• 전력전자학회:학술대회논문집
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• 전력전자학회 2005년도 전력전자학술대회 논문집
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• pp.61-63
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• 2005

Utility interactive photovoltaic systems is one of the most premising applications of photovoltaic systems. These systems are employed in applications where utility service is already available. In this case, there is no need for battery storage because utility power may be used to supplement photovoltaic systems when the load exceeds available PV generation. The load receives electricity from both the photovoltaic array and the utility inter-tied. In this paper, Principle and operating characteristic of Utility Interconnected Photovoltaic System is presented. For the purpose of optimal utility Inter-tied photovoltaic system design and installation. It is that demonstrate throughout the installed 3 PV system respectively, 3kW utility interconnected residential system.

• Transactions on Electrical and Electronic Materials
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• 제18권2호
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• pp.103-110
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• 2017

The number of applications of solar photovoltaic (PV) systems in power generation grids has increased in the last decade because of their ability to generate efficient and reliable power in a variety of low installation in domestic applications. Various PV converter topologies have therefore emerged, among which the modular multilevel converter (MMC) is very attractive due to its modularity and transformerless features. The modeling and control of the MMC has become an interesting issue due to the extremely large expansion of PV power plants at the residential scale and due to the power quality requirement of this application. This paper proposes a novel control method of MMC which is used to directly integrate the photovoltaic arrays with the power grid. Traditionally, a closed loop control has been used, although circulating current control and capacitors voltage balancing in each individual leg have remained unsolved problem. In this paper, the integration of model predictive control (MPC) and traditional closed loop control is proposed to control the MMC structure in a PV grid tied mode. Simulation results demonstrate the efficiency and effectiveness of the proposed control model.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 2008년도 추계학술대회 논문집
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• pp.229-234
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• 2008

The new millennium has started with several innovations driven by fast evolution of the technologies in energy sector. A strong impulse towards the diffusion of new economical efficient technologies regulatory incentives related to energy production from renewable source and a small scale building trigeneration and to promotion of more sustainable environmental-friendly generation solutions, the evolution of electricity markets, more and more binding local emission constraints, and the need for improving the security of supply to reduce the energy system vulnerability. The 24 percentage energy quantify of total energy consumption consumes in commercial buildings and residential houses and the 30% portion of total $CO_2$ emissions covers also in the commercial buildings and residential houses sector. To cope with efficiently this energy sinuation in building sector, Building microgrid or building tooling, heating & power(BCHP) system has been interested in recent day due to meeting thermal and electric energy requirements efficiently and with appropriate energy quality. A multi agent system is a collective of intelligent agents that communicate with each other and work cooperatively to achieve common goals. Also, it is to medicate and coordinate communication between Control Areas and Security Coordinators for teal-time control of the BCHP system and the power pid. In this new circumstance, it is very important to integrate the power and energy delivery system and the information system(communication, networks, and intelligent equipment) that controls it. Therefore, development of smart control modules with open communication protocol and seamlessly interchange the data and information between control network and data network including extranet and intranet give a great meanings. We designed and developed the TCP/IP-CAN IED agent modules and ModBus./LonTalk/(TCP/IP) IED agent ones to configure the multi-agent system based smart energy network of commercial buildings and also intelligent algorithms for inverter fault diagnostics which ran be operated in control level or agent level network.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
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• pp.133-136
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• 2004

Since the residential load is an AC load and the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

• Journal of Power Electronics
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• 제16권1호
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• pp.153-162
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• 2016

Given their structural arrangement, photovoltaic (PV) modules exhibit parasitic capacitance, which creates a path for high-frequency current during zero-state switching of the converter in transformerless systems. This current has to be limited to ensure safety and electromagnetic compatibility. Many solutions that can minimize or completely avoid this phenomenon, are available. However, most of these solutions are patented because they rely on specific and often complex converter topologies. This study aims to solve this problem by introducing a solution based on a classic converter topology with an appropriate modulation technique and passive filtering. A 5.5 kW single-phase residential PV system that consists of DC-DC boost stage and DC-AC H-bridge converter is considered. Control schemes for both converter stages are presented. An overview of existing modulation techniques for H-bridge converter is provided, and a modification of hybrid modulation is proposed. A system prototype is built for the experimental verification. As shown in the study, with simple filtering and proper selection of switching states, achieving low leakage current level is possible while maintaining high converter efficiency and required energy quality.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 A
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• pp.443-445
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• 1995

Since the residential load is an AC load, while the output of solar cell is a DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell and must provide the sinusoidal wave current and voltage with unity power factor in the case of driving to Interact with utility line. It is always necessary for the output of solar cell to operate in the vicinity of maximum power point, since it is greatly fluctuated by insolation. This paper treats that we will constitute a single phase PWM voltage source inverter and trace the modulation index which always maximize the output of solar cell in propotion to insolation variation and prove it by simulation that we can provide current wave, which is nearly sinusoidal wave with unity power factor, for load and utility line.

• 한국정보전자통신기술학회논문지
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• 제7권1호
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• pp.20-25
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• 2014

차세대 친환경 조명인 LED소자는 온도가 올라갈수록 LED의 발광효율이 떨어지고 $80^{\circ}C$이상 올라갈수록 수명이 감소하고 스펙트럼선의 파장이 본래의 파장보다 장파장 쪽으로 이동하는 Red Shift현상 및 $T_j$ 상승에 따라 광 출력이 감소되는 큰 문제점이 대두되고 있어 열을 최소화 할 수 있는 방열설계 연구가 진행 중이다. COB Type LED의 경우 보드에 LED 칩을 직접 결합시켜 열 저항을 낮췄지만 주거용 13.5W의 경우 방열판을 통해 발열 문제를 해결해야한다. 본 논문에서는 주거용 13.5W COB LED 다운라이트에 맞게 Heat Sink를 설계하고, 그 설계한 Heat Sink와 13.5W COB를 패키징하여 Solidworks flow simulation을 통해 최적의 Fin두께를 선정하여 접촉식 온도계를 사용한 열적 특성을 분석 하고 평가 하였다.

• 전기학회논문지P
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• 제54권3호
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• pp.111-118
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• 2005

Since the residential load is an AC load and the output of solar cell is DC power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation, it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper, DC/AC converter is three phase PWM converter with smoothing reactor. And then, feed-forward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.

• 전기학회논문지
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• 제62권1호
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• pp.63-69
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• 2013

In recent years, technology for storing a preliminary power or a surplus of photovoltaic energy is required. This technique, as well as store a preliminary energy and improve the reliability of the gird safety. This system can plan a efficient power generation through the flexibility of the power supply from the perspective of not only provider but also user. Accordingly, the realization of the smart grid can be expected. This paper proposes a hybrid PCS using a photovoltaic and a lithium-polymer battery with the characteristics of high density energy. The main energy source of a hybrid PCS is a photovoltaic, grid and the auxiliary energy source is a lithium-polymer battery. The operation of a proposed system in this paper is verified with simulation and experimental results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 B
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• pp.1253-1255
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• 2003

Since the residential load is an AC load and the output of solar cell is a DC Power, the photovoltaic system needs the DC/AC converter to utilize solar cell. In case of driving to interact with utility line, in order to operate at unity power factor, converter must provide the sinusoidal wave current and voltage with same phase of utility line. Since output of solar cell is greatly fluctuated by insolation. it is necessary that the operation of solar cell output in the range of the vicinity of maximum power point. In this paper DC/AC converter is three phase PWM converter with smoothing reactor. And then, feedforward control used to obtain a superior characteristic for current control and digital PLL circuit used to detect the phase of utility line.