• 한국전자통신학회논문지
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• 제10권1호
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• pp.111-116
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• 2015

본 연구에서는 실내조명을 위한 LED 조명용 정전류 컨버터를 설계하고 제작된 SMPS의 전기적 특성을 측정하였다. 출력전류가 300mA 일 때 최대 85%의 효율을 나타내었으며 100~400mA의 범위에서는 70% 이상의 효율을 나타내었다. 또한 0~250mV의 제어신호를 이용하여 디밍레벨 0~100%의 범위를 모두 제어할 수 있었다.

• 한국정보기술학회 영문논문지
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• 제9권2호
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• pp.75-87
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• 2019

This paper presents a fully digital controlled power supply unit for the wireless controlled dimmable LED lighting system. The proposed power supply designed using a fly-back converter, which is directly controlled by a microprocessor. Although the proposed circuit does not sense the AC input current and has not AC input voltage feed-forward, it can achieve a high power factor. The proposed power supply directly regulates the output power for LED loads using the PWM and PFM control of the fly-back converter without additional regulator. For a wireless remote control function, the Zigbee modem is equipped in the proposed power supply. A prototype set-up has been built and tested. Through the experiment with a prototype set-up, the usefulness of the proposed power supply is verified.

• 설비공학논문집
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• 제22권11호
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• pp.788-797
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• 2010

This study examines the influence of fluctuating daylight illuminance on daylight dimming control systems. Field measurements were performed for a full-scale mocked-up model under various daylight conditions in winter. Fluctuating ranges for a partially-shielded photosensor were great when the variation of sky ratio was great. When solar altitude was lower the illuminance and fluctuating range of illuminance were great due to the influence of direct components of daylight and the interrefelction between surfaces in rear area of space. It implies that daylight dimming system would not function effectively, unless the desktop illuminance by daylight is enough. Fluctuation ranges of photosensor illuminance were lower than 50 lx under clear sky conditions, but they were greater than 100 lx under partly-cloudy sky conditions. It means that the fluctuation range of electric light output of lighting fixture would greater under the partly-cloudy conditions and cause potential visual annoyance to occupants. Outdoor vertical illuminance reaching the windows would be an effective factor that can be used to predict the fluctuation of photosensor signals for effective controls of daylight dimming system.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2012년도 춘계학술발표대회 논문집
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• pp.522-528
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• 2012

Currently, the energy consumption of electric lighting in an office building is accounted for more than 30% of the total energy consumption. In order to reduce the energy consumed by the indoor lighting, the daylight as a natural energy resource can play an important role in energy savings. The daylight can have positive impacts on improvement of work efficiency and productivity, and also make people feel more psychologically stable. Moreover, by using the daylight, we can definitely reduce the energy consumption in office buildings. Thus, the purpose of this study is to determine the LED dimming ratio depending on the ratio by calculating the amount of artificial illumination required according to the change of daylight by using the light simulation software that can quantify and visualize the performance of daylight. As a result, the energy savings could be obtained up to 30%.

• 융합정보논문지
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• 제7권3호
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• pp.97-103
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• 2017

본 논문에서는 가시광 통신 시스템에서 디밍 제어를 위한 Zero Reduction Code (ZRC)의 다양한 부호화율 및 채널 조건에서 성능 분석을 진행함으로써, ZRC 부호의 특성 일반화 고찰을 목표로 한다. 이를 위해 무선 광 통신 시스템의 LOS (Line-Of-Sight)와 NLOS (Non-LOS) 채널의 특성을 설명하고, (5, 4), (6, 5), (7, 6)ZRC 부호화율에서 디밍 과 BER (Bit Error Rate)측면에서 모의실험을 통해 성능 분석을 진행하였다. 모의실험 결과, 3가지 타입의 부호화율에서 디밍 성능은 비슷하지만, NLOS 채널 환경에서 RMS (Root Mean Square) 지연 확산 값이 증가 될수록 상대적으로 높은 부호화율의 ZRC코드가 좋은 BER성능을 달성하는 것을 확인 하였다. 따라서 향후 가시광 통신시스템에서 ZRC를 이용한 디밍 제어 기술을 설계할 때 본 연구에서 분석한 결과를 통해 채널 상태에 따른 부호화율을 결정하는데 도움이 될 것으로 예상된다.

• 조명전기설비학회논문지
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• 제22권12호
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• pp.20-28
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• 2008

에너지 자원의 고갈과 환경오염으로 인하여 건축조명 분야에서는 주광을 이용하여 에너지를 절약하는 연구가 활발히 진행되고 있다. 광센서 조장제어시스템은 실내로 입사되는 주광에 따라 인공조명을 자동으로 제어하는 에너지 절약형 시스템으로 쉐이딩 시스템에 의해 주광유입이 차단되어 그 적용성이 미비하다. 자동롤러쉐이딩 시스템은 태양의 변화에 따라 롤러쉐이드의 높이를 자동으로 제어하는 시스템으로 광센서 조광제어시스템과 통합되어 사용될 때, 불쾌한 직사일광은 차단하고 실내로 유용한 주광을 유입함으로써 에너지 절감과 쾌적한 시환경을 제공할 수 있다. 본 연구는 광센서 조광제어시스템과 자동롤러쉐이딩 시스템의 통합을 위하여, 각 시스템의 제어 소프트웨어를 개발하였고 이를 통합하였다.

• 한국태양에너지학회 논문집
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• 제32권3호
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• pp.50-58
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• 2012

The objective of this study is to evaluate the lighting dimming rates with various parameters of the building skin in a small office. We compared to simulated workplane illuminance and measured workplane illuminance for the base model. After that, the five veriables(the presence of vertical wall in double skin facade, the presence of windowsill, window to wall ratio(WWR), window visible transmittance, the width of double skin facade) were applied to base model, and we analyzed the simulated lighting energy saving rates. The results are listed as below. The simulated workplane illuminance results are similar to the measurement. Simulated illuminance was smaller than measured illuminance by 16.5%(60 lx). In accordance with applicable building skin parameters, lighting energy saving rate results are summarized as follows. Lighting energy saving rate of case1(windowsill height 0.7m) is higher than that of base case(windowsill and vertical wall) by 7.3% and the lighting energy saving rate of case2(no vertical wall) is higher than that of base case by 7.6% and the lighting energy saving rate of case3(no windowsill and vertical wall) is higher than that of base case by 12.4%. The lighting energy saving rate is increased by 2.3%, when window visible transmittance is increased from 70% to 86%. The lighting energy saving rate is increased by 4.6%, when we changed the WWR 70% to 90%. lighting energy savings rate is increased by 6.5%, when the width of double skin facade is reduced from 1m to 0.3m.

• 조명전기설비학회논문지
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• 제27권2호
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• pp.14-21
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• 2013

Today, energy problem has become an important issue, and a development of renewable energy is urgent. In architectural fields, a research of the energy efficient lighting system using renewable energy is in progress. The energy efficient lighting system could be realized by integrating a daylight responsive LED lighting control system and a blind PV system. This system is able to save and generate electric energy. Efficiency of this system depends on control methods of blind PV. As a preliminary research, this research analyzed power generation and inflow of available daylight according to control method of blind PV.

• 조명전기설비학회논문지
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• 제27권12호
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• pp.44-53
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• 2013

This study has attempted to investigate how subjects perceive changes of brightness and their visual comfort according to daylight responsive LED(Light Emitting Diode) dimming systems in the office with venetian blind. Two studies was conducted. First study is that how subjects perceive changes of brightness and their visual comfort depending on angle control method of the venetian blind while the workplane illuminance level is being maintained through daylight responsive LED dimming system. Second study is that how subjects perceive changes of brightness and their visual comfort depending on the amount of daylight penetrated into the building while the illuminance level is being maintained through daylight responsive LED dimming system. The results of this study could be proposed as basic data in the control of the venetian blind and LED lighting in consideration of their perception on changes of brightness and visual comfort.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 2부
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• pp.502-506
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• 2012

본 논문은 LED 조명 환경에서 Zigbee를 이용해서 Dimming 제어 모듈을 구성 하였다. 현재 사용되고 있는 LED 제어 모듈는 일반적으로 단일 출력을 사용하여 LED 조명의 일정한 밝기를 고정 출력이 되도록 사용되어지고 있다. 본 논문에서 구성된 무선 통신 모듈은 Zigbee를 이용하여 실내 환경에서 측정된 조도값을 무선으로 전송하도록 조도 센서 모듈을 구성 하였으며, 무선으로 전송된 조도값에 대한 출력을 제어하도록 구성하였다. MCU는 LED Driver IC를 이용하여 PWM 신호에 따라서 LED Driver IC에서 출력 전압을 변화하도록 하여 6단계의 밝기로 LED조명을 Dimming하도록 구성하였으며, 무선조도 센서는 10~15m의 거리에서 안정적으로 동작된다.