• Title/Summary/Keyword: Current mode PWM

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Overmodulation Characteristics of Carrier Based MVPWM for Eliminating the Leakage Currents in Three-Level Inverter (3-레벨 인버터의 누설전류 제거를 위한 캐리어 기반 MVPWM의 과변조 특성)

  • Lee, Eun-Chul;Choi, Nam-Sup;Ahn, Kang-Soon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.20 no.6
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    • pp.509-516
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    • 2015
  • The overmodulation characteristics of a carrier-based medium vector pulse width modulation (CBMVPWM) are examined in this study. CBMVPWM can completely eliminate leakage currents in a three-phase, three-level inverter using only the switching states with the same common mode voltage even in an overmodulation operation. The analytic equations for the magnitude of the output voltage and the switching frequency are derived for overmodulation operation, and the effect of dead time on the leakage current is demonstrated. This study presents the operating principle of CBMVPWM, basic overmodulation features, and simulations and experiments for operating verification.

Power Factor Correction of Single-phase PWM Converter using Third Harmonic Injection (3차 고조파 주입에 의한 단상 PWM컨버터의 고역률 제어)

  • 손진근;유성식;김병진;박종찬;전희종
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.13 no.3
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    • pp.25-33
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    • 1999
  • In this paper, the method of reducing hanmnics and correcting of power factor in single PWM converter associated with diode rectifier and boost converter is studied. In the general diode rectifier there are sorre problems that discontinuous current of reducing power factor and including distortion of hanmnics at the input current affects other sources. To solve the problems of performance degradation due to pulse wavefonn in the input current, the ac-dc converter in which the hanmnic distortion in the input current is reduced using a third-hanmnic-injected PWM is proposed. A lower power loss of switching and easy configuration of circuit are obtained by adopting discontinuous current mode. Simulation and experimental results of ac-dc converter with 5[kHz] switching frequency are presented and correction of power factor and reduction of total hanmnic distortion was established.lished.

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A White-LED Driver IC for Mobile Applications (모바일용 White-LED Driver IC)

  • Ko, Young-Seok;Park, Shi-Hong
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.04b
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    • pp.39-40
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    • 2009
  • This paper presents a white-LED driver IC for a mobile application. It uses a high efficiency current mode boost converter method for a low voltage application. For a LED drive, it provides a PWM(Pulse Width Modulation) and analog dimming function. The device was designed and fabricated using 0.35um BCD process. The evaluated waveforms for an implemented IC show promising results.

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Design of Triple Loop Current Control for Auxiliary Power Unit of Fuel Cell Train having Grid Connected Inverter Function (계통 연계 기능을 갖는 연료전지 철도차량 보조전원장치의 삼중 루프 전류 제어기 설계)

  • Kwon, Il-Seob;Baek, Seung-Woo;Kim, Hag-Wone;Cho, Kwan-Yual
    • The Transactions of the Korean Institute of Power Electronics
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    • v.25 no.4
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    • pp.293-302
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    • 2020
  • This study proposes a triple-loop current control method for the auxiliary power unit of fuel cell trains. The auxiliary power unit of fuel cell trains has a grid-connected function when power is supplied to the utility grid. Moreover, the auxiliary power unit of trains has a 1500 V DC link voltage; thus, PWM frequency cannot be increased to a high frequency. Owing to this low PWM frequency condition, creating a triple-loop design is difficult. In this study, a triple-loop controller is developed for a capacitor voltage controller in standalone mode that operates as an auxiliary power supply for trains and for a grid current controller in grid control mode with an inner capacitor voltage controller. The voltage controller employs an inductor current controller inner loop. To overcome low PWM frequency, a design method for the bandwidth of the capacitor voltage controller considering the bandwidth of the inner inductor current controller is described. The effectiveness of the proposed method is proven using PSIM simulation.

A Design of PFM/PWM Dual Mode Feedback Based LLC Resonant Converter Controller IC for LED BLU (PFM/PWM 듀얼 모드 피드백 기반 LED BLU 구동용 LLC 공진 변환 제어 IC 설계)

  • Yoo, Chang-Jae;Kim, Hong-Jin;Park, Young-Jun;Lee, Kang-Yoon
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.267-274
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    • 2013
  • This paper presents a design of LLC resonant converter IC for LED backlight unit based on PFM/PWM dual-mode feedback. Dual output LLC resonant architecture with a single inductor is proposed, where the master output is controlled by the PFM and slave output is controlled by the PWM. To regulate the master output PFM is used as feedback to control the frequency of the power switch. On the other hand, PWM feedback is used to control the pulse width of the power switch and to regulate the slave output. This chip is fabricated in 0.35um 2P3M BC(Bipolar-CMOS-DMOS) Process and the die area is $2.3mm{\times}2.2mm$. Current consumptions is 26mA from 5V supply.

Transformer-less Inverter for Photovoltaic and small unit Windturbine System (태양광 및 소단위 풍력발전용 변압기 없는 인버터)

  • 박영산;김윤식;이성근;안병원;배철오
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.333-336
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    • 2003
  • Designed transformer-less inverter for photovoltaic and small unit windturbine power system. This system consisted of boost chopper circuit of multiple-switching method and foil bridge PWM inverter. Transformer-less system was adapted to reduce cost and size. But in this system, earth-leakage current have to be considered. So, to solve this problem, we used PWM inverter switching method to reduce the earth-leakage current which flows in accordance with the variation of DC input common mode voltage.

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A Comparative Study of Simple Ac-Dc PWM Full-Bridge Current-Fed and Voltage-Fed Converters

  • Moschopoulos Gerry;Shah Jayesh
    • Journal of Power Electronics
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    • v.4 no.4
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    • pp.246-255
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    • 2004
  • Ac-dc PWM single-stage converters that integrate the PFC and dc-dc conversion functions in a single switching converter have been proposed to try to minimize the cost and complexity associated with implementing two separate and independent switch-mode converters. In this paper, two simple ac-dc single-stage PWM full-bridge converters are considered - one current-fed, the other voltage-fed. The operation of both converters is explained and their properties are noted. Experimental results obtained from simple lab prototypes of both converters are presented, then compared and discussed.

A Square Wave Current Compensation of Current Source Induction Motor drives Using Active Power Filter (능동 전력 필터에 의한 유도모터 구동 전류형 인버터의 구형파 전류보상)

  • 정영국
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.133-136
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    • 2000
  • Current Source Inverter(CSI) operated in square wave mode is more efficient than the PWM CSI because of increased cost greater complexity of control algorithm, and substantial switching losses EMI. But the square wave output current of CSI rich in low order harmonics produce motor torque ripples. Therefore in this paper describes the active power filters for square wave current compensation of current source induction motor. Also extended current synchronous detection(ECSD) as compensation algorithm is proposed. To confirm the validity o proposed system some simulation results are presented and discussed.

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Current-induced Phase Demodulation Using a PWM Sampling for a Fiber-optic CT

  • Park, Hyoung-Jun;Lee, June-Ho;Kim, Hyun-Jin;Song, Min-Ho
    • Journal of the Optical Society of Korea
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    • v.14 no.3
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    • pp.240-244
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    • 2010
  • In this work, we used PWM sampling for demodulation of a fiber-optic interferometric current transformer. The interference signal from a fiber-optic CT is sampled with PWM triggers that produce a 90-degree phase difference between two consecutively sampled signals. The current-induced phase is extracted by applying an arctangent demodulation and a phase unwrapping algorithm to the sampled signals. From experiments using the proposed demodulation, we obtained phase measurement accuracy and a linearity error, in AC current measurements, of ~2.35 mrad and 0.18%, respectively. The accuracy of the proposed method was compared with that of a lock-in amplifier demodulation, which showed only 0.36% difference. To compare the birefringence effects of different fiber-optic sensor coils, a flint glass fiber and a standard single-mode fiber were used under the same conditions. The flint glass fiber coil with a Faraday rotator mirror showed the best performance. Because of the simple hardware structure and signal processing, the proposed demodulation would be suitable for low-cost over-current monitoring in high voltage power systems.

Reduction of Conducted Emission in Interleaved RPWM Buck Converter (인터리브드 RPWM Buck 컨버터의 전도성 노이즈 감소에 대한 연구)

  • Lee, Seunghyun;Lee, Keunbong;Nah, Wansoo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.28 no.4
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    • pp.298-308
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    • 2017
  • This paper presents a Interleaved Buck Converter(IBC) system with Random PWM to reduce electromagnetic noise by harmonics. Swithced mode power supply generally controlled by high switching frequency have a electromagnetic interference(EMI) issue due to the high-voltage/high-current switching to regulate the voltage in buck converter. To solve the problem. we present a novel IBC system with PRBS. IBC system has two active switches with 180 phase difference that controll the cicuit with two PWM signal. IBC system may be disadventageous for the cost due to the addtion of one set of switch, but it has adventages of power distribution, current ripple cancellation, fast transient response, and passive component size reduction. To verify the validity of study, simulation program has been bulit using PSIM and the experimental results of IBC system using RPWM was compared with the conventinal PWM and randomized PWM.