3상 멀티레벨 인버터를 이용한 정지형 무효전력보상기의 해석

최남섭 여수대학교 2002 論文集 Vol.17 No.-

In this paper, a static Var compensator using three-phase multilevel inverter is presented. A general and simple model for the overall system is obtained using circuit DQ transformation. DC and AC analyses are achieved to characterize the open-loop system. Finally, predicted results are verified by comparing the modeling one with the simulation results

회로 DQ 변환을 이용한 하이브리드 Cascade 5-레벨 PWM 인버터를 포함하는 무효전력보상기의 모델링

최남섭 한국정보통신학회 2002 한국정보통신학회논문지 Vol.6 No.3

Hybrid cascade multilevel PWM inverter has advantages of hybrid structure which enhances the better utilization of power semiconductor switches, that is, both hi호 power-low frequency switch, GTO and low power-high frequency switch, IGBT can be used in the same circuit. In this paper, a static var compensator using hybrid cascade 5-level PWM inverter is presented for high voltage/high power applications. The proposed system is modelled by circuit DQ transformation, and thus an equivalent circuit is obtained which reveals the important characteristics of the system and lead to the related equations. Finally, circuit structure and characteristics is presented and the validity of the characteristics analysis is shown through PSIM simulation.

브리지형 멀티레벨 정류기의 회로 DQ 모델링 및 해석

최남섭 여수대학교 1999 論文集 Vol.14 No.2

This paper presents the circuit DQ modeling and analysis for bridge-type multilevel rectifier. Recently, a bridge-type multilevel inverter has been proposed and proven to be useful for high voltage, high power applications. However, the analysis for the characteristics has not been presented yet. This paper deals with the following topics; system description, circuit DQ modelling, analytic equations for the control and finally simulation results. The simulationl results show good agreements between exact model circuit DQ transformed model.

출력전압 피드백을 갖는 AC 초퍼를 사용한 전압 위상천이기의 특성에 대한 연구

최남섭 여수대학교 2001 論文集 Vol.16 No.-

This paper propose a three-phase phase shifter using PWM AC/AC converter with output voltage feedback, which can improve system response and control stability in the applications. Phase shifter has been used as a means of power-flow control and for transient stability improvement in AC transmission system. Until now, phase shifters have been based on an injection transformer. Conventional phase shifters with tap changers require regular maintenance and allow only step-like control of the phase angle. This paper deals with the circuit topology, operating principle so that the features of the phase shifter will be shown through computer simulation, especially using PSIM software.

회로 DQ 변환을 이용한 3상 PWM 정류기의 동작특성 해석

최남섭 여수대학교 산업기술지역개발연구소 2000 産業基術硏究所 論文集 Vol.9 No.-

The recently proposed circuit DQ transformation is used to analyze a three phase voltage source pulse-width modulation(PWM) rectifier. DC operating point and some properties of the PWM rectifier are completely determined. Most features of the converter are clearly interpreted. They are as follows: (1) the output voltage can be controlled from zero to maximum, (2) the system is equivalently an ideal current source in steady state, (3) the system can be described as linear circuits and (4) the input power factor can be arbitrarily controlled within a certain control range. The result can be used as a design guide for the PWM rectifier.

PWM Cuk AC-AC 컨버터를 위한 새로운 Commutation 회로

최남섭,김인동,Li Yulong,노의철 전력전자학회 2006 전력전자학회 논문지 Vol.11 No.5

This paper proposes a new commutation circuit for a PWM Cuk AC-AC converter. The proposed commutation circuit utilizes a modified Undeland snubber as a commutation aid. The snubber circuit has some good features such as reduction of voltage/current stress of the main switches and improved efficiency. The experiment results show the adaptability and feasibility of the proposed commutation circuit. 본 논문에서는 PWM Cuk AC-AC 컨버터를 위한 새로운 commutation 회로를 제안한다. 제안된 commutation 회로는 컨버터 전류의 commutation을 위하여 개선된 Undeland 스너버를 이용한다. 개선된 스너버 회로는 주 스위치의 전압/전류 스트레스 저감, 효율 개선과 같은 장점을 갖는다. 본 논문에서는 실험을 통하여 제안된 commutation 회로의 효과와 적용 가능성을 확인하였다.

Bacteroides intermedius의 항원 이종성과 조직독성과의 관계에 관한 연구

최남섭,정종평,손성희 서울大學校 齒科大學 1989 齒大 論文集 Vol.13 No.2

전압조절이 가능한 단상변압기 응용을 위한 PWM Buck-Boost AC/AC 컨버터

최남섭,강정식 여수대학교 산업기술지역개발연구소 2001 産業基術硏究所 論文集 Vol.10 No.-

Computers and automated manufacturing processes are very susceptible to voltage sags, surges and outages. The need for greater power reliability makes the end-users to use the uninterrupted power supply and other electronic power conditioning means to maintain the stable voltage. In this paper, a single-phase buck-boost ac-ac converter for single-phase transformer with voltage regulation for Custom Power Application is presented. The presented converter uses IGBT's as switching module and maintains the stable voltage through PWM technology in spite of the input voltage sags, surges and load rejections. In this paper, the operation characteristics and schematics of the power converter are illustrated using PSPICE simulations.

정전압 출력 특성을 갖는 다기능 3상 전자식 강압형 변압기

최남섭 한국정보통신학회 2001 한국정보통신학회논문지 Vol.5 No.2

본 논문에서는 Custom Power 응용을 위한 전압 안정화 특성을 갖는 다기능 3상 전자식 강압형 변압기가 제안된다. 제안된 전자식 변압기는 다음과 같은 특징을 갖는다. 1) 무게가 1㎾ 기준 일반 변압기의 40% 수준이다. 2) PWM 제어에 의하여 입력전압의 변동에 무관한 출력전압을 유지하는 전압 안정화 기능을 갖는다 3) 전원 또는 부하단의 Emergency에 대하여 회로 차단기의 기능도 갖는다. 4) 부하에 최초 전원 공급시, 낮은 전압으로부터 점진적으로 증가시켜가면서 전원을 인가하여, 전원 투입시 발생할 수 있는 돌입전류나 과도 충격을 제거할 수 있다. 그 밖에 무부하시 전원차단 기능과, 왜곡된 입력전압에 대한 보상기능을 추가 할 수 있다. 본 논문에서는 제안된 강압형 전자식 변압기의 회로 구성과 특징을 설명하고, 이를 PSPICE 시뮬레이션을 통하여 동작특성을 보인다. In this paper, a multifunctional three-phase electronic step-down transformer with output voltage stabilization characteristics is presented for custom power applications. The proposed electronic transformer has some advantages and features as follows: 1) It has 40 % weights lighter than that of commercial magnetic transformer, 2) It has output voltage stabilization characteristic with regulated output voltage over input variations, 3) It cab be operated as circuit breaker in the case of emergency, 4) It can be operated with so called soft starting function. Moreover, the electronic transformer may have stand-by power cutoff function and act as distortion compensator. This paper show the circuit diagram and present its features through various PSPICE simulations.

3상 PWM AC/AC Buck 컨버터를 사용한 3상 전압 위상천이기

최남섭 한국정보통신학회 2001 한국정보통신학회논문지 Vol.5 No.6

전력의 흐름제어와 전원시스템의 과도안정성 개선을 위하여 전압의 위상을 제어할 필요성이 있는 경우가 있다. 이제까지 위상 천이기는 주로 상변압기와 사이리스터 탭변환기를 사용하여 구성하였는데, 이는 응답속응성이 느리고 제어안정성이 떨어지는 단점이 있다. 본 논문에서는 PWM AC/AC 컨버터를 사용한 3상 전압 위상천이기를 제안한다. 제안된 3상 전압 위상천이기는 PWM제어에 의하여 응답속응성이 우수하고 과도상태에서의 제어안정성을 개선시킬 수 있는 장점이 있다. 본 논문에서는 제안된 시스템의 회로구성, 동작원리와 특성 등을 설명하여 그 특징과 장단점을 나타내고, 이를 PSIM 컴퓨터 시뮬레이션을 통하여 동작과 해석의 타당성을 확인한다. Phase shifter has been used as a means of power-flow control and for transient stability improvement in AC transmission system. Until now, phase shifters have been based on an injection transformer. Conventional phase shifters with tap changers require regular maintenance and allow only step-like control of the phase angle. This paper propose a three-phase phase shifter using PWM AC/AC converter, which can improve system response and control stability in the applications. This paper deals with the circuit topology, operating principle so that the features of the phase shifter will be shown through computer simulation, especially using PSIM software.