• Title/Summary/Keyword: Unity power factor

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Study on grid-connected photovoltaic 3 kW Inverter (3kW급 계통 연계형 태양광 인버터에 관한 연구)

  • Song, S.G.;Lee, S.H.;Park, S.J.
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.707-710
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    • 2005
  • This paper presents a 3kW grid-connection photovoltaic power generation system and its topology. Photovoltaic system must provide the sinusoidal output voltage wave for unity power factor High frequency switching converters are becoming more popular because of several benefits which are essential in power conversion system. This paper introduces a high speed digital controller using TMS320F2812 DSP chip which can be used for high frequency switching converters. The experimental results of the proposed PWM Inverter demonstrates its high performance with unity input power factor having very low distorsion in input current waveforms and good dynamic characteristics at full load.

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Sensorless MPPT Control using a Boost Converter and a Grid Side Inverter in Wind Power Generation Systems (Boost 컨버터와 계통연계 인버터를 이용한 풍력발전의 센서리스 MPPT 제어)

  • Kim, Do-Yoon;Lee, Jun-Min;Kim, Young-Seok
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.7
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    • pp.1372-1377
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    • 2011
  • This paper proposes the control method of MPPT(maximum power point tracking) for the wind energy generation system using the duty ratio control of boost type DC-DC converter. For a lower cost and a higher reliability, the wind and the generator velocity sensors are removed. MPPT control is implemented by changing the duty ratio of the boost converter. Chain rule is applied by using each function. The grid side inverter is controlled to regulate unity power factor. The proposed control method was analyzed mathematically and verified by the computer simulation using PSIM.

A filed operation characteristics and the controversial point of Photovoltaic power generation system (태양광 발전시스템의 현장 운전특성 및 문제점)

  • Koh, Kang-Hoon;Suh, Ki-Young;Lee, Hyun-Woo;Hong, Doo-Sung;Gang, Yeong-Cheol;U, Jung-In
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.381-383
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    • 2000
  • The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper presents a three phase inverter for photovoltaic power system with current controller, voltage controller, PLL control system and the phase detector of interactive voltage by using da transformation. The proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor. The results of the operated from January to October show the system characteristics.

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Novel High Power Factor Correction Circuit for Low-Cost Electronic Ballasts (저가격 형광등용 전자식 안정기에 적합한 새로운 역률개선회로)

  • Chae, Gyun;Youn, Yong-Sik;Cho, Gyu-Hyeong
    • Proceedings of the KIEE Conference
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    • 1997.07f
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    • pp.2072-2074
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    • 1997
  • A new low-cost high power factor correction circuit for electronic ballasts is proposed. The proposed circuit provides good power factor correction, low current harmonic distortion and cost-effectiveness. The prototype meets the IEC555-2 requirements satisfactorily with nearly unity power factor.

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Design of High Quality Regulator with High Efficiency Based on Half-Bridge Topology (하프 브릿지 컨버터를 기반으로 한 고효율을 갖는 고역률 정류기의 설계)

  • 이준영;문건우;정영석;윤명중
    • Proceedings of the KIPE Conference
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    • 1997.07a
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    • pp.400-409
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    • 1997
  • Design of single stage AC/DC converter with high power factor and high efficiency based on half-bridge topology for low power application is proposed. To obtain design equations, modelling and detailed analysis are performed. The proposed converter gives and power factor and high efficiency by employing aynchronous rectifiers. To verify the performances of the proposed converter 90W-converter has been designed. This prototype converter meets IEC555-2 requirements with near unity power factor.

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Zero-Voltage-Transition PWM Single-Phase Rectifier with Reduced Conduction Loss and Unity Power Factor (고역율 및 저도통손을 갖는 ZVT PWM 단상 정류기)

  • Choi, S.H.;Lee, B.C.;Paeng, S.H.;Kim, I.D.;Nho, E.C.
    • Proceedings of the KIPE Conference
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    • 2005.07a
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    • pp.546-548
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    • 2005
  • This paper proposes a unity power factor ZVT PWM single-phase rectifier. The ZVT soft switching are achieved by using a simple ZVT circuit, and the reduced conduction losses are achieved by employing a single-stage converter, instead of a typical double-stage converter composed of front end diode rectifier and cascaded boost rectifier. Furthermore, thanks to good features such as simple PWM control at constant frequency, low switch stress and low VAR rating of commutation circuits, it is suitable for high power applications. The principle of operation is explained in detail, and simulation results of the new converter are also included.

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New Control Seheme for AC-DC-AC Converters without DC Link Electrolytic Capacitor (직류링크 전해커패시터 없는 AC-DC-AC 컨버터 재어에 관한 연구)

  • 김준석;설승기
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.43 no.3
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    • pp.397-408
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    • 1994
  • In this paper, a novel concept for a static three-phase to three-phase power converter for an AC drive with a unity power factor and reduced harmonics on the utility line is presented. The power circuit consists of two back-to-back connected six-pulse bridges having only a $\mu$F ceramic capacitor in the DC link. By controlling the active kpower balance between two bridges, the DC link voltage can be maintained within 20V deviation from the nominal value with the small ceramic capacitors regardless of the load variation even in the unbalanced source condition.

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Control Characteristics of Three-Phase Utility Interactive Phovotovoltaic Power Generation System (3상 계통연계 태양광발전시스템의 운전특성)

  • Kim, Yeong-Cheol;Jeong, Myeong-Ung;Seo, Gi-Yeong;Lee, Hyeon-U;U, Jun-In
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.49 no.8
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    • pp.536-543
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    • 2000
  • The photovoltaic power generation system has a great future as clean energy instead of fossil fuel which has many environmental problems such as exhausted gas or air pollution. In a utility interactive photovoltaic generation system, a three-phase inverter is used for the connection between the photovoltaic array and the utility. This paper present a three phase inverter for photovoltaic power system with current controller, voltage controller, PLL Control system and the Phase detector of Interactive Voltage by using dq transformation. The proposed inverter system provides a sinusoidal ac current for domestic loads and the utility line with unity power factor.

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A Study on the Power Factor Improvement of DC Power Regenerating Systems Using SVPWM (SVPWM을 이용한 직류전력 회생시스템의 역률개선에 관한 연구)

  • Ko, Young-Min;Chae, Soo-Yong;Seo, Young-Min;Jeong, Dae-Taek;Bae, Young-Wook;Hong, Soon-Chan
    • Proceedings of the KIPE Conference
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    • 2007.07a
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    • pp.196-198
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    • 2007
  • In the substations for traction systems and the large-scale discharging system of secondary batteries, the voltage of DC bus line goes up by the regenerated energy and the energy is usually wasted in resistor for system stability. This paper proposes the DC power regenerating system using a three phase PWM inverter. The proposed system can regenerate the excessive DC power from DC bus line to AC supply and control the power factor of AC supply to unity. To implement unity power factor, the magnitude of the inverter output voltage should be higher than that of AC supply and therefore SVPWM technique is adopted. Computer simulations are carried out to verify the validity of the proposed system.

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Comparison and analysis of control algorithms of single-phase AC/DC parallel converters (단상 AC/DC 병렬 컨버터 제어 알고리즘의 비교, 분석)

  • 이강희
    • Proceedings of the KIPE Conference
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    • 2000.07a
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    • pp.290-293
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    • 2000
  • In this paper the algorithm which controls output voltage and power factor independently and the algorithm which controls output voltage with fixed unity power factor are compared and analyzed. These algorithms are applied to single-phase AC/DC parallel are applied to single-phase AC/DC parallel converters for a high speed train system. The control characteristic of the algorithms are compared and analyzed with respect to the output voltage and input power factor when system parameters vary.

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