• 한국통신학회논문지
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• 제42권5호
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• pp.1093-1101
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• 2017

스마트 그리드를 구성하는 기본 단위 요소인 마이크로그리드(Microgrid)는 전력의 중앙 공급방식에서 벗어나 독립된 하나의 체계를 이룬다. 본 논문은 전력변환장치(Power Conditioning System)를 기반으로 마이크로그리드를 계통으로부터 전기적으로 독립시키고, 신재생 에너지원과 에너지 저장장치(Energy Storage System) 등의 분산자원(Distributed Energy Resource)을 활용하여 효과적으로 독립 상태를 유지하고 운영할 수 있는 방법을 제안한다. 계통의 위상검출과 동기화를 통해 계통에 연계하거나 독립 시에 부하에 미치는 영향을 최소화할 뿐만 아니라 계통의 정전 상황에서도 안정적으로 운영이 가능하다.

• Journal of Power Electronics
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• 제13권2호
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• pp.296-303
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• 2013

This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.

• 설비공학논문집
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• 제25권2호
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• pp.55-63
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• 2013

For a large-scale semiconductor manufacturing clean room, the energy consumed in an outdoor air conditioning system to heat, humidify, cool and dehumidify incoming outdoor air is very large. In particular, the energy requirement to humidify outdoor air in the winter season is generally known to be high. Recently, in order to overcome the high energy consumption nature of a steam generator in a conventional steam humidification type outdoor air conditioning system, an air washer is often introduced instead of the steam generator in the outdoor air conditioning system, which can be called a water spray humidification type outdoor air conditioning system. Therefore, the assessment and comparison of the annual energy consumed in the steam humidification type and the water spray humidification type outdoor air conditioning systems deserves to be examined in order to reduce the outdoor air conditioning load of a clean room. In the present study, a numerical analysis was conducted to obtain the annual electric power consumption of the two outdoor air conditioning systems. It was shown from the comparison of the numerical results that the water spray humidification type outdoor air conditioning system can reduce about 30% of annual electric power consumption of the steam humidification type outdoor air conditioning system.

• 전력전자학회논문지
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• 제7권6호
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• pp.563-569
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• 2002

본 연구는 60Hz 절연변압기가 없는 형태의 고주파링크방식의 계통연계형 PCS(Power Conditioning System)를 개발하였다. 본 시스템은 고주파 DC-DC 컨버터, 고주파 절연변압기, 풀브리지 다이오드 정류기, DC filter, 저주파 인버터, LC 필터로 구성되어 있다. 고주파 DC-DC 컨버터는 20kHz의 bipolar PWM 펄스를 발생시키며, 이 펄스는 고주파 절연변압기를 통해 승압되고, 풀브리지 다이오드를 통해 정류된다. 마지막으로 저주파 인버터를 통해 정현파 전류가 계통에 유입되게 된다. 제안한 고주파링크방식의 시스템은 기존의 60Hz 절연변압기를 사용하는 시스템 보다 많은 스위칭 소자가 사용되지만, 60Hz 절연변압기를 생략함으로서 시스템의 소형경량화 및 저가화를 이룰 수 있었다.

• 제어로봇시스템학회논문지
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• 제20권9호
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• pp.984-993
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• 2014

In this paper, we propose a design for an efficient hybrid LED street lighting management system using standalone solar photovoltaic. The proposed efficient hybrid LED street lighting management system was composed of hybrid power conditioning system, gateways, LED street lights and a monitoring server. The hybrid power conditioning system was designed to charge produced power by solar photovoltaic panels in day time, and supply power to the LED street lights in night time. If there is insufficient power, the system was designed to operate using firm power, because the system utilizes photovoltaic power. A system control algorithm allied to the lighting management system, and experimented by being configured to the functions that are able to perform real-time monitoring and remote control through the lighting management system even when absent. In the result of the efficiency analysis of the hybrid lighting management system proposed in this paper, we were able to increase the energy efficiency compared to existing lighting control systems by reducing power consumption and electricity costs.

• Journal of Power Electronics
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• 제5권4호
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• pp.289-304
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• 2005

This paper describes a simple control structure and power conditioning system for an indirect vector controlled stand-alone induction generator (IG) used to operate under variable speed. The required reactive power for the IG system is supplied by means of a capacitor bank and a voltage-source PWM converter. Using a capacitor bank to transfer the reactive power to the IG under the rated speed and no-load conditions starts the IG operation and reduces the PWM converter size. The vector control structure for the variable speed IG power conditioning system compensates for changes in the electrical three-phase and DC loads while considering the magnetizing curve of the IG. The vector control structure is developed to regulate the DC link voltage of the PWM converter and the IG output voltage. The experimental and simulated performance results of the IG power conditioning system at various speeds and loads are given and show that this proposed scheme can be used efficiently for a variable speed, wind energy conversion system.

• Journal of Advanced Marine Engineering and Technology
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• 제15권5호
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• pp.38-46
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• 1991

In the design of an electric power plant, the capacity to meet the peak load demand is one of the important factors to be considered. This peak load usually occurs when the most of the cooling air-conditioning systems are being operated during daytime in summer season. Therefore, it is necessary to construct an additional electric power plant and to develop the new air-conditioning system for relieving the peak load. This paper analysed the performance characteristics of this experimental regenerative ice energy system by means of a bundle of the heat-pipes. And the result of this analysis was applied to the simulation of an air-conditioning system model. Also, an operation program of moisture air was made according to air load and in order to computerize the air-conditioning system a CAD program was developed by the properties of moisture air.

• 대한설비공학회지:설비저널
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• 제15권1호
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• pp.48-57
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• 1986

• 대한설비공학회지:설비저널
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• 제3권2호
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• pp.105-110
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• 1974

• Journal of Electrical Engineering and Technology
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• 제5권4호
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• pp.561-570
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• 2010

This paper presents an advanced dynamic simulation model of a proton exchange membrane fuel cell for the optimal design of a fuel cell power conditioning system (FC-PCS). For the development of fuel cell models, the dynamic characteristics of the fuel cell are considered, including its static characteristics. Then, software fuel cell simulation is realized using Matlab-Simulink. Specifically, the design consideration of PCS (i.e., power semiconductor switch, capacitor, and inductor) is discussed by comparatively analyzing the developed simulator and ideal DC source. In addition, a cosimulation between the fuel cell model and PCS realized using the PSIM software is performed with the help of the SimCoupler module. Detailed analysis and informative simulation results are provided for the optimal design of fuel cell PCS.