• Title/Summary/Keyword: DC characteristics

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A 3-Bridge LLC Resonant Converter with Wide Input/Output Voltage Gain Characteristics (넓은 입·출력 전압이득 특성을 갖는 3 브리지 LLC 공진컨버터)

  • Yoo, Sang-Jae;Jang, Ki-Chan;Kim, Eun-Soo;Jeon, Yong-Seog;Kook, Yoon-Sang
    • The Transactions of the Korean Institute of Power Electronics
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    • v.25 no.2
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    • pp.142-151
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    • 2020
  • This paper presents a DC/DC LLC resonant converter with wide input/output voltage gain characteristics and its control method for efficiency improvement. For a wide input/output voltage gain characteristics without designing small transformer magnetization inductance, the proposed converter changes the topology into three modes of operation according to the main switch switching pattern. In each operating mode, variable LINK voltage modulation and frequency modulation were performed to control output voltage and improve operating efficiency. A prototype of a 5-kW DC/DC LLC resonant converter was built and tested to verify the validity and applicability of the proposed converter.

The Dielectric Characteristics of Turn-to-Turn Insulation for DC Reactor Type HTSFCL (DC reactor type 고온호전도 한류기의 턴간 절연 특성)

  • 백승명;정종만;이창화;류엔반둥;김상현
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.16 no.12S
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    • pp.1299-1304
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    • 2003
  • Fault current limiters (FCL) are extensively needed to suppress fault currents, especially for trunk power systems heavily connected to high voltage/large current transmission lines. Due to its ideal electrical behavior, high-temperature superconductor fault current limiter (HTSFCL) becomes one of the most important developing trends of limiters in power system. This paper describes the result of an investigation of the dielectric characteristics of turn-to-turn insulation for pancake and solenoid type reactor coil in liquid nitrogen. The influence of thickness in a variety length, on AC, DC and impulse surface flashover has been investigated. Also, the relationships between the number of turn and breakdown characteristics were clarified. The information gathered in this test series should be helpful in the design of liquid nitrogen filled DC reactor type HTSFCL.

Prediction of Dynamic Characteristics of Small DC Motor (소형 직류 모터의 동특성 예측)

  • Kim, Kug-Weon;Ahn, Tae-Kil
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.2
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    • pp.107-112
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    • 2006
  • In this paper, described is a research on the modal analysis of small DC motor by finite element method fer the vibration reduction. An impact test is performed to obtain the natural frequencies and modal shapes of DC motor, which valuate the usefulness of the finite element analysis model. From the study, we show that this finite element analysis model can be applicable for designing a new motor with improvement in vibration characteristics. As an example, a shape modification of DC motor is performed and its vibration characteristics is discussed in comparison with those of original shape.

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Voltage-Resonant Type DC-DC Converter Using A-SCR (A-SCR을 사용한 전압 공진형 DC-DC 콘버어터)

  • Jung, Won-Young;Hwang, Don-Ha;Bae, Ki-Hoon;Ro, Chae-Cyun;Bae, Jin-Ho
    • Proceedings of the KIEE Conference
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    • 1992.07b
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    • pp.1029-1031
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    • 1992
  • This paper discussed the operational principles and characteristics of Voltage-Resonant Type DC-DC Converter of HF-Bridge Inverter Switching Control using A-SCR as switching elements. The characteristics of DC/DC Converter circuits were analyzed using the diagrams of design circuits and dimensionless control variables.

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A Characteristic Analysis of ZVS-Half Bridge type DC-DC Converter with the Capacity Variation of Source division Capacitor (전원분할 커패시터 용량변화에 따른 ZVS-HB형 DC-DC 컨버터의 특성 해석)

  • 오경섭;남승식;김동희
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.15 no.2
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    • pp.31-37
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    • 2001
  • This paper propose ZVS-HB type resonant DC/DC converter have earth different output characteristics using division ratio, not only a source division function but a resonant function and soft switching technique(ZVS, ZCS) instead of conventional source division capacitor. Circuit analysis generally described using normalized parameters most of characteristics with division ratio of source division capacitor. Also, this paper citified a rightfulness of characteristic analysis in comparison with a theoretical values and a experimental values obtain from experiment using Power-MOSFET.

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Analysis of Emission Characteristics of DC/DC Converter by Component Placement (부품배치에 따른 DC/DC 컨버터의 Emission 특성분석)

  • Park, Jin-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.639-643
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    • 2018
  • As electronic systems become smaller and more portable, the need for power conversion continues to increase. In addition, system stability must be ensured from switching noise due to power conversion efficiency and power conversion system miniaturization. Therefore, countermeasures to reduce switching noise during power conversion are essential. In this paper, a DC/DC buck converter circuit is constructed, and the characteristics of switching noise generated when changing the parts layout in a four-layer printed circuit board (PCB) structure with a reference plane are compared and analyzed. In addition, switching noise characteristics were compared and analyzed through simulations when the parts layout was different in a two-layer PCB structure from which the reference planes were removed. As a result, it was confirmed that the radiated emissions characteristic is reduced by 12dB and the conducted emissions characteristic decreased by 7dB to 8dB, according to the current return path in the four-layer PCB structure. Thus, it was confirmed that the noise characteristics can be improved according to the configuration of the current return path when the power conversion circuit is designed.

DC Traction Regenerative Energy Storage Devices using Super-capacitor (슈퍼 커패시터를 이용한 직류철도 회생에너지 저장장치)

  • Kim, Jong-Yoon;Jung, Doo-Yong;Jang, Su-Jin;Lee, Byoung-Kuk;Won, Chung-Yuen
    • The Transactions of the Korean Institute of Power Electronics
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    • v.13 no.4
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    • pp.247-256
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    • 2008
  • Regenerative energy generated by regenerative braking of DC traction can cause the system malfunction or damage to the rectifier, or malfunction of the power conversion device in power supply system by DC Line voltage rise in feeder line. Regenerative energy storage system using super capacitor is one of the ways to stabilize DC line voltage. In this paper, energy storage system of DC traction system using super-capacitor bank is implemented and using the field measurement data of the station N and the station S on the Line 2, the operation characteristics of line voltage caused by regenerative energy of electric trains are verified. Also, charge/discharge characteristics of super capacitor are verified as well. Thus, we can verify the operation characteristics of super-capacitor bank for regenerative energy storage system installed in DC Traction. And if we can use field measurement data of DC line voltage, we have obtained cost reduction. The stabilization of the system will be improved by measuring the operation characteristics of regenerative energy storage system in certain section operated by DC traction and predicting the capacity and lifetime of super-capacitor.

A Study on the Characteristics Analysis of LLC AC to DC High Frequency Resonant Converter capable of ZVZCS (ZVZCS가 가능한 LLC AC to DC 고주파 공진 컨버터의 특성 해석에 관한 연구)

  • Kim, Jong-Hae
    • Journal of IKEEE
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    • v.25 no.4
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    • pp.741-749
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    • 2021
  • This paper presents the current-fed type LLC AC to DC high frequency resonant converter capable of ZVZCS(Zero-Voltage and Zero-Current Switching). The current-fed type LLC AC to DC high frequency resonant converter proposed in this paper could operate not only in ZVS(Zero-Voltage Switching) operation by connecting the resonant capacitors(C1, C2) in parallel across the switching devices but also in ZCS(Zero-Current Switching) operation of the secondary diode. The ZVS and ZCS operations can reduce the turn-on loss of the switching devices and the turn-off loss of the secondary diodes, respectively. The circuit analysis of current-fed type LLC AC to DC high frequency resonant converter proposed in this paper is addressed generally by adopting the normalized parameters. The operating characteristics of proposed LLC AC to DC high frequency resonant converter were also evaluated by using the normalized control parameters such as the normalized control frequency(μ), the normalized load resistor(λ) and so on. Based on the characteristic values through the characteristics of evaluation, an example of the design method of proposed LLC AC to DC high frequency resonant converter is suggested, and the validity of the theoretical analysis is confirmed using the experimental results and PSIM simulation.

A Novel Boost DC-DC Converter using High Frequency Coupled Inductor Series Resonant ZCS-PFM Chopper Control Method (고주파 결합 인덕터 직렬 공진형 ZCS-PFM 초퍼 제어 방식을 이용한 새로운 승압형 DC-DC 컨버터)

  • Kim, Hong-Shin;Heo, Young-Hwan;Mun, Sang-Pil;Park, Han-Seok
    • The Transactions of the Korean Institute of Electrical Engineers P
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    • v.66 no.2
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    • pp.63-68
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    • 2017
  • This paper proposes a new non-isolated DC conversion circuit topology of the voltage source coupled inductor series resonant high-frequency PFM controlled boost chopper type DC-DC power converter using two in one IGBT power module, which can efficiently operate under a principle of zero current soft switching for wide output regulation voltage setting ranges and wide fluctuation of the input DC side voltage as well as the load variation ranges. Its steady state operating principle and the output voltage regulation characteristics in the open-loop-based output voltage control scheme without PI controller loop are described and evaluated from theoretical and experimented viewpoints. Finally, in this paper the computer-aided simulation steady-state analysis and the experimental results are presented in order to prove the effectiveness and the validity of voltage regulation characteristics of the proposed series resonant zero current soft switching boost chopper type DC-DC power converter circuit using IGBTs which is based on simple pulse frequency modulation strategy more than, 20kHz.

Design of wide Band Microwave Amplifier with Good Frequncy Characteristics (주파수 특성이 좋은 광대역 마이크로웨이브 증폭기의 설계)

  • Kang, Hee-Chang;park, Il;Chin, Youn-kang
    • The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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    • v.2 no.2
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    • pp.3-10
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    • 1991
  • The new structure method of GaAs microwave amplifiers using DC block function and impedance transforming property of DC block/transformer(non-symmetrical two - microstrip coupled line and interdigital three - microstrip coupled line), instead of chip capacitor, is presented. The newly structured microwave amplifier showed wideband characteristics(bandwidth, 3.5 GHz) and flat frequency response. Interdigital three - microstrip coupled line which is used for microwave amplifier can be used to match amplifiers as well as DC blocking.

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