• 전력전자학회논문지
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• 제10권4호
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• pp.403-410
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• 2005

본 논문은 정지궤도 위성을 위한 완전조절방식을 갖는 태양전지 어레이 션트 전압조절기를 나타낸다. 스위칭 션트 전압조절기는 태양전지 어레이 전력을 조절하는 어레이 스위치 모듈들로 구성된다. 이러한 태양전지 어레이 션트 모듈들은 스위칭을 통해 버스에 태양전지 회로가 접속되거나 분리되며, 단지 FPGA 로직변경 만을 통해 이전의 회로설계로부터 간단하게 확장이 가능하다. 제안된 설계회로를 검증하기위해 제어로직 및 최악조건해석이 수행되었으며, 시뮬레이션 및 실험결과를 보여준다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.669-672
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• 2001

Generally, previous converter is divided into two categories to get high power factor and good output regulation. These two categories can be combined a category with a main switch. These converter is called Single Stage PFC Converter. This approach has good electrical characteristics of high power factor and fast output voltage regulation. The cost and size are important factor to design the converter in low power system. Even single stage can reduce the size and cost, but this approach needs to have additional circuit like control, PWM circuit. To improve these demerits, Top switch is one of good choice In reduce and size in low power single stage converter. Because it has the ability of current limit, thermal protection, oscillator, control circuit as well as a main switch ability.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2002년도 학술대회논문집
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• pp.369-374
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• 2002

This paper presented the development trend of UPS and SPS system has focused on large scale system and more convenient system to maintenance and management. In this paper, we proposed low price and high performance SPSs which can de voltage regulation, harmonic reduction, and capable capacity extension in power. These SPSs are composed by two SPSs in their functional structure, one is power control part including voltage regulation and instant voltage compensaton. The others part is web based monitoring and trend management part for more convenient to SPS operator.

• 전력전자학회:학술대회논문집
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• 전력전자학회 1999년도 전력전자학술대회 논문집
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• pp.333-337
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• 1999

This paper presents the DQ transfomation space space vector modulation method to devel control algorithm of distribu STATCON(STATic CONdenser) for line volt regulation, dc link voltage regulation harmonics compensation. The Performance an of a PI with ramp comparision and synchro reference frame current controller is carried Based on these analysis, the control perform are desirable to compensate the harmonics a regulate dc link and line voltage of Distrib line.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.183-185
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• 2006

This paper presents a SISO nonlinear controller for the power system consisting of a synchronous generator connected to an infinite bus. The proposed controller is based on input-output feedback linearization, with a modified version of the terminal voltage equation used as the output. The resulting closed-loop has no internal dynamics, and thus stability is guaranteed. The controller performance is seen to be effective through simulations.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 B
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• pp.725-727
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• 1998

It is difficult to determine the controller parameters that we can get optimum response of the controlled process variable. In this paper we investigate the effects of various elements of which a gas turbine MW control loop is consists. And we describe the result of actual adjustment on the parameters of these elements to improve the speed regulation of a gas turbine.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2019년도 전력전자학술대회
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• pp.467-468
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• 2019

This paper proposes an improved bus voltage regulation scheme in filter-based reference current generation of power management for DC home grid with photovoltaics (PV), battery, and ultracapacitor (ultracap) by using feedforward terms instead of the filter output to produce the ultracap reference current. Simulation results have proved the effectiveness of the proposed scheme.

• 전기학회논문지
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• 제65권4호
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• pp.533-538
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• 2016

In a power grid that has a high penetration of wind power, the highly-fluctuating output power of wind turbine generators (WTGs) adversely impacts the power quality in terms of the system frequency. This paper proposes a power smoothing scheme of a variable-speed WTG that can smooth its fluctuating output power caused by varying wind speeds, thereby improving system frequency regulation. To achieve this, an additional loop relying on the frequency deviation that operates in association with the maximum power point tracking control loop, is proposed; its control gain is modified with the rotor speed. For a low rotor speed, to ensure the stable operation of a WTG, the gain is set to be proportional to the square of the rotor speed. For a high rotor speed, to improve the power smoothing capability, the control gain is set to be proportional to the cube of the rotor speed. The performance of the proposed scheme is investigated under varying wind speeds for the IEEE 14-bus system using an EMTP-RV simulator. The simulation results indicate that the proposed scheme can mitigate the output power fluctuation of WTGs caused by varying wind speeds by adjusting the control gain depending on the rotor speed, thereby supporting system frequency regulation.

• 한국산학기술학회논문지
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• 제21권10호
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• pp.212-221
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• 2020

본 연구는 병원 간호사의 인지적 정서조절전략과 전문직 삶의 질의 정도를 확인하고 전문직 삶의 질에 영향을 미치는 요인을 알아보기 위해서 수행되었다. 연구 대상자는 서울 소재 일개 대학병원에서 근무하고 있는 일반 간호사 176명으로, 2020년 3월 3일에서 16일까지 구조화된 온라인 설문지를 통하여 자료수집 하였다. 자료 분석은 SPSS WIN version 25.0 프로그램을 이용하여 기술통계, t-test, ANOVA, Pearson's correlation coefficient, Multiple regression analysis 로 분석하였다. 연구 결과, 공감만족에 영향을 미치는 요인은 적응적 인지적 정서조절전략(β=.501, p<.001)이었고, 설명력은 24.8%였다. 소진에 영향을 미치는 요인은 적응적 인지적 정서조절전략(β=-.435, p<.001), 부적응적 인지적 정서조절전략(β=.427, p<.001), 학력(학사)(β=.188, p=.046)이었으며, 설명력은 36.8%였다. 대상자의 이차 외상성 스트레스에 영향을 미치는 요인으로는 부적응적 인지적 정서조절전략(β=.502, p<.001)이었으며, 설명력은 24.4%였다. 이상의 연구결과를 토대로 적응적 인지적 정서조절전략을 습득하고 부적응적 인지적 정서조절전략을 덜 사용하도록 하는데 초점을 맞추어 병원 간호사의 전문직 삶의 질 향상을 도모하기 위한 프로그램 개발이 필요하다.

• 동력기계공학회지
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• 제21권6호
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• pp.68-78
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• 2017

Major countries have tighten their NOx regulation of diesel passenger cars. In the case of the EU, the regulation has been toughen up to 6.25 times since 2000. Despite the regulation the NOx concentration of the ambient has not been reduced proportionally. Futhermore, some manufacturers were disclosed using a defeat device for meeting the regulation illegally. As these issues, to reduce NOx emission practically, Korea and the EU introduced the real-world driving emission(RDE) regulation and the test method that will be applied after 2017. Also, the US has used the test equipment(PEMS) to detect a defeat device. In this paper, for the regulation to make a soft landing in Korea, 4 diesel passenger cars which met Euro 6a~6b regulation and were equipped with LNT/SCR were tested at a chassis dynamometer with environmental chamber applying the off-cycles(FTP, US06, SC03, HWFET and CADC) and several ambient condition(-7 and $14^{\circ}C$) as well as certification mode(NEDC, WLTC@ $23^{\circ}C$). The result of the test showed that the ambient temp. and the engine load as a test mode impacted the NOx emission of the cars while the vehicles with SCR emitted NOx lower than with LNT. Additionally, to propose an effective RDE test method, the above result was compared with the results of the other papers which tested RDE using the same cars.