found to be four times higher than the conventional boost converter in step-up mode and one-fourth that of the conventional buck converter in step-down mode, and the voltage stress of the switches was one-fourth of the high-side voltage. Moreover, the proposed converter was confirmed to be able to distribute equal currents between two interleaved modules without using any extra current-sharing control method because of the charge balance of its blocking capacitors.

Rectifier Design Using Distributed Greinacher Voltage Multiplier for High Frequency Wireless Power Transmission

  • Park, Joonwoo;Kim, Youngsub;Yoon, Young Joong;So, Joonho;Shin, Jinwoo
    • Journal of electromagnetic engineering and science
    • /
    • v.14 no.1
    • /
    • pp.25-30
    • /
    • 2014
  • This paper discusses the design of a high frequency Greinacher voltage multiplier as rectifier; it has a greater conversion efficiency and higher output direct current (DC) voltage at high power compared to a simple halfwave rectifier. Multiple diodes in the Greinacher voltage multiplier with distributed circuits consume excited power to the rectifier equally, thereby increasing the overall power capacity of the rectifier system. The proposed rectifiers are a Greinacher voltage doubler and a Greinacher voltage quadrupler, which consist of only diodes and distributed circuits for high frequency applications. For each rectifier, the RF-to-DC conversion efficiency and output DC voltage for each input power and load resistance are analyzed for the maximum conversion efficiency. The input power with maximum conversion efficiency of the designed Greinacher voltage doubler and quadrupler is 3 and 7 dB higher, respectively;than that of the halfwave rectifier.

Digital Controller for DC-DC Converters (DC-DC 컨버터를 위한 디지털 방식의 컨트롤러 회로)

  • Hong, Wanki;Kim, Kitae;Kim, Insuck;Roh, Jeongjin
    • Journal of the Institute of Electronics Engineers of Korea SD
    • /
    • v.42 no.10
    • /
    • pp.39-46
    • /
    • 2005
  • A DC-DC converter with digital controller is realized. the digital controller has several advantages such as robustness, fast design time, and high flexibility. however, since the DC-DC output voltage is analog, an analog-to-digital conversion scheme is always essential in all digital controllers. A simple and efficient delta-sigma modulator is used as a conversion scheme in out implementation. The measurement results show good voltage regulation

Efficiency improvement of a DC/DC converter using LTCC substrate

  • Jung, Dong Yun;Jang, Hyun Gyu;Kim, Minki;Park, Junbo;Jun, Chi-Hoon;Park, Jong Moon;Ko, Sang Choon
    • ETRI Journal
    • /
    • v.41 no.6
    • /
    • pp.811-819
    • /
    • 2019
  • We propose a substrate with high thermal conductivity, manufactured by the low-temperature co-fired ceramic (LTCC) multilayer circuit process technology, as a new DC/DC converter platform for power electronics applications. We compare the reliability and power conversion efficiency of a converter using the LTCC substrate with the one using a conventional printed circuit board (PCB) substrate, to demonstrate the superior characteristics of the LTCC substrates. The power conversion efficiencies of the LTCC- and PCB-based synchronous buck converters are 95.5% and 94.5%, respectively, while those of nonsynchronous buck converters are 92.5% and 91.3%, respectively, at an output power of 100 W. To verify the reliability of the LTCC-based converter, two types of tests were conducted. Storage temperature tests were conducted at -20 ℃ and 85 ℃ for 100 h each. The variation in efficiency after the tests was less than 0.3%. A working temperature test was conducted for 60 min, and the temperature of the converter was saturated at 58.2 ℃ without a decrease in efficiency. These results demonstrate the applicability of LTCC as a substrate for power conversion systems.