• 제목/요약/키워드: Unity power factor

검색결과 326건 처리시간 0.023초

축소차원 Luenberger 관측기를 이용한 단산 PWM 컨버터의 고역률 제어 (The Control of Single Phase Power Factor PWM converter using Reduced-Order Luenberger Observer)

  • 양이우;이용근;김영석
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1999년도 전력전자학술대회 논문집
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    • pp.485-488
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    • 1999
  • In this paper, a current control system for single phase PWM AC/DC converter without the source voltage sensors is proposed. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimation of source voltage is performed by the reduced-order Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by experiments.

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축소차원 Luenberger 관측기를 이용한 단상 PWM 컨버터의 고역율 제어 (The Control of Single Phase High Power Factor PWM converter using Reduced-order Luenberger Observer)

  • 양이우;유지용;김영석
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 연구회 합동 학술발표회 논문집
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    • pp.78-82
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    • 1998
  • In this paper, the authors propose a current control system of single phase PWM AC/DC converter without the source voltage sensors. The sinusoidal input current and unity effective power factor are realised based on the estimated source voltage in the controller. The estimations of source voltage are performed based on the reduced-order Luenberger observer using actual currents. The estimated source voltage is used to accomplish unity power factor. The proposed method is proved by simulations

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계통연계형 태양광 발전 시스템에서의 전원측 역율 개선 (Source Side Power Factor Correction for Utility Interactive Photovoltaic System)

  • 조영준;김홍성;목형수;최규하;김한성
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1997년도 전력전자학술대회 논문집
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    • pp.386-392
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    • 1997
  • Recently, according to developing industry and life style, power consumption have been increased year after year. Currently these much power demand from power consumer is weakening the allowable power reserve margin in summer. As one of the remedies about this problem, the small scale utility interactive photovoltaic system(UIPVS) is considered for auxiliary power source. For this system one of problems to be solved technically, system operating power factor. Generally in case of small scale system, system is operated in unity power factor. But this unity power factor operating mode decrease power factor viewed from utility because UIPVS supply active power to utility. Therefore this paper propose UIPVS with power factor correcting function and this system is analyzed.

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승압인덕턴스 분산형 PWM 정류기 (Boosting Inductor Distribution Type PWM Rectifier)

  • 이무영;김우현;마진석;임성운;권우현
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 F
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    • pp.1940-1943
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    • 1998
  • A new PWM rectifier which offers a unity power factor is proposed. The circuit has same inductance as the conventional boosting type PWM rectifier in powering mode, but the inductance is splitted to 2 part in freewheeling mode. So the period of freewheeling mode is shorter than that of conventional boosting type PWM rectifier, and discontinuous input current is obtained in wide duty range. Therefore the proposed PWM rectifier accomplishs a unity power factor in wide range of duty ratio and boosting factor. And the conventional boosting type PWM rectifier has poor power factor near the unity boosting ratio, the proposed PWM rectifier improves this problem. The mathmatical analysis are presented and experimental results are given.

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Unity Power Factor Control of SRM Drive

  • Park, Sung-Jun;Lee, Dong-Hee;Ahn, Jin-Woo;Kim, Cheul-U
    • KIEE International Transaction on Electrical Machinery and Energy Conversion Systems
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    • 제11B권4호
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    • pp.193-199
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    • 2001
  • This paper suggests a novel single-stage drive for a switched reluctance motor (SRM) to achieve sinusoidal, near unity power factor input currents. The proposed drive is very simple without additional active switch. As a single-stage approach, which combines a DC link capacitor used as dc source and a drive used for driving the motor into one power stage, a simple structure and low cost drive in implemented. A prototype drive for an 8/6 pole SRM equipping a suitable encoder is designed to evaluate the proposed topology. Also subscription control algorithm is presented. The characteristics and validity of the proposed circuit will be discussed in depth through the experimental results.

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A BIFUNCTIONAL UTILITY CONNECTED PHOTOVOLTAIC SYSTEM WITH POWER FACTOR CORRECTION AND U.P.S. FACILITY

  • Kim. S.;Yoo, Gwonjong;Song, Jinsoo
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
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    • pp.103-108
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    • 1996
  • In this paper, a novel utility connected photovoltaic power generation system with unity power factor and uninterruptable power system facility and its control strategy are proposed. The proposed photovoltaic(PV) system is connected in parallel between utility and load. The PV system provides an uninterruptable voltage to load, a maximum power tracking to solar array, and power factor correction to the utility. The proposed system has the following advantages compared with the conventional utility connected PV system. 1. Harmonic elimination Function 2. Feeding the photovoltaic energy to the utility 3. Providing the uninterruptible power source along battery to the load In case that the photovoltaic array system is on the poor power generation, the battery and capacitor of the PV system are charged by three phase utility source and the inverter in the PV system only provides the reactive current to eliminate the harmonic current exited on the utility. In the normal operation mode, the PV system supplies active power to load and reactive power to utility in order to maintain the unity power factor and to regulate ac load voltage.

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확장된 동작 영역을 갖는 3상 전압원 PWM 컨버터 제어 (Control of a Three-Phase Voltage-Source PWM Converter with an Extended Operation Region)

  • 민동기;안성찬;현동석
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1997년도 전력전자학술대회 논문집
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    • pp.9-13
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    • 1997
  • In this paper, the operation regions of a three-phase voltage-source PWM converter are defined: linear modulation region, allowed current region, linear control region, unity power-factor region, and power-factor decreasing region. Particularly, the power-factor decreasing region is first examined and defined as the region where both the sinusoidal input current control and the stable DC link voltage regulation can not be obtained with a unity power-factor operation. To avoid these undesirable effects, the optimal current vector is derived, which ensures the sinusoidal input current and the stable DC link voltage regulation with maximum power-factor available, and, in consequence, it extends the operation region of the PWM converter. The validity of the proposed control scheme is proved by the computer simulation.

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High-Efficiency Power Conditioning System for Grid-Connected Photovoltaic Modules

  • Choi, Woo-Young;Choi, Jae-Yeon
    • Journal of Power Electronics
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    • 제11권4호
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    • pp.561-567
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    • 2011
  • This paper presents a high-efficiency power conditioning system (PCS) for grid-connected photovoltaic (PV) modules. The proposed PCS consists of a step-up DC-DC converter and a single-phase DC-AC inverter for the grid-connected PV modules. A soft-switching step-up DC-DC converter is proposed to generate a high DC-link voltage from the low PV module voltage with a high-efficiency. A DC-link voltage controller is presented for constant DC-link voltage regulation. A half-bridge inverter is used for the single-phase DC-AC inverter for grid connection. A grid current controller is suggested to supply PV electrical power to the power grid with a unity power factor. Experimental results are obtained from a 180 W grid-connected PV module system using the proposed PCS. The proposed PCS achieves a high power efficiency of 93.0 % with an unity power factor for a 60 Hz / 120 Vrms AC power grid.

A Sliding Mode Control Design based on the Reaching Law for Matrix Rectifiers

  • Wang, Zhiping;Mao, Yunshou;Hu, Zhanhu;Xie, Yunxiang
    • Journal of Power Electronics
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    • 제16권3호
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    • pp.1122-1130
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    • 2016
  • This paper presents a novel approach for achieving both a tight DC voltage regulation and a power factor control by applying the Reaching Law Sliding Mode Control (RL-SMC) and the conventional Sliding Mode Control (SMC). Applying these strategies on a matrix rectifier (MR) can achieve a unity grid side power factor when the DC load changes widely and it can provide a ripple-free output voltage that is easily affected by distortions of the three-phase ac voltage supply. Furthermore, by employing the reaching law on the SMC can solve the chatting problem of the sliding motion. Comparative Matlab simulations and experimental verifications for these strategies have been presented and discussed in this paper. The results show that by applying the SMC and RL-SMC on a MR can achieve a unity grid side power factor and a regulated ripple-free DC output.

인버터 용접기용 3상 SMR의 운전특성에 관한 연구 (A Study on Operation Characteristics of 3-Phase SMR for Inverter Welding System.)

  • 채영민;고재석;최해룡;김진욱;최규하
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1997년도 전력전자학술대회 논문집
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    • pp.49-54
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    • 1997
  • One of the drawbacks of using diode-bridge rectifiers in the unity interface, is the line-current harmonic distortion caused by the nonlinear nature of the rectifier operation. So, a PWM converter for the power factor correction is analysed for unity power factor as well as low cost design, which enable to meet the limits of international standards.

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