• Journal of Power Electronics
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• 제14권6호
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• pp.1217-1223
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• 2014

A novel half load-cycle worked dual input single output (DISO) DC/AC inverter is presented. The basic circuit consists of a dual buck regulator, which works in continuous current mode. The working principle of DISO DC/AC inverter has been used. The control method applied for half load-cycle worked DISO DC/AC inverter has been studied. The control effects of the open-loop proportional control and closed-loop proportional-integral control are compared by using PSIM software. The parameters are adopted in the realistic simulation and experiment test. Moreover, the waveforms, such as voltage of modulation reference signal and output voltage, were given. The simulation and experiment results proved that the half load-cycle worked DISO DC/AC inverter could achieve good performance, gain a line frequency of 50 Hz, and verify the correctness of theoretical analysis.

• Journal of Power Electronics
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• 제4권4호
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• pp.205-216
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• 2004

In this paper, a three-phase induction machine-based wind power generation scheme is proposed. This scheme uses a low-cost diode bridge rectifier circuit connected to an induction machine via an ac load voltage regulator (AC-LVR) to regulate dc power transfer. The AC-LVR is used to regulate the DC load voltage of the diode bridge rectifier circuit which is connected to the three-phase self-excited induction generator (SEIG). The excitation of the three-phase SEIG is supplied by the static VAR compensator (SVC). This simple method for obtaining a full variable-speed wind turbine system by applying a back-to-back power converter to a wound rotor induction generator is useful for wind power generation at widely varying speeds. The dynamic performance responses and the experimental results of connecting a 5kW 220V three-phase SEIG directly to a diode bridge rectifier are presented for various loads. Moreover, the steady-state simulated and experimental results of the PI closed-loop feedback voltage regulation scheme prove the practical effectiveness of these simple methods for use with a wind turbine system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 하계학술대회 논문집
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• pp.459-461
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• 1991

This paper proposes a novel AC voltage regulator topology. The output voltage is varied by controlling voltage drop of the transformer which is connected with load in series. The waveform of output voltage is clamped sinusoidal, then harmonic components are remarkably decreased compared with conventional phase control method. The feasibility of proposed topology is verified experimentally.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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• pp.547-553
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• 1998

In this paper, we composed of utility interactive pv generation system of voltage source inverter, and represented uninterrutible power supply (UPS) equipment maintaining constant voltage, using a pulse width modulation(PWM) voltage fed inverter, as power source disconnection, voltage variation and output current variation with load variation. This system is driven by being synchronized voltage fed inverter and AC source, and in the steady state of power source charge battery connected to dc side with solar cell using a photovoltaic (PV) that it was so called constant voltage charge. In addition, better output waveform was generated because of PWM method, and it was proved to test by experiment maintained constant output voltage regardless of AC source disconnection, load variation, and voltage variation of AC power source.

• 조명전기설비학회논문지
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• 제21권3호
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• pp.96-106
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• 2007

동기발전기의 출력전압은 여자 시스템의 계자 전류 제어에 의해 일정하게 유지된다. 현재 대부분의 발전기 여자기의 여자전류제어를 위해 사용되는 AVR 시스템의 AC/DC 컨버터 부는 출력전압 제어가 가능한 위상제어 컨버터나 출력전압을 제어할 수 없는 다이오드 정류기와 DC/DC 컨버터를 결합하여 사용하고 있다. AC/DC 전력 변환장치로서 위상제어 컨버터나 출력전압을 제어할 수 없는 다이오드 정류기의 경우, AVR시스템의 전력을 공급하는 모선의 역률저하 및 저차 고조파 발생의 문제점을 야기 시키게 된다. 본 논문에서는 동기발전기의 여자전류 제어를 위해 사용되는 AVR 시스템 설계에 있어 단위역률 동작이 가능한 Boost형 AC/DC 컨버터와 모선의 부하변동에 속응성 있게 동작할 수 있는 전류 제어형 Buck 컨버터를 결합한 2단 3상 PWM AC/DC 컨버터에 대해 연구하였다. 제안된 AC/DC 컨버터를 시뮬레이션 한 결과 Boost 컨버터의 경우 단위 역률 동작 및 출력 DC 전압의 Boost 동작이 원할히 이루어졌으며, Buck 컨버터의 경우 다른 위상제어 컨버터에 비해 응답시간이 개선되었음을 알 수 있었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.169-173
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• 2005

In this paper, a comparative study of modified phase-angle, extinction-angle, and pulse width modulation control techniques for the purpose of power factor improvement of single-phase AC-AC voltage regulators have been illustrated as applied to a single-phase ac voltage converter by an example of the widely used single-phase induction motor as a dynamic load. Observations on power factor, displacement factor and total harmonic distortion factor are described and discussed on the basis of the simulated and measured results of this work.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 하계학술대회 논문집
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• pp.418-420
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• 1990

New asymmetrical PWM AC Chopper is proposed, which can improve the input power factor and can reduce harmonic contents at both its input and load sides. The switching scheme for the proposed technique is presented and the theoretical characteristics of AC voltage regulator controlled by APWM AC chopper are investigated through the digital simulation

• 전자공학회논문지S
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• 제35S권8호
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• pp.120-129
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• 1998

본 논문은 PWM(Pulse width Modulation)전압형 인버어터를 사용하여 전원차단 경우나 전압변동 및 부하변동에 의한 출력전류 변화에도 일정한 출력전압을 유지하는 무정전 전원장치에 대해 논하였다. 본 시스템은 전압형 인버어터를 교류전원과 동기시켜 운전하고 정상상태에서는 전원으로부터 운전하고 정상상태에서는 전원으로부터 직류측에 연결된 축전지를 태양전지를 이용한 광기전력효과와 함께 일정전압을 충전하며, 전원의 차단, 전원의 전압변동 및 부하전류의 변화에도 일정한 전압을 유지하도록 하였다. 출력은 PWM방식에 의하여 양호한 파형이 되도록 하고 전원차단과 부하의 상태의 변화 및 전원 전압 변동에도 일정한 전압으로 출력됨을 실험을 통하여 확인할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 A
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• pp.149-151
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• 2001

This paper proposes the design of STATCOM(static synchronous compensator) stabilizer for improving power system stability using fuzzy logic controller(FLC). The STATCOM DC voltage regulator contributes negative damping to the power system as the installation of STATCOM DC voltage regulator. STATCOM stabiliser is superimposed on the AC voltage regulator to compensate the negative damping effect. To evaluate usefulness of the proposed method, we perform the nonlinear simulation on a single-machine infinite bus system. As results of the simulations, the proposed method shows better control performance than PI controller in terms of damping effects.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2017년도 공동학술발표회
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• pp.221-221
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• 2017