• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.1
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• pp.21-28
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• 2005

As the maximum power operating point(MPOP) of the Photovoltaic(PV) power systems alters with changing atmospheric conditions, the efficiency of maximum power point tracking(MPPT) is important in PV power systems. Many MPPT techniques have been considered in the past, but techniques using microprocessors with appropriate MPPT algorithms are favored because of their flexibility and compatibility with different PV arrays. In this paper, the author analyzes and studies two MPPT algorithms, which is named P&O(Perturbation and Observation) and IncCond(Incremental Conductance). Also, the author proposes Hysterisis-band alteration algorithm. To show the excellency of new Hysterisis-band alteration, the author suggests three references; 1) Comparing three MPPT algorithms in the steady-state condition, 2) Representing irradiation variation rapidly, 3) Showing MPPT efficiency. MPPT simulation and experiment perform in the boost converter.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.521-531
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• 2011

This paper presents the variable perturbation and observation(VPO) maximum power point tracking(MPPT) control of the photovoltaic(PV) system considering the shadow influence. The output characteristics of the solar cell is a nonlinear and affected by a temperature, the solar radiation and influence of a shadow. MPPT control is a very important technique in order to increase an output and efficiency of the solar power generation. Conventional perturbation and observation(PO) and incremental conductance(IC) are the method finding MPP by the continued self-excitation vibration. The MPPT control is unable to be performed by rapid output change affected by the shadow. To solve this problem, this paper proposes the VPO MPPT algorithm which changes step size according to output variation. The response characteristics of VPO MPPT algorithm proposed in this paper compares with response characteristics of conventional MPPT algorithm about the radiation, temperature and shadow influence. The validity of the algorithm proposed in this paper prove through the results of the comparisons.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.75.2-75.2
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• 2011

국내 유인도서의 상당수는 전력의 대부분을 디젤발전으로 생산한다. 향후 발전설비의 교체 혹은 증설이 있을 경우 신재생에너지원 설비의 보급 여지가 있다. 이에 본 연구는 울릉도에 화력발전 설비만을 증설했을 경우와 이를 신재생에너지복합시스템 설비로 대체했을 때의 경제적 타당성을 비교분석한다. 우리는 복합발전 시스템을 풍력터빈, PV, 소수력발전 등의 신재생에너지 설비, Batteries, Converter와 같은 보조전원, 저장 및 back up을 위한 flywheel과 Diesel generator등으로 구성했다. 분석에 사용한 HOMER(Hybrid Optimization for Energy Renewable)는 신재생에너지복합 발전시스템 분석에 사용되며 결과를 NPC(Net Present Cost)의 오름차순으로 제시하여 발전설비구성의 조합들 중 최적의 시나리오를 보여준다. 분석결과 울릉도의 경우 신재생에너지복합 발전의 보급이 잠재적으로 가능할 것으로 보인다. 또한 계통운영의 기술적인 측면을 감안할 경우 정밀한 분석이 가능할 것이다. 따라서 본 연구는 계통운영과 경제성분석 연구의 연계를 위한 사전연구로써 그 의미를 갖는다.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.561-569
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• 2019

Solar photovoltaic can provide electrical energy with only radiation, and its use is expanding rapidly as a new energy source. This study predicts the short and long-term PV power generation using actual converter output data of photovoltaic system. The prediction algorithm uses multiple linear regression, support vector machine (SVM), and deep learning such as deep neural network (DNN) and long short-term memory (LSTM). In addition, three models are used according to the input and output structure of the weather element. Long-term forecasts are made monthly, seasonally and annually, and short-term forecasts are made for 7 days. As a result, the deep learning network is better in prediction accuracy than multiple linear regression and SVM. In addition, LSTM, which is a better model for time series prediction than DNN, is somewhat superior in terms of prediction accuracy. The experiment results according to the input and output structure appear Model 2 has less error than Model 1, and Model 3 has less error than Model 2.

• Journal of the Korean Society of Radiology
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• v.5 no.3
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• pp.127-134
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• 2011

In this paper we propose an improved PV generation systems. Improved systems for temperature and humidity controlled heating and air conditioning offers a pleasant environment within the building, set up chopper and consists of a PWM voltage type inverter. The proposed system is stable modulation for a one-chip microprocessor using the synchronous signal and control signals was treated. The proposed system is a PWM voltage type inverter and phase of the synchronous to the grid voltage to detect the system voltage and inverter output to drive the statue, so surplus power to connection was able to, certain buildings such as buildings or hospitals, temperature and humidity sensor is applied to the good dynamic characteristic could be obtained. In addition, the system was applied to the high power factor and low-frequency harmonics by maintaining the output load and grid to power to be supplied to a stable control could get a good result.

• Journal of Advanced Navigation Technology
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• v.26 no.1
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• pp.35-45
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• 2022

In this paper, we modeled the devices used easily in PV system circuits. In addition, for full operation of the photovoltaic system, a complete operation system for the DC-DC buck-boost converter and the MPPT control system was modeled and simulated to confirm good operation. we were constructed an actual system with the same conditions in the simulation and experimented. The purpose is to confirm the stable power supply through the load leveling by presenting the PCS considering ESS of photovoltaic power generation. we will do study to apply hybrid capacitors that have high energy density to the same size compared to the EDLC to DVR. As a result, we proposed a single-phase 3 kW grid-connected solar power converter.

• Journal of the Korean Solar Energy Society
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• v.31 no.2
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• pp.82-88
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• 2011

The artificial increase in the solar intensity incident on solar cells using lenses or mirrors can allow solar cells to generate equivalent power with a lower cost. There are two types of concentration optics for solar energy conversion. One is to use mirrors, and the other is to use Fresnel lenses. The gains that can be achieved with a Fresnel lens or a parabolic mirror are compared. The result showed the gains are comparable and the two configurations were developed competitively. In application areas of Fresnel lenses as solar concentrators, several variations of design were devised and tested. Some PV systems still use commercially available flat Fresnel lenses as concentrators. A convex linear Fresnel lens to improve the concentration ratio and the efficiency is devised and flat linear Fresnel lens in thermal energy collection is utilized. In this study, we designed and optimized flat Fresnel lens and the 'light pipe' to develop 500X concentrated solar PV system. In the process, we compare the transmission efficiencies according to groove types. We performed rigorous ray tracing simulation of the flat Fresnel lenses. The computer aided simulation showed the 'grooves in case' has the better efficiency than that of 'grooves out case'. Based on the ray-trace results we designed and manufactured sample Fresnel lenses. The optical performance were measured and compared with ray-trace results. Finally, the optical efficiency was measured to be above 75%. All the design and manufacturing were performed based on that InGaP/InGaAs/Ge triple junction solar cell is used to convert the photon energy to electrical power. Field test will be made and analyzed in the near future.

• Journal of IKEEE
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• v.13 no.2
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• pp.175-180
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• 2009

This paper compare the operation characteristic and optimal design of Photovoltaic system by computer simulation. The operation characteristic of Photovoltaic system are evaluated and analyzed considering system parameters of specifications, installations, inclination, azimuth and surrounding conditions etc. From the basis of these results, this study will intend to develop an evaluation, analysis tool and construct database for optimal design of PV system.

• Bulletin of the Korea Photovoltaic Society
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• v.3 no.1
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• pp.61-67
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• 2017

Concentrated solar power(CSP) is receiving attention for its ability to generate dispatchable power from heat stored in thermal energy storage(TES). There are currently four types of CSP technology, however experts expect that only parabolic trough and solar tower are to survive from the market due to its higher efficiency and larger capacity in storage. While the initial cost for installing CSP plant is still expensive, the experts expect that investment cost of CSP would decline to the level which would be competitive with PV or wind in the near term future. In addition, further growth in its installation capacity is expected due to the United States and China's aggressive investments in CSP.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.1
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• pp.93-107
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• 1997

A solar cell is a device which converts solar energy into electricity without any polluting by-product. Solar cells are useful when they are connected together to form modules. Total production of PV modules worldwide jumped 20 % in 1995 to reach a new record 84.8 MW. In this paper, the recent market trends in photovoltaic industries, principles and characteristics of solar cells and photovoltaic systems are reviewed.