• 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.

• 한국수소및신에너지학회논문집
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• 제17권3호
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• pp.338-346
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• 2006

In this paper, the test results of medium-size(120 kW class) PV system which was installed in the Taeahn thermal power station of Korea Western Power Co., Ltd., were summarized for developing the practical technology to applicate high voltage grid connection PV system. The 120 kW photovoltaic system which was consisted of 1,300 modules, PCS, and 150 kVA transformer station has been operated since Aug. 05, 2005. For verifying the modeling results of PV system, the operation data was compared with modeling results which was executed commercial PSCAD/EMTD and Psim tools. An equivalent circuit model of a solar cell has been also used for solar array modeling. A series of parameters required for array modeling have been estimated from general specification data of a solar module. A PWM voltage source inverter(VIS) and its current control scheme have been analyzed by using P&O (perturbation and Observation) MPPT algorithms technique.

• 한국수소및신에너지학회논문집
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• 제29권4호
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• pp.363-369
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• 2018

This paper considers the alternative way to mitigate cost for REC instead of Photovoltaic (PV) panels with Energy Storage System (ESS). This study starts from an economic analysis of a 1 megawatt PV system without ESS. Several assumptions have been applied in consideration of the current domestic situation. Based on this result, the economic efficiency of PV with ESS improved. However, the reliance on government subsidies was very high. The alternative way to cover the fluctuation power from renewable energy was reviewed with economical and technical way. In case the natural gas engine applied to PV, the IRR and Levelized Cost of Electricity (LCOE) can be improved without ESS. And if small amount of additional REC, the IRR can be improved up to investment level.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.91-100
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• 2000

An operating principle of PID module was implemented using the load, where the integer in a PID measuring derivate equation were valid in the ranges of 500-9000, 60-1000, and 000-9000, for P, I and D, respectively. A load operation program was designed to investigate the PID theory and its realization process. With it, it was examined the process that the current PV tracts the target SV, By investigating the time when the PV approaches the SV and the rate at which the EV is varied, it is revealed that 1) larger (or Smaller) Kp leads to faster (or slower) approaching of PV to SV, 2) smaller (or larger) Ti results in faster (or slower) approaching of PV to SV, 3) larger (or smaller)$T_d$ causes smaller (or Larger) rate variation in the EV. These observation were found to coincide with those of PID operating characteristics. Though this implementation, it is known for the widespread use of PID module that an improvement should be made in the error of temperature. This, meanwhile, implies that the computational time of conventional manipulation valve must be faster than 0.1 second. It is demanded that an improved PID module including the A/D and D/A module, in itself must be used in conjunction with PLC.

• 한국화재소방학회논문지
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• 제28권6호
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• pp.47-51
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• 2014

본 연구에서는 태양광 발전설비가 설치되어 있는 건물에서 화재가 발생할 경우 분사되는 물을 통해 전류가 흐를 가능성 및 감전의 위험성에 대해 고찰하였다. 분사되는 물을 수학적 모델을 통하여 해석 하였고, 물 전도도 측정을 위한 물분사 시스템을 제작하여 유속에 따른 물 저항값을 측정하여 수치적으로 예상한 값과 비교하였다. 실험과 수치계산의 결과로 태양광 발전설비 화재 시 고려되어야 할 사항들을 정의할 수 있게 되었다.

• 한국태양에너지학회 논문집
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• 제28권6호
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• pp.87-92
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• 2008

Buildings are responsible for approximately 50% of current carbon dioxide emissions. Energy planning at a town and city scale needs a strategic approach, supported by strong planning policies. The purpose of this study was to investigate the urban scale grid-connected photovoltaic(PV) system for urban residential and commercial sector applications. The integration of PV technology into roof of houses is an approach that is being championed in Germany, Japan and United states etc. In the Korea, PV roofing systems already are given the large number of houses which are projected to be built by 2012. However unlike germany and Japan, urban scale grid-connected PV system is not yet installed. The solar city which is installed building-integrated photovoltaic system is available to use of renewable energy sources such as solar to meet demand, instead of fossil fuels, with the goal of realizing an ecologically oriented energy supply.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.98-103
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• 2009

In this paper, we test the electrical resistance of flat wire in the PV module. normally solar cell has two kind of flat wire(inter connection ribbon and bus bar ribbon). we found the phenomenon that has a unbalance with resistance when we make a wiling between of string. So, we measurement the resistance of flat wire each other. and analysis of missmatch with resistance between flat wires on PV module. next to survey of IR picture on missmatch flat wire samples for analyze of missmatch with current in the wire. and we perform IR test with solar cell that has a connection with flat wire for test the effect of missmatch resistance on solar cell. Finally we perform the Dark I-V test for survey of effect by the unbalance of resistance. By the result of Dark I-V test, the series resistance of existing connection sample is large more then innovated connection sample.

• 한국태양에너지학회:학술대회논문집
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• 한국태양에너지학회 2009년도 추계학술발표대회 논문집
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• pp.246-250
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• 2009

String & tabbing step in the crystalline PV module manufacturing process for the temperature directly affects solar cells. In fact, in the manufacture of PV modules tend to be temperature factor and the corresponding changes n the output shows the same characteristics. In this journal, it will be considered about thermal characteristics, especially changes of characteristic in high temperature of the solar cell through experiment that we measure electric output characteristics of solar cells after those are applied with high temperature changes for two seconds. And we can think about the possibility of efficiency improvements over looks in PV module manufacturing processes.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2007년도 하계학술대회 논문집
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• pp.74-76
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• 2007

In this paper a maximum power point tracking(MPPT) techniques for power of PV(photovoltaic) systems are presented using boost converter for a connected single phase inverter. On the basic principle of power generation for the PV module, algorithms for maximum power point tracking are described by utilizing a boost converter to adjust the output voltage of the PV module. Based on output power of a boost converter, single phase inverter uses predicted current control to control four IGBT's switch in full bridge. Furthermore a low cost control system for solar energy conversion using the DSP is developed, based on boost converter to adjust the output voltage of the PV module. The effectiveness of the proposed inverter system is confirmed experimentally and by means of simulation. Finally, experimental results confirm the superior performance of the proposed method.

• Journal of Electrical Engineering and Technology
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• 제13권3호
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• pp.1131-1137
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• 2018

In this paper, the authors suggest a new control algorithm for a three-phase four-wire photovoltaic (PV) inverter with imbalance load compensation function using conventional proportional-integral (PI) controllers. The maximum power of PV panel is calculated by the MPPT control loop. The reference varying signals of current controllers are transformed to two different rotating frames where they become constant signals. Then simple PI controllers are applied to achieve zero steady-state error of the controllers. The proposed control algorithm are modeled and simulated with imbalance load configuration to verify its performance. The simulation results show that the maximum PV power is transferred to the grid and the imbalance power is compensated successfully by the proposed control algorithm. The inverter has a fast response (~4 cycles) during the transient period. The proposed control algorithm can be effectively utilized to the three-phase four-wire inverter with imbalance load compensation function.