• 공학교육연구
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• 제19권2호
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• pp.83-90
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• 2016

Today, the world economy is changing rapidly thanks to the rapid progress of glottalization and the development of technology. It is important to analyze and offer specialized start-ups effect factors for collegians in order to systematically and successfully support technology-centered start-ups of collegians. Through which Entrepreneurship and job creation in developed countries. This study explores the current status and characteristics of Entrepreneurship education in Korea and suggests some directions for effective management of Entrepreneurship education.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(5)
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• pp.233-236
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• 2001

In this paper, a robust controller for UPS inverter is designed using CDM (Coefficient Diagram Method) developed by S. Manabe, by which a low order controller guaranteeing the stability and robustness is easily designed. The proposed controller consists of two control loops, the inner current control loop and the outer voltage control loop. The robustness of the proposed controller is verified through the theoretic evolution and its simulation.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 B
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• pp.980-982
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• 2004

The aim of the paper is to introduce the high power UPS with unity input power factor and to analyze the its major magnetic components. Inductance and flux density of 3 phases boost reactor is obtained by finite element method and compared with its expermental result. Also, basic characteristic of inverter transformer is inverstigated.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2015년도 추계학술대회 논문집
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• pp.149-150
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• 2015

This paper presents narrowband voltage controller for large capacity UPS system with low switching frequency. The proposed controller is repetitive controller applicable to low sampling. The controller reduces the control error for nonlinear load and improve efficiency. The proposed controller is verified through the experiment using 40kW UPS inverter.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제50권7호
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• pp.347-355
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• 2001

The conventional output filter design methods of a voltage source inverter includes two main problems: the performance is not sure to satisfy the specification under the nonlinear load; the designed filter must be occasionally modified when the controller is designed. In this paper, we analyze the relation between both linear and nonlinear loads, the output voltage magnitude, LC lowpass filter parameters, and the control response time. Upon the basis, both filter and controller are simultaneously designed for the performance to satisfy the specification under the nonlinear load as well as linear load. The proposed method sharply enhances the reliability of the performance. P.U is used for the method to be applied to all the quantities of the system. The simulation and the experiment of the proposed method carried out respectively to verify the validity.

• 전력전자학회논문지
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• 제16권6호
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• pp.561-568
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• 2011

본 논문은 단상 이중변환 무정전전원장치를 위한 단일 스위치 배전압 방식의 단상 PFC 컨버터의 동작 특성을 기술한다. 단일 스위치 배전압 방식의 단상 PFC 컨버터는 브릿지 다이오드와 양방향 능동 스위치 한 개만이 필요하며 재료비 절감이 가능하다. 하지만 이 회로가 제안된 후 동작 특성 및 제어기 설계에 대한 연구결과가 알려지지 않았다. 본 논문에서는 동작 특성과 제어기 설계방법을 기술하고 성능평가를 위해 단상 정격 3kVA 이중변환 무정전전원장치를 대상으로 실험을 수행하였다. 또한 실험을 통해 입력전류 제어, 입력역률 보상 성능을 확인하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1985년도 하계학술회의논문집
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• pp.271-272
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• 1985

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.14-19
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• 2004

This paper presents two approaches for designing a digital controller of UPS inverter with time response requirements and a fixed sampling time, which are inward and outward approaches based on a double loop feedback structure. In both approaches, the emulation method. is occupied. Thus we first design continuous-time controllers and then obtain digital controllers by using discretization. We apply the characteristic ratio assignment (CRA) in order to achieve the time response specifications. Also, the internal model control has been used for compensating phase delay in outward approach. The performances of the proposed controller are evaluated through several simulations carried out with Simpower system toolbox 3.0 of $Simulink^{(R)}$.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2007년도 춘계학술대회 논문집
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• pp.280-285
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• 2007

This study described the designed and construction of uninterruptible power supply(UPS) system for large scale computer system KISTI's supercomputer system is serviced 24 hours and power supply should be achieved in stable voltage and frequency range. We analyzed the electric power usage for 4 years, and we found several optimal parameters for new design of UPS configuration.

• 전력전자학회논문지
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• 제18권3호
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• pp.240-246
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• 2013

An Uninterruptible Power Supply(UPS) is a system designed to deliver energy during accidents that the AC mains is out of its acceptable limits, without interruption of power flow through the load. Battery Discharger is the device to supply high quality power to the Inverter, when accidents occur, such as Power Failure. The Battery Discharger should have a fast response characteristics. The LLC resonant converter for UPS battery discharger is proposed. The proposed Battery Discharger offers substantial improvements in efficiency, size and cost. The proposed Battery Discharger of UPS approach is a good solution for high power applications above KW. To verify the validity of proposed Battery Discharger, simulations and experiments are carried out.