• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.19-21
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• 2006

This paper presents the control method that inverter output keeps to linear to reference voltage of Synchronous Reluctance Motor using DC Link voltage Synthesis. The Inverter output voltage cannot be displayed to linear about inverter reference voltage if Real DC Link voltage is different from DC Link voltage of PWM amplitude. Also, the overmodulation that there is linearity broken if reference voltage is out of range that inverter can output voltage. Torque ripple generates the vibration and noise of a motor. This paper proposes the control method so that torque ripple decreases and the linearity of inverter output keeps using the DC Link voltage Synthesis.

• 전력전자학회논문지
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• 제18권5호
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• pp.422-428
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• 2013

Recently, we use a static synchronous compensator(STATCOM) with cascaded H-bride topologies, because it is easy to increase capacity and to reduce total harmonic distortion(THD). When we use equipment for reactive power compensation, dc-link voltage unbalances occur from several reasons although loads are balanced. In the past, switching pattern change of single phase inverter and reference voltage magnitude change of inverter equipped with power sensor have been used for dc-link voltage balance. But previous methods are more complicated and expensive because of additional component costs. Therefore, this paper explains reasons of dc-link voltage unbalance and proposes solution. This solution is complex method that is composed of reference voltage magnitude change of inverter without additional hardware and shifted phase angle of inverter reference voltages change. It proves possibility through 1000[KVA] system simulation.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2004년도 춘계종합학술대회
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• pp.569-572
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• 2004

다수의 사람들이 관리ㆍ운영하는 많은 분량의 HTML 문서들로 이루어진 웹사이트들의 경우에는 현수참조(Dangling Reference)와 오문참조(Inaccurate Contents Reference)와 같은 깨진 링크(Broken Link)를 관리하는데 많은 어려움이 따른다. 즉, HTML 페이지의 내용 중 연결구조에 관련된 부분을 변경하거나 삭제하는 경우 문서들간의 연결구조에 대한 무결성(Integrity)을 보장하기가 어렵다. 본 논문에서는 Parent 페이지와 Child 페이지에서의 무결성 제약조건(Integrity Constraint Condition)들을 조사하여 정의하고, 확장 UML로 표현하는 방법에 대해 연구하였다.

• 조명전기설비학회논문지
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• 제27권7호
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• pp.59-66
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• 2013

This paper proposes a new voltage reference generation method for Four-Switch Inverters(FSI) with compensation of the neutral DC-link voltage variation. Since FSIs have the split DC-link causing the inherent problem of voltage fluctuations in the upper and lower capacitors, it is required to take account the voltage difference between the top and bottom capacitors. In this paper, to reduce the effect by the voltage variation, reference voltages are modified by adding compensation voltages proportional to the voltage difference between upper and lower capacitors. Simulation results showing control performance of induction and permanent magnet motors demonstrate the validity of the proposed method.

• 조명전기설비학회논문지
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• 제28권11호
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• pp.112-122
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• 2014

This paper proposes a PMSM torque control method considering DC-link voltage variation and friction torque. In general EV/HEV application, two dimensions look-up table(2D-LUT) is used for reference current generation due to its stable and robust torque control performance. Conventionally, this 2D-LUT is established by flux-torque table to overcome the DC-link voltage variation. However, the flux table establishment is more complex than the speed table establishment. Moreover, one flux data reflects several speed conditions in variable DC-link voltage, friction torque cannot be considered by using the flux table. In this paper, speed-torque 2D-LUT is used for current reference generation. With this table, PMSM torque control is well achieved regardless of DC-link voltage variation by the proposed control method. Simulation and experimental results validate improvement of torque control error through friction torque compensation.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1997년도 전력전자학술대회 논문집
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• pp.14-20
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• 1997

Due to several advantages of Pulse Width Modulated(PWM) Converter, such as unity power factor with low-harmonics and energy regeneration, PWM converter has been widely used in industrial application. In every application of energy conversion equipment, the design and implementation must be carried out considering performance and cost. High quality with low cost is the best choice for energy conversion equipment. High dc link voltage can reduce inverter and motor side losses and system dimension compare to low dc link voltage. Analog controller can make PWM converter cheaper without considerable degradation of the performance than digital controller. This paper shows the simplified analog controller-for 600V dc link voltage using stationary reference frame control and the simulation results.

• 전력전자학회논문지
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• 제17권1호
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• pp.8-13
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• 2012

DSTATCOM is active filter that reduces nonlinear and unbalanced currents. Researches about DSTATCOM are mainly divided two parts, one is the reference value calculation of compensation current depending on the calculation of the load-side average active power and dc-link capacitor average voltage, the other part is actual current control depending on the reference value of compensation current. This paper proposes a calculation of dc-link capacitor average voltage ripple voltage extraction instead of conventional method using LPF. The utility of the proposed algorithm is verified through the theoretical analysis and the experiment under unbalance loads and non-linear load.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2010년도 춘계학술발표대회
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• pp.860-861
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• 2010

본 논문에서는 논문들 간의 참조 정보를 이용한 새로운 논문 유사도 계산 방안을 제안한다. 본 논문에서 제안하는 방안은 in-link와 out-link를 undirected-link로 간주함으로써 in-link와 out-link를 동시에 이용하여 논문들 간의 유사도를 적절하게 계산한다. 사례 분석을 통해서 제안하는 방안의 우수성을 검증한다.

• Journal of Power Electronics
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• 제14권4호
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• pp.764-777
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• 2014

This study analyzes the mathematical relationship between DC-link voltage and system parameters for shunt active power filters (APFs). Analysis and mathematical deduction are used to determine the required minimum DC-link voltage for APF. A novel adaptive DC-link voltage controller for the three-phase four-wire shunt APF is then proposed. In this controller, the DC-link voltage reference value will be maintained at the required minimum voltage level. Therefore, power consumption and switching loss will effectively decrease. The DC-link voltage can also adaptively yield different DC-link voltage levels based on different harmonic currents and grid voltage levels and thus avoid the effects of harmonic current and grid voltage fluctuation on compensation performance. Finally, representative simulation and experimental results in a three-phase four-wire center-split shunt APF are presented to verify the validity and effectiveness of the minimum DC-link voltage design and the proposed adaptive DC-link voltage controller.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2002년도 춘계종합학술대회
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• pp.380-383
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• 2002

KLDP(리눅스 한글 문서 프로젝트, http://kldp.org)와 같이 많은 분량의 HTML 문서들로 이루어진 매뉴얼 사이트를 관리하는데 가장 어려운 점은 현수 참조(dangling reference), 오문 참조 (inaccurate content reference)와 같은 깨진 링크(broken link)를 관리하는 것이다. 본 논문에서는 웹사이트의 HTML 문서들 사이에 존재하는 관계성(Relationship)과 제약 조건(Constraints)을 정의하여, HTML 문서의 삽입, 삭제, 변경이 발생할 경우 사용자에게 통지하거나, 트리거를 수행하여 HTML 문서들의 무결성(Integrity)을 유지할 수 있도록 하는 HIMS(HTML Document Integrity Management System)시스템을 설계 및 구현하였다.