• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.443-445
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• 1995

Since the residential load is an AC load, while the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell and must provide the sinusoidal wave current and voltage with unity power factor in the case of driving to Interact with utility line. It is always necessary for the output of solar cell to operate in the vicinity of maximum power point, since it is greatly fluctuated by insolation. This paper treats that we will constitute a single phase PWM voltage source inverter and trace the modulation index which always maximize the output of solar cell in propotion to insolation variation and prove it by simulation that we can provide current wave, which is nearly sinusoidal wave with unity power factor, for load and utility line.

• 한국정보통신학회논문지
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• 제10권4호
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• pp.652-658
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• 2006

본 논문은 승압형 컨버터, 강압형 컨버터 및 저주파 인버터를 이용한 고휘도 Short-Arc 램프용 전자식 안정기의 설계 및 제작에 관하여 기술하였다. 제안한 안정기는 130 [Hz]의 구형 저주파를 램프에 인가함으로써 고압 방전 램프에서 발생할 수 있는 음향공명현상을 제거하였으며, 25 [kHz]의 고주파 전압을 중첩시켜 아크튜브의 전극에서 발생할 수 있는 열적 불균형을 해소하였다. 또한 전압 전류의 합을 이용한 정전력 제어를 수행하여, 주위 환경 및 램프의 노화에 따른 램프 전압의 변화에 대하여 안정한 점등상태를 유지하였다. 실험 결과로부터, 제작한 전자식 안정기의 램프 전압, 전류 및 전력은 각각 123.8 [V], 8.1 [A] 1,002 [W]로 측정되었다.

• Journal of Power Electronics
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• 제8권3호
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• pp.259-267
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• 2008

Power quality improvement in a three-phase four-wire system is achieved using a new topology of DSTATCOM (distribution static compensator) consisting of a star/delta transformer with a tertiary winding and a three-leg VSC (voltage source converter). This new topology of DSTATCOM is proposed for power factor correction or voltage regulation along with harmonic elimination, load balancing and neutral current compensation. A tertiary winding is introduced in each phase for a delta connected secondary in addition to the star-star windings and this delta connected winding is responsible for neutral current compensation. The dynamic performance of the proposed DSTATCOM system is demonstrated using MATLAB with its Simulink and Power System Blockset (PSB) toolboxes under varying loads. The capacitor supported DC bus of the DSTATCOM is regulated to the reference voltage under varying loads.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2017년도 추계학술대회
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• pp.51-52
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• 2017

This paper presents an advanced DC droop using both an output current and a grid current. To control parallel-connected converters without communication, the DC droop control is conventionally used. The conventional DC droop control method droops output voltage using an output current. It cannot control the source current causing output voltage errors. This paper proposed the DC droop method using both an output current and a grid current to improve dynamic response of voltage droops. The simulation results with PSIM is provided.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1158-1160
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• 1999

This paper proposes a SSSC(Static Synchronous Series Compensator) power flow model to be incorporated into power flow calculation for the steady state analysis of the power system. SSSC provides controllable compensating voltage, which is in quadrature with the line current, over an capacitive and an inductive range, independently of the magnitude of the line current. This SSSC model is obtained from the injection model for series connected VSC(Voltage Source Converter) by adding a constraint that the injected voltage should be in quadrature with the line current. In this paper the static model is implemented into the continuation power-flow (CPF) program. It is shown that SSSC has its intrinsic superiority over TCSC in controllable power flow range.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.852-857
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• 2007

For electric traction using a large power converter, harmonic problem in the p-ower quality and regenerating energy in side of efficiency are important. Recently, by advance in power electronics technology, some countries are considering regenerative inverter from the points of view. when the electric tractions are stopped or driven through the falling slope way, it is very useful to supply surplus energy to the power source by regenerating system in the efficient side of energy and it is very economical. these regenerating energy are supported electrical equipment through DC line. In this research, the purposes are suppressing extra DC-line voltage and saving energy generated while electric traction is been driving on the falling slope way or reducing speed for railway using a 1500V DC-voltage. Besides, the accompanied defects of current distortion, low power factor and the voltage unbalance will be solved by developing the algorism of inverter having ability to compensate current harmonic.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.171-174
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• 2008

본 논문에서는 2단 인버터를 사용한 고성능 연계형 인버터의 구성을 제안하였다. 2단 인버터에서 하나의 인버터는 연계전압과 동일한 전압을 생성하고, 다른 하나의 인버터는 연계 전압에 포함되어 있는 고조파 성분을 제거하기 위한 전압을 생성한다. 본 논문의 제안된 구조는 PSIM 시뮬레이션으로 통해 확인하였으며, 그 결과 기본파(60Hz) 전압만 남게 되어 양질의 정현적인 전류를 연계 할 수 있음을 보였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.242-243
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• 2010

This paper investigates a power supply of medium voltage with enhanced ignition characteristics for plasma torch. Series resonant half-bridge topology is presented to be a suitable ignition circuitry. The ignition circuitry is integrated into the main power conversion system of a multi-phase staggered three-level dc-dc converter with a diode front-end rectifier. The plasma torch rated for 3MW, 2kA and having the physical size of 1m long is selected to be a high enthalpy source in waste disposal system. The steady-state and transient operations of plasma torch are simulated. The parameters of Cassie-Mary arc model are calculated based on 3D magneto-hydrodynamic simulations. Circuit simulation waveform shows that the ripple of arc current can be maintained within ${\pm}10%$ of its rated value under the existence of load disturbance. This power conversion configuration provides high enough ignition voltage around 5KA during ignition phase and high arc stability under the existence of arc disturbance noise resulting in a high-performance plasma torch system.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.271-273
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• 2002

Switching power supply are widely used in many industrial field. Power factor correction(PFC) has become an increasingly necessary feature in new power supply designs. The power factor correction circuit using boost converter used in input of power source is studied in this paper. In a boost power factor correction circuit there are two feedback control loops, which are a current feedback loop and a voltage feedback loop. In this paper, it is analyzed regulation performance of output voltage and compensator to improve of transient response that presented at continuous conduction mode(CCM) of boost PFC circuit. The validity of designed boost PFC circuit is confirmed by simulation and experimental results.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.307-310
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• 2008

This paper is proposed the vector control of 3-phase induction motor drive system by photovoltaic generation. For performance of vector control using a current control voltage source inverter(CC-VSI). CC-VSI is controlled by torque and flux producing component of motor current, relating with current and voltage value of photovoltaic arrays at maximum power point that varies follow different level of insolation. The MPPT using a DC-DC converter controlled the duty cycle to track maximum power from PV under different insolation conditions. The simulation results are shown that the characteristics and performance of drive system, which varies as each conditions of light by expresses in voltage($V_{dq}$), current($I_{dq}$), speed of motor and torque.