• Title/Summary/Keyword: Output Ripple Current

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Development of 1.2[kW]Class Fuel Cell Power Conversion System (1.2[kW]급 연료전지용 전력변환장치의 개발)

  • Suh, Ki-Young;Kim, Chil-Ryong;Cho, Man-Chul;Kim, Jung-Do;Yoon, Young-Byun;Kim, Hong-Sin;Park, Do-Hyung;Ha, Sung-Hyun
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.21 no.6
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    • pp.117-125
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    • 2007
  • Recently, a fuel cell with low voltage and high current output characteristics is remarkable for new generation system. It needs both a DC-DC step-up converter and DC-AC inverter to be used in fuel cell generation system. Therefor, this paper, consists of an isolated DC-DC converter to boost the fuel cell voltage 380[VDC] and a PWM inverter with LC filter to convent the DC voltage to single-phase 220[VAC]. Expressly, The fuel cell system which it proposes DC-DC the efficient converter used PWM the phase transient control law and it depended to portion resonance ZVS switching, loss peek voltage and electric current of realization under make schedule, switching frequency anger and the switch reduction. And mind benevolence it sprouted 2 in stop circuit and it added and a direct current voltage and the electric current where the ingredient is reduced in load side ripple stable under make whom it will be able to supply. Besides the efficiency of 92[%]is obtained over the wide output voltage regulation ranges and load variations. Also, under make over together the result leads simulation and test, the propriety confirmation.

Development of Novel 3-Phase Line-interactive UPS System using 4-leg PWM Converter/Inverter and AC Reactor (4-레그 PWM 컨버터/인버터와 AC 리액터를 사용한 새로운 3상 라인 인터렉터브 무정전전원장치의 개발)

  • Ji Jun-Keun;Kim Hyo-sung;Sul Seung-Ki;Kim Kyung-Hwan
    • Proceedings of the KIPE Conference
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    • 2004.07a
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    • pp.77-81
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    • 2004
  • In this paper a novel line interactive UPS (Uninterruptible Power Supply) using the two 4-leg VSCs and AC line reactor is proposed. The 4-leg Voltage Source Converter(VSC) can use the DC link voltage effectively by the 3-D SVPWM method. Hence the DC battery voltage can be reduced by $15\%$ in comparison to that of the conventional line-interactive UPS system. One VSC is in parallel with the AC line reactor of the power source side, and the other is in series with the load. The parallel 4-leg voltage source inverter controls three-phase line voltage independently in order to control the line reactor current indirectly. It eliminates the neutral line current and the active ripple power of the source side using the pqr theory so that unity power factor and the sinusoidal source current can be achieved even though both the source and the load voltages have zero sequence components. The series 4-leg voltage source inverter compensates the line voltage and allows the load voltage to be balanced and harmonic-free. Both of parallel and series 4-leg voltage source inverters always act as independently controllable voltage sources, so that three-phase output voltage shows a seamless transition to the backup mode. The feasibility of the proposed UPS system has been investigated and verified through computer simulation results.

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Characteristics comparison between air-cored and iron-cored 100 kW HTS field winding synchronous motors

  • Yoon, Jonghoon;Bong, Uijong;An, Soobin;Hahn, Seungyong
    • Progress in Superconductivity and Cryogenics
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    • v.22 no.2
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    • pp.38-43
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    • 2020
  • This paper presents comparative research on characteristics of air-cored and iron-cored high-temperature superconductor (HTS) field winding synchronous motors. The 100 kW air-cored model is designed analytically by Spatial Harmonic Method, and based on this model, the iron-cored model having the same output power is designed for comparison. Due to the substantial difference of permeability property between air and iron-core, there is a difference of magnetic field magnitude and angle with respect to the HTS tape c-axis, resulting in a different critical current of the field winding considering the anisotropic property of HTS tape. For a detailed comparison between two models, the following key motor characteristics are calculated through the Finite Element Method (FEM) simulation: 1) critical current; 2) HTS wire length; and 3) torque characteristics. From the simulation results, it can be confirmed that the critical current value of the iron-cored model increases by 33 %. Also, in the case of the superconducting wire consumption, those of the iron-cored and air-cored models are 95.3 m and 815.6 m, respectively. So the wire usage can be reduced to about 88 % by using iron core. However, in terms of torque characteristics, the torque ripple of the iron-cored model is about twice as large as that of the air-cored model, which may be a disadvantage on vibration and acoustic noise.

Driving System of 7-Phase BLDC Motor Speed Control by Fuzzy Controller (Fuzzy 제어기를 이용한 7상 BLDC 전동기 속도제어 구동시스템)

  • Yoon, Yong-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.66 no.11
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    • pp.1663-1668
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    • 2017
  • A BLDC motor with higher number of phases has several advantages, compared to the conventional three-phase BLDC motors. It can reduce the commutation torque ripple and the iron loss without increasing the voltage per phase and increase the reliability and power density. Higher number of phases increase the torque-per-ampere ratio for the same machine volume and output power by widening the electrical conduction period. In this paper, the proposed seven-phase BLDC motor drive system is made into several functional modular blocks, so that it can be easily extended to other ac motor applications: back-EMF block, hysteresis current control block, pwm inverter block, phase current block, and speed/torque control block. Also in a system of BLDC motor drive, the PI controller has been widely used in the speed controller because of the simple implementation. To obtain a good speed response in a general drive system using the PI controller, the high bandwidth of a controller is established. therefore, in this paper, a Fuzzy controller is applied to the 7-phase BLDC motor drive system in order to improve the speed control performance. The Fuzzy controller is compared with a conventional PI controller through the experiment with respect to speed dynamic responses. These experimental results show that the Fuzzy controller of the 7-phase BLDC motor drive system is superior over the conventional PI controller. The algorithm using the Fuzzy controller can improve a comfortable ride in the field of high performance 7-phase BLDC motor drive applications.

A Novel Three Level DC/DC Converter for High power applications operating from High Input Voltage (대용량 및 높은 입력전압에 적합한 새로운 Three Level DC/DC 컨버터)

  • Han S.K.;Oh W.S.;Moon G.W.;Youn M.J.
    • Proceedings of the KIPE Conference
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    • 2003.07a
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    • pp.317-322
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    • 2003
  • A novel three-level DC/DC converter (TLC)for high power applications operating from high input voltage Is proposed. Its switch voltage stress can be ensured to be only one-half of the Input voltage. Nevertheless, since all input voltage is applied to the transformer primary side, it has good turns ratio. The driving method of each module is same as those of the conventional phase-shifted ZVS full bridge PWM converter (PSFB) and the zero-voltage-switching (ZVS) of the leading leg are achieved exactly in the same manner as that of the PSFB. Moreover, its three-level operation can considerably reduce the current ripple through the output inductor and it has no problems of the DC-link voltage unbalance. Therefore, it features a low voltage stress, high efficiency, low EMI, high power density, and small sized filter. To confirm the operation, validity, and features of the proposed circuit, experimental results from a 200W, 600V/DC-48V/DC prototype are presented.

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Design of a 1.2kW 14V Low Voltage Output High Efficiency Full-Bridge DC-DC Converter (1.2kW 14V 저전압 고효율 플-브릿지 DC-DC 컨버터 설계)

  • Jang, Dong-Wook;Kim, Hoon;Kim, Hee-Jun
    • Proceedings of the KIEE Conference
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    • 2008.10b
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    • pp.524-525
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    • 2008
  • 본 논문에서는 각각의 스위치 시비율(Duty ratio)의 변화를 이용한 기존의 풀-브릿지 방식과 두 쌍의 스위치 신호 위상 변화를 이용한 위상천이 풀-브리지(Phase-shift Full-bridge) 방식의 차이점을 서술하였다. 위상천이 컨버터의 안정성을 연구하기 위하여, 출력 전류의 맥동(ripple)을 작게 하는 배전류(Current Doubler) 정류회로와 효율을 높이기 위한 동기 정류기(Synchronous Rectifier)를 포함한 평균화 된 스위치 모델을 제안한다. 이 모델을 이용하여 PSPICE 시뮬레이션을 통해 안정성을 고찰하였으며 1.2kW급 170-14V DC-DC 컨버터의 시작품을 제작 후 시뮬레이션 결과와 시작품 결과를 비교하였다. 시뮬레이션의 경우 위상여유는 $58^{\circ}$ 시작품의 위상여유는 $68^{\circ}$로 나타났으며 교차주파수는 12kHz로 동일하게 나오는 것을 확인하였다. 따라서 제안한 시뮬레이션 모델을 이용하여 실제 회로의 안정성을 예측할 수 있으며 이를 실제 회로 제작에 활용 할 수 있다.

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A New PWM-Controlled Quasi-Resonant Converter for High Efficiency PDP Sustaining Power Module (고효율의 PDP 유지 구동 전원단을 위한 새로운 펄스폭 제어방식의 쿼지 공진 컨버터)

  • Lee Woo-Jin;Choi Seong-Wook;Kim Chong-Eun;Moon Gun-Woo
    • Proceedings of the KIPE Conference
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    • 2006.06a
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    • pp.352-355
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    • 2006
  • A new PWM-controlled quasi-resonant converter for high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with hi-directional auxiliary circuit, while the main switches are operating at the fixed duty ratio and fixed switching frequency. Hence, the waveform of currents can be expected to be optimized on the conduction loss. Furthermore, the proposed converter shows the good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stress of power switches. In this paper, operational principles, analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit as PWM method.

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A New PWM-Controlled Quasi-Resonant Converter for a High Efficiency PDP Sustaining Power Module

  • Lee, Woo-Jin;Choi, Seong-Wook;Kim, Chong-Eun;Moon, Gun-Woo
    • Journal of Power Electronics
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    • v.7 no.1
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    • pp.28-37
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    • 2007
  • A new PWM-controlled quasi-resonant converter for a high efficiency PDP sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the resonant capacitor with a bi-directional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good ZVS capability, simple control circuits, no high voltage ringing problem of rectifier diodes, no DC offset of the magnetizing current and low voltage stresses of power switches. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.

Modeling of Bi-directional DC/DC Converter for Connecting DC Distribution System using EMTP (EMTP를 이용한 직류배전계통 연계용 양방향 DC/DC 컨버터 모델링)

  • Han, Joon;Kim, Doo-Ung;Oh, Yun-Sik;Gwon, Gi-Hyeon;Noh, Chul-Ho;Jung, Tack-Hyun;Kim, Chul-Hwan
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.63 no.5
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    • pp.615-621
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    • 2014
  • With development of electrical power system, the DC distribution system has been considered as a promising technology to be used in the future smart distribution system. Among the various components comprising the DC distribution system, the bi-directional DC/DC converter is one of the most important equipment to interconnect between main power system and various renewable resources such as photovoltaic power generation, wind power generation, and electrical vehicles. In this paper, a bi-directional DC/DC converter based on three-phases interleaved method which is effective to reduce ripple of input current and output voltage is modeled using ElectroMagnetic Transient Program(EMTP), and the verification of modeled bi-directional DC/DC converter is conducted.

A Novel Dual-Input Boost-Buck Converter with Coupled Inductors for Distributed Thermoelectric Generation Systems

  • Zhang, Junjun;Wu, Hongfei;Sun, Kai;Xing, Yan;Cao, Feng
    • Journal of Power Electronics
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    • v.15 no.4
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    • pp.899-909
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    • 2015
  • A dual-input boost-buck converter with coupled inductors (DIBBC-CI) is proposed as a thermoelectric generator (TEG) power conditioner with a wide input voltage range. The DIBBC-CI is built by cascading two boost cells and a buck cell with shared inverse coupled filter inductors. Low current ripple on both sides of the TEG and the battery are achieved. Reduced size and power losses of the filter inductors are benefited from the DC magnetic flux cancellation in the inductor core, leading to high efficiency and high power density. The operational principle, impact of coupled inductors, and design considerations for the proposed converter are analyzed in detail. Distributed maximum power point tracking, battery charging, and output control are implemented using a competitive logic to ensure seamless switching among operational modes. Both the simulation and experimental results verify the feasibility of the proposed topology and control.