• Title/Summary/Keyword: Constant current

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Research on Variable Constant Current Efficiency Measuring Device for Solar Panel to Reuse (태양광 패널 재사용을 위한 가변 정전류 기반의 효율 측정장치에 관한 연구)

  • Sang-Jin Woo;Dae-Heon Kim;Jae-Jin Lee;Oh-Min Kwon
    • IEMEK Journal of Embedded Systems and Applications
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    • v.18 no.1
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    • pp.9-17
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    • 2023
  • This paper relates to the development of a device for measuring the efficiency of a solar panel based on a variable constant current, and proposed a standard for reuse of the solar panel. By applying a variable constant current circuit to a solar panel efficiency measuring device, it was easy to apply a maximum power point tracking (MPPT) algorithm. In addition, a load dispersion method was applied to measure the efficiency of a high-capacity solar panel. and it is possible to solve a problematic thermal runaway during a MOSFET parallel operation by applying the load dispersion method. As a result of the experiment, the solar panel efficiency measuring device was able to accommodate a large solar panel of 350W, which is the maximum measurement goal. In this paper, the validity was confirmed through the 310W solar panel efficiency measurement experiment collected after removal.

A Rail-to-Rail CMOS Op-amp with Constant Gain by Using Output Common Mode Current Compensation (출력 단 공통모드 전류 보상으로 일정한 이득을 갖는 Rail-to-Rail CMOS 연산증폭기)

  • Lee, Dong-Geon;Jeong, Hang-Geun
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.457-458
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    • 2008
  • This paper presents an output common mode current compensation method to achieve both constant Gm and constant gain. A conventional rail-to-rail CMOS op-amp with constant Gm was designed by using complementary differential input stage and current compensation skills. But it doesn't operate constant gain, because of output resistance variation. With $0.18{\mu}m$ CMOS process, the simulation results show that the differential gain variation can achieve less than 1.3dB. And a 60dB gain, a 13.5MHz unity gain-frequency, and 1mW power consumption, when operating at 1.8V and 10pF load.

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Input Current Harmonic Reduction of Inverer TIG Welder (인버터 TIG용접기의 전원전류 고조파 저감)

  • 김준호
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.560-563
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    • 2000
  • In this paper we proposed AC/DC boost converter to improve input current harmonic reduction in TIG welder. The proposed harmonic reduction circuit with UC2854AN acting on constant switching frequency average current control has a three-loop control structure : the inner current loop the line voltage feed-forward loop and th outer voltage loop. Also we applied the constant current strategy on full bridge IGBT inverter to stabilized the output current using the analog PI controller. To demonstrate the practical significance of the proposed methods some simulation studies and experimental results are presented.

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Alternating Current (AC) Powered LED Lighting Technology with Constant Brightness (빛의 밝기가 일정한 교류 구동 LED 조명기술)

  • Lee, Dong Won;Ahn, Ho-Myoung;Kim, Byungcheul
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.35 no.5
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    • pp.466-470
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    • 2022
  • In order to widely disseminate LED lighting, LED lighting technology that directly uses AC commercial power has been recently introduced. AC powered LED lighting technology has a problem in that the light brightness of the LED changes because the voltage applied to the LED and the current flowing through the LED continuously change. In this study, when the LED current is greater than the design current, the current control signal generated by the controller is supplied to the current source to supply only the design current to the LED by increasing the voltage drop at the current source. If it is smaller than the design current, the controller is adjusted so that the current is supplied only to the LED without a voltage drop in the current source. It can be seen that the higher the maximum rectified voltage, the faster the lighting time of the LED light emitting block is, so that the power factor of the LED lighting is improved. The LED lighting technology proposed in this study enables LED lighting with constant light brightness, reduced power consumption, and long lifetime.

Current Controlled PWM for Multilevel Voltage-Source Inverters with Variable and Constant Switching Frequency Regulation Techniques: A Review

  • Gawande, S.P.;Ramteke, M.R.
    • Journal of Power Electronics
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    • v.14 no.2
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    • pp.302-314
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    • 2014
  • Due to advancements in power electronics and inverter topologies, the current controlled multilevel voltage-source pulse width modulated (PWM) inverter is usually preferred for accurate control, quick response and high dynamic performance. A multilevel topology approach is found to be best suited for overcoming many problems arising from the use of high power converters. This paper presents a comprehensive review and comparative study of several current control (CC) techniques for multilevel inverters with a special emphasis on various approaches of the hysteresis current controller. Since the hysteresis CC technique poses a problem of variable switching frequency, a ramp-comparator controller and a predictive controller to attain constant switching frequency are described along with its quantitative comparison. Furthermore, various methods have been reviewed to achieve hysteresis current control PWM with constant switching frequency operation. This paper complies various guidelines to choose a particular method suitable for application at a given power level, switching frequency and dynamic response.

Effects of Electric Current and Potential on the Electrokinetic Removal of Heavy Metals from an Abandoned Mine Tailings

  • Shin, Hyun-Moo;Lee, Chang-Eun
    • Journal of Environmental Science International
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    • v.13 no.2
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    • pp.149-159
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    • 2004
  • In the removal of heavy metals from the mine deposit using electrokinetic processes, the effects of operation under both constant current and constant potential conditions were estimated. The results of soil pH distributions for DDW-20 V and DDW-100 mA cases after the electrokinetic remediation tests were observed. In the former case, soil pH was not much changed and kept to almost constant value just little higher than initial soil pH of 3.52, except near the cathode, which was about pH 5. While in the latter case, soil pHs of anode and the cathode regions were less than pH 3 and about 6, respectively. The electroosmotic flow to the cathode increased rapidly till 10 hrs and decreased steadily and then maintained to constant rate until the end of operation at constant current condition. Electric potential gradient was continuously increased to as much as 34.375 V/cm. At the steady state, values of the apparent electric conductivity for DDW-20 V and DDW-100 mA were around 40 ${\mu}\textrm{s}$/cm and 30 ${\mu}\textrm{s}$/cm, respectively. In the DDW-100mA test, Cu, Cd, and Zn except Pb showed the tendency of moving toward the cathode. While in the DDW-20 V case, it was observed that Cu, Zn, and Pb except Cd were not moved to any directions. The results of the tests demonstrated that the electrokinetic soil remediation process could be operated better under constant current condition than constant electric potential condition.

Characteristic of Hydrogen-oxygen Mixed Gas Power Conversion System (혼합수소발생기용 전력변환장치의 특성)

  • Mun, Sang-Pil;Lee, Hae-Su;Nakaoka, Mutsuo;Jeong, Jang-Geun;Kim, Chang-Il;Jo, Gil-Je;Kim, Sang-Don
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2007.11a
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    • pp.323-326
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    • 2007
  • In this paper, the basic experiment, electrolytic cell design and basic manufacturing have been made to interpret the characteristics of Hydrogen-Oxygen-Gas-Generator. As for the detailed matters, the data research on basic technology on Hydrogen-Oxygen-Gas and analysis on characteristics of Hydrogen-Oxygen-Gas from basic experiment. Also the experiment of characteristics and comparative evaluation between constant current source using SCR converter from existing method and constant current source using new phase shift PWM control method converter. As results when it has injected constant DC current, we has compared Gas quantities by variable ripple frequencies using phase shift PWM control method converter. Therefore, in linear region, it has not different Gas quantities by constant DC current and by phase shift PWM control method converter. Also, it has increased Gas quantities wilder linear region when put ripple frequency at saturation region. Through, Gas quantities and input rower, it has acquired higher input power per Gas quantities at put pulse current. Therefore, when designing converter or inverter for electrolysis, which has ripple current.

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Design of an Integrated Current-Voltage Charging Compensator for the LLC Resonant Converter-Based Li-ion Battery Charger (LLC 공진형 컨버터 기반 리튬이온 배터리 충전기의 통합 전류-전압 보상기 설계방법 연구)

  • Choi, Yeong-Jun;Choi, See-Young;Kim, Rae-Young
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.2
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    • pp.126-133
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    • 2017
  • The conventional battery charger requires two separate voltage and current compensators to achieve constant current and constant-current-charging profile. This compensator configuration leads to an inevitable transient response during the mode change between the constant current and the constant voltage operation. Futhermore, a tedious and complicated design process is required to consider a widely changing battery voltage and the nonlinear electrical properties of Li-ion battery. This study proposes a single integrated voltage-current compensator of the LLC resonant converter for Li-ion battery charger applications to overcome the aforementioned drawbacks. The proposed compensator is designed to provide a smooth and reliable performance during the entire charging process while providing the reduced design efforts and seamless mode transient response. Several experimental results based on a 300 W prototype converter and its theoretical analysis are provided to verify the effectiveness of the proposed compensator.

Design of a High-Precision Constant Current AC-DC Converter with Inductance Compensation

  • Chang, Changyuan;Xu, Yang;Bian, Bin;Chen, Yao;Hu, Junjie
    • Journal of Power Electronics
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    • v.16 no.3
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    • pp.840-848
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    • 2016
  • A primary-side regulation AC-DC converter operating in the PFM (Pulse Frequency Modulation) mode with a high precision output current is designed, which applies a novel inductance compensation technique to improve the precision of the output current, which reduces the bad impact of the large tolerance of the transformer primary side inductance in the same batch. In this paper, the output current is regulated by the OSC charging current, which is controlled by a CC (constant current) controller. Meanwhile, for different primary inductors, the inductance compensation module adjusts the OSC charging current finely to improve the accuracy of the output current. The operation principle and design of the CC controller and the inductance compensation module are analyzed and illustrated herein. The control chip is implemented based on a TSMC 0.35μm 5V/40V BCD process, and a 12V/1.1A prototype has been built to verify the proposed control method. The deviation of the output current is within ±3% and the variation of the output current is less than 1% when the inductances of the primary windings vary by 10%.