• 대한전기학회:학술대회논문집
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• 대한전기학회 1990년도 추계학술대회 논문집 학회본부
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• pp.283-286
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• 1990

This paper presents a PWM controlled cycloconverter with a LC resonant circuit for induction heating. This cycloconverter converts commercial frequency power to high frequency power directly. So conversion efficiency improved. Controlling a input reactive power regardless of load power, it has sinusoidal input current waveforms as well as a input displacement factor at 1.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1988년도 추계학술대회 논문집 학회본부
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• pp.277-280
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• 1988

In the current-controlled PWM, the actual current tracks the sinusoidal reference wave within desired hyeteresis band. This paper au99e61s the current control scheme for voltage-fed single-phase inverter and presents the simulation results. It is expected that the inverter with this control method produces no significant lower-order harmonics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.1029-1031
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• 2001

In this paper, we propose a three-phase soft-switching PWM-PFC converter and describe the circuit operations and the experimental results. The proposed converter is constructed by using a resonant network in parallel with the main switch of the conventional PWM converter. A new PWM-PFC converter achieves including the auxiliary switches without increasing their voltage and current stress.

• 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.

• 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

• 전력전자학회:학술대회논문집
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• 전력전자학회 1998년도 전력전자학술대회 논문집
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• pp.287-290
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• 1998

This paper presents PWM method which modulates two third period only during one cycle of power converter. This method is compared with the conventionl sinusoidal modulation method applying to the power converter with large capacity necessitating low switching frequency. The presented modulation method enables to reduce power semiconductor rating, minimize switching loss, and improve the current wave form.

• 대한전기학회논문지
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• 제38권6호
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• pp.431-440
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• 1989

This paper proposes a new PWM cycloconverter which can step up input voltage. With input reactors ac power supply acts as current source, and with output capacitors the balanced output voltage is build-up. The converter is modeled with fourth order state equation using dq transformation and the steady state characteristics are evaluated. It is shown that the proposed converter can generate the output voltage 2-5 times greater than input voltage. The output voltage and input current have sinusoidal and smooth waveforms and the converter is capable of voltage build-up. The characteristics of the proposed converter is verified simulation and experiment.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 추계학술대회 논문집 학회본부
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• pp.370-372
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• 1996

A control scheme for the Voltage-sourced PWM converter based on space vector equations is introduced. The main advantages of this new control scheme are that sinusoidal line currents with nearly unity power factor, ripple-free DC voltage output are achevied without current sensors. The dynamical equations with battery model is derived. The proposed scheme is verified by computer simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 추계학술대회 논문집 학회본부 A
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• pp.398-402
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• 1999

In PWM inverter fed traction motor drive systems, the switching frequency is restricted and thus the electromagnetic acoustic noise is generated. To reduce such an audible noise, we propose the modified RSF(Randomized Switching Frequency)-PWM method. In the proposed RSF-PWM method, both triangular wave and sawtooth wave are used in one period as carrier waves. Because the proposed method has inherently the same property as sinusoidal PWM method, there is no problem of linearity. To verify the validity of the modified RSF-PWM method, computer simulations are carried out.

• 전력전자학회논문지
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• 제10권4호
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• pp.331-338
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• 2005

본 논문에서는 2상 유도전동기의 가변속장치인 2-레그 및 4-레그 2상 인버터의 PWM 방식을 제안하였다. 기존의 SVPWM방식을 2-레그 인버터에 적용하기가 복잡하나, 본 논문에서는 캐리어 삼각파 PWM방식으로 단순화시켰다. 4-레그 인버터의 경우 전압벡터가 16개가 되어 전형적인 공간전압벡터이론을 적용하기가 복잡하다. 따라서, 본 논문에서는 이를 대신하여 2-레그 인버터형 삼각파 PWM방식을 기본으로 하여 4-레그 인버터에 적용할 수 있는 삼각파 PWM파형으로 단순화하였다. 제안된 2상 PWM방식에 대한 타당성을 확인하기 위해 모의 실험과 실험이 실행되었다.