• 전기학회논문지
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• 제56권4호
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• pp.705-715
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• 2007

Recently, the interest on power quality has been hot issue because the equipments cause voltage disturbance and have become more sensitive to the voltage disturbance. Additionally, the reseach on power electronic equipments applying to the high power has been increased. This paper deals with Line-Interactive Dynamic Voltage Restorer(LIDVR) system using 7-Level H-Bridge inverter, which is one of the solutions to compensate the voltage disturbance and to increase the power of equipments. The LIDVR has the following advantages comparing to the DVR with the series injection transformer. It has the power factor near to unity under the condition of normal source voltage, can compensate the harmonic current of the load and the instant interruption, and has the fast response. First, the construction, the operation mode and algebraic modeling of LIDVR are reviewed. And then the voltage control algorithm is proposed to get the sinusoidal load voltage with constant amplitude. Finally, simulation and experiment results verify the proposed LIDVR system.

• Journal of Power Electronics
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• 제4권3호
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• pp.180-187
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• 2004

This paper proposes a new control strategy for the dynamic voltage restorer (DVR). It is based on a synchronous PI decoupling control strategy which features fast response time and low steady state error. Therefore, the proposed control strategy produces faster action time against voltage sag and guarantees more than enough compensation for reduced supply voltage. Experimental results, implemented with the TMS320C3${\times}$DSP control unit, are shown to validate the effectiveness of the proposed control strategy.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제51권4호
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• pp.203-209
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• 2002

This paper presents a new control scheme for a DVR(Dynamic Voltage Restorer) system consisting of series voltage source PWM converters. To control negative sequence component of source voltage the detection of negative sequence is necessary. Generally, filtering process is used tn do that. Through this filtering process has some problems. This paper suggests a new method of separating positive and negative sequences. This control system is designed using differential controllers and digital filters, and positive sequence and negative sequences are controlled respectively. The performance of the presented controller and scheme are confirmed through simulation and actual experiment by 2.5kVA prototype DVR.

• 조명전기설비학회논문지
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• 제26권11호
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• pp.54-61
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• 2012

This study investigated the relationship between the response time of DVR (Dynamic Voltage Restorer) and the possible compensation range for voltage dips by the DVR system which protects the 3-phase phase-controlled rectifier from said dips. As a result, the permissible range of voltage dip is presented in a 3-phase phase-controlled rectifier. When the DVR compensates for voltage dip, the range of voltage dip can be compensated according to the DVR's response time. Using the proposed method, DVR response time can be determined from the parameters of the 3-phase phase-controlled rectifier and the possible compensatory range of voltage dip, while at the same time it is possible to use a control system having an appropriate speed. Therefore, the use of excessively fast equipment can be avoided, improving the stability of the overall system. The reliability of the DVR concerning the 3-phase phase-controlled rectifier can be verified by simulation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(2)
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• pp.554-559
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• 2003

A new control strategy for dynamic voltage restorer (DVR) is proposed. It is based on synchronous PI control strategy which features fast response. Therefore, the proposed control strategy takes faster action against a voltage sag. Experimental results, executed by DSP, are shown to validate the proposed control strategy.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2008년도 하계학술대회 논문집
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• pp.69-71
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• 2008

Recently, the interest on power quality has been hot issue because the equipments cause voltage disturbance and become more sensitive to the voltage disturbance. The DVR(Dynamic Voltage Restorer) is one of the Custom Power Device that can compensate the voltage. DVR operates as a series connected compensator whose output voltage can be controlled system voltage. And the magnitude of compensation voltage is limited by the characteristics of system and load. Compensation capability of DVR was simulated by EMTDC under several condition. This paper analyzed effect of DVR's compensation at power quality test center which has SSFG(Sag, swell, and Flicker Generator, CPDs(SSTS, DVR, DSTATCOM), and loads.

• 전력전자학회논문지
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• 제8권5호
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• pp.435-441
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• 2003

순시전압강하보상기 (DVR)는 순시전압강하 및 상승을 보상하기 위한 가장 효과적이고 경제적인 수단으로 알려져 있다. 본 논문은 계통의 전압이 사고에 의해서 심하게 왜곡되는 경우에서도 계통과 동기된 정현적인 기준파를 생성하는 방법을 제시한다. 제안된 기준파발생기 (RWG)는 사고로 왜곡된 전압으로부터 원래의 정현적인 파형을 추출하고 정상 성분만의 전압을 합성하여 DVR의 제어에 사용하도록 한다. 전윈 전압의 사고 순간에도 RWG는 과도적인 문제가 없는 안정된 정현 파형을 출력한다.

• 조명전기설비학회논문지
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• 제24권9호
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• pp.165-171
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• 2010

There are many researches on Power Quality Device to protect the critical load and power system as the nonlinear load and precision load are adopted into the power system recently. To analyze the voltage compensation of voltage sag and voltage swell by DVR, which is connected to the important load in series, this paper shows PSCAD/EMTDC simulation and its verification by comparing with the actual DVR output of 2MVA. DVR control scheme in this paper is applicable to compensate single-phase, 2-phases or 3-phases voltage sag as well as DVR for distribution system.

• 전기학회논문지
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• 제61권2호
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• pp.199-208
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• 2012

This paper proposes a quasi Z-source DVR(Dynamic Voltage Restorer) system with a series connection of the output terminals, to compensate the voltage variations in the 6.6[kV]/60[Hz] power distribution system. The conventional DVR using one quasi Z-source AC-AC converter has the advantage which it can compensate the voltage variations without the need for the additional energy storage device such as a battery, but it is impossible to compensate for the 50[%] under voltage sags. To solve this problem, a DVR system using two quasi Z-source AC-AC converters with the series connection of the output terminals is proposed. By controlling the duty ratio D in the buck-boost mode, the proposed system can control the compensation voltage. For case verification of the proposed system, PSIM simulation is achieved. As a result, in case that the voltage sags-swells occur 10[%], 20[%], 60[%] in power distribution system, and, in case that the 50[%] under voltage sags-swells continuously occur, all case could compensate by the proposed system. Especially, the compensated voltage THD was examined under the condition of the 10[%]~50[%] voltage sags and the 20[${\Omega}$]~100[${\Omega}$] load changes. The compensated voltage THD was worse for the higher load resistances and more severe voltage sags. Finally, In case of the voltage swells compensation, the compensation factor has approached nearly 1 regardless of the load resistance changes, while the compensation factor of voltage sags was related to the load variations.

• 한국항행학회논문지
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• 제19권5호
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• pp.433-439
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• 2015

최근 컴퓨터, 전기, 전자, 통신, 반도체 장비 등의 전기적 외란에 민감한 부하 설비의 사용이 증가함에 따라 전력 품질에 대한 관심이 높아지고 있다. 더 나아가서는 정밀 부하 장비들에 가장 빈번하게 발생하는 순간 전압 강하는 전력 품질 향상을 위해 적정한 보상이 필요하게 된다. 이를 위해 전기 이중층 커패시터 (EDLC : electric double layer capacitor)를 사용한 순간전압강하 보상장치가 개발되어 적용되고 있다. 본 논문에서는 순간전압강하 보상장치 (DVR : dynamic voltage restorer)에 사용되는 전기 이중층 커패시터(EDLC)에 비해 동일 사이즈 대비 에너지 밀도가 높은 하이브리드 커패시터 (hybrid capacitor)를 적용하는 연구를 하였고, 또한, 유도등의 비상 전원으로써 10년 이상의 수명을 보증할 수 있는 제품으로 하이브리드 커패시터 (hybrid capacitor)의 적용 가능성을 확인하였다.