• 대한전기학회:학술대회논문집
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• 대한전기학회 2009년도 제40회 하계학술대회
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• pp.905_906
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• 2009

본 논문은 한전 전력연구원이 주관하고 명지대학교와 (주)효성이 참여하는 연구과제의 결과물로써 다중펄스 컨버터와 PWM 컨버터로 구성된 20MVA급 Back-to-Back STATCOM의 시스템 구성 및 제어 동작특성에 대하여 정리하였다. 한전 전력연구원과 (주)효성이 국책과제를 통해 순수 국내기술로 개발한 10MVA급 다중펄스 STATCOM의 활용방안으로 10MVA급 PWM STATCOM 1기를 추가하여 두 STATCOM 각각의 DC link단을 연계시킨 20MVA급 Back-to-Back STATCOM을 구성하고 제어 알고리즘을 개발하였다. 또한 PSCAD/EMTDC 소프트웨어를 이용하여 개발한 Back-to-Back STATCOM의 제어 및 동작특성을 분석하였다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2010년도 하계학술대회 논문집
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• pp.387-388
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• 2010

본 논문은 수십 MW용량의 풍력단지를 교류전력망에 연계하기 위한 다중펄스 컨버터와 PWM 컨버터로 구성된 Back-to-Back 컨버터를 제안하였다. 시뮬레이션 모델개발과 하드웨어 축소모형 실험을 통해 제안하는 Back-to-Back 컨버터의 시스템 구성 및 동작특성에 대해서 분석하고 3-레벨 24-펄스 컨버터를 영전압과 점호각을 제어할 경우와 점호각만을 제어할 경우 제어상의 장 단점과 제어성능을 비교분석하였다.

• 전력전자학회논문지
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• 제15권6호
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• pp.451-459
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• 2010

본 논문은 대규모 풍력단지를 교류 전력망에 연계하기 위한 3-레벨 PWM 컨버터와 3-레벨 24-펄스 컨버터로 구성된 하이브리드 Back-to-Back 컨버터의 성능을 비교한 결과에 대해 기술하고 있다. 또한 3-레벨 24-펄스 컨버터를 점호각만 제어하는 경우와 영 전압제어를 같이 수행하는 경우 각각이 제어와 고조파레벨에 미치는 영향을 비교 분석하였다. 구체적인 성능비교를 위해 먼저 PSCAD/EMTDC 소프트웨어를 사용하여 시뮬레이션을 실시하고 이를 바탕으로 2 kVA 용량의 하드웨어 축소모형을 제작하고 실험을 실시하였다. 시뮬레이션과 실험을 통해 영전압과 점호각을 동시에 조절하는 방식과 점호각만 제어하는 방식의 성능비교분석을 하였다.

• 전력전자학회논문지
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• 제9권4호
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• pp.397-404
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• 2004

본 논문에서는 농형유도발전기를 이용한 계통연계형 풍력발전시스템의 가변속제어 기법이 제안된다. 농형유도발 전기는 간접벡터제어 방식으로 동작되는데 d-축 전류에 의해 여자가 제어되고 q-축 전류에 토크가 제어된다. 이 토크제어에 의해 발전기는 풍속의 변화에 대해서 항상 최대전력을 발생하도록 가변속 제어된다. 발전된 전력은 back-to-back PWM 컨버터에 의해 계통으로 공급된다. 계통측 컨버터는 q-축 전류 제어에 의해 직류링크 전압을 제어하고 d-축 전류 제어에 의해 계통측 역률을 제어할 수 있다. 제안된 기법은 M-G세트로 구성된 터빈시뮬레이터를 이용하여 실험적으로 검증된다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제15권3호
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• pp.200-207
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• 2015

This paper proposes an active damping control method for a grid-side converter that has an LCL grid filter in the back-to-back converter. To remove the resonant frequency components produced by the LCL filter, it is necessary to measure the grid current. To do this, sensors must be added. However, it is not necessary to add sensors because the grid current is estimated by designing a suboptimal observer. In order to remove the nonlinearity and to gain fast response of control, both feedback linearization and sliding mode control are applied. The proposed method is verified through a simulation.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2005년도 춘계학술대회
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• pp.51-54
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• 2005

Generator efficiency optimization is important for economic saving and environmental pollution reduction. In general, the machine loss can be reduced by the decreasing the flux level, resulting in the significant reduction of the core loss. This paper proposesan model-based controller is used to decrement the excitation current component on the basis of measured stator current and machine parameters and the q-axis current component controls the generator torque, by which the speed of the induction generator iscontrolled according to the variation of the wind speed in order to produce the maximum output power. The generator reference speed is adjusted according to the optimum tip-speed ratio. The generated power flows into the utility grid through the back-to-back PWM converter. The grid-side converter controls the dc link voltage and the line-side power factor by the q-axis and the d-axis current control, respectively. Experimental results are shown to verify the validity of the proposed scheme.

• 전기학회논문지
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• 제58권8호
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• pp.1544-1550
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• 2009

In this paper, a new single phase voltage sag/swell compensator using direct power conversion is proposed. A new compensator consists of input/output filter, series transformer and direct ac-ac converter, which is a single-phase back-to-back PWM converter without dc-link capacitors. Advantages of the proposed compensator include: simple power circuit by eliminating dc link electrolytic capacitors and thereby, improved reliability and increased life time of the entire compensator; simple PWM strategy or compensating voltage sag/swell at the same time and reduced switching losses in the ac-ac converter. Further, the proposed scheme is able to adopt simple switch commutation method without requiring complex four-step commutation method that is commonly employed in the direct power conversion. Simulation and experimental results are shown to demonstrate the advantages of the new compensator and PWM strategy. A 220V, 3kVA single-phase compensator based on the digital signal processor controller is built and tested.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.216-222
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• 2003

Today we have excellent motor drive system using high frequency carrier PWM control voltage source inverter in the other hand, we have met serious problems caused by high frequency switching. PWM Cyclo-converter called Matrix converter is expected as the new strategy Possible to improve these problems and add some more convenient features suitable for new drive system. in this Paper, we will introduce the background, features and outline of this converter, and additionally introduce some remarkable activity on this converter

• Journal of Power Electronics
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• 제18권2호
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• pp.604-614
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• 2018

This paper proposes a synchronous switching technique for a Vienna rectifier that uses carrier-based pulse width modulation (CB-PWM). A three-phase Vienna rectifier, similar to a three-level T-type converter with three back-to-back switches, is used as a PWM rectifier. Conventional CB-PWM requires six independent gate signals to operate back-to-back switches. When internal switches are operated synchronously, only three independent gate signals are required, which simplifies the construction of gate driver circuits. However, with this method, total harmonic distortion of the input current is higher than that with conventional CB-PWM switching. A reactive current injection technique is proposed to improve current distortion. The performance of the proposed synchronous switching method and the effectiveness of the reactive current injection technique are verified using simulations and experiments performed with a set of Vienna rectifiers rated at 5 kW.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.267-269
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• 2006

In this paper, a new single phase voltage sag/swell compensator using direct power conversion is introduced. A new compensator consists of input/output filter, series transformer and direct ac-ac converter, which is a single-phase back-to-back PWM converter without dc-link capacitors. Advantages of the proposed compensator include: simple power circuit by eliminating dc-link electrolytic capacitors and thereby, improved reliability and increased life time of the entire compensator; simple PWM strategy to compensate voltage sag/swell at the same time and reduced switching losses in the ac-ac converter. Further, the proposed scheme is able to adopt simple switch commutation method without requiring complex four-step commutation method commonly required in the direct power conversion. Simulation results are shown to demonstrate the advantages of the new compensator and PWM strategy.