• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.35 no.6
• /
• pp.551-560
• /
• 2011

In this paper, a cooling system that includes a heat spreader and a natural convective heat sink is proposed for the cooling of a concentrating photovoltaic (CPV) module. The heat spreader and the natural convective heat sink are designed on the basis of previous analytical investigations. In order to evaluate the proposed cooling system, we conducted experimental investigations varying the heat rate and the inclined angle of the cooling system. From the experimental results, it is found that the proposed cooling system satisfies the design constraints for good operation of the CPV module. Finally, a correlation is suggested for estimating the effects of the heat rate and the inclined angle on the thermal performance of the natural convective heat sink is suggested.

• Proceedings of the Korean Society of Disaster Information Conference
• /
• 2022.10a
• /
• pp.427-428
• /
• 2022

최근 대규모 항만 건설 및 기존 부두 리모델링과 같은 해안 공간 구조물 확충사업이 활발하게 진행되고 있으며 항만 구조물 거동 장기계측을 위한 센서에 대한 관심도 높아지고 있다. 기존의 항만에 적용한 전기식 센서들은 수개월 정도 단기간의 구조물 거동 측정은 가능하지만 수년 이상의 장기계측 시 염수분에 의한 부식 및 내구성에 취약하기 때문에 원활한 측정에 한계점이 있고 센서 설치를 위한 항만 외곽지역 구조물과 육상전원공급설비 배전반 사이의 거리로 인하여 긴 연장의 횡단로 가설전선 보호대 등을 설치해야 하는 어려움이 있다. 따라서, 본 연구에서는 항만 구조물 거동 장기계측을 위해 기존 전기식 센서들의 부식문제점을 파악하여 해수용 4종 센서 IoT 모듈 패키징을 설계하고 외부 전원공급 방해 영향을 최소화한 태양광 발전을 적용한 항만 구조물 거동 계측 시스템을 제안하였다.

• Journal of the Society of Disaster Information
• /
• v.14 no.2
• /
• pp.130-140
• /
• 2018

Purpose: In this paper, we propose a design technique for the safety characterization grounding in the construction of the photovoltaic power generation complex which can be useful and useful as an alternative power energy source in our society. In other words, we will introduce the application of safety grounding for each application, which can improve and optimize the reliability of the internal grid from the cell module to the electric room in the photovoltaic power generation complex. Method: We analyze the earth resistivity of the soil in the solar power plant and use the computer program (CDEGS) to analyze the contact voltage and stratospheric voltage causing the electric shock, and propose the calculation and calculation method of the safety ground. In addition, we will discuss the importance of semi-permanent ground electrode selection in consideration of soil environment. Results: We could obtain the maximum and minimum value of ground resistivity for each of the three areas of the data measured by the Wenner 4 - electrode method. The measured data was substituted into the basic equation and calculated with a MATLAB computer program. That is, it can be determined that the thickness of the minimum resistance value is the most favorable soil environment for installing the ground electrode. Conclusion: Through this study, we propose a grounding system design method that can suppress the potential rise on the ground surface in the inner grid of solar power plant according to each case. However, the development of smart devices capable of accumulating big data and a monitoring system capable of real-time monitoring of seismic changes in earth resistances and grounding systems should be further studied.

• Proceedings of the KIPE Conference
• /
• 2014.11a
• /
• pp.177-178
• /
• 2014

본 논문에서는 기존에 널리 사용되고 있는 3상 인버터와 태양광 인버터 및 무정전 전원공급시스템의 고효율화를 위해 최근 적용이 확대되고 있는 3상 T형 3-레벨 인버터에서 각 전력 반도체에서 발생하는 손실을 구하고 그 결과를 비교, 분석하였다. 또한 그 손실 특성을 기초로 해서 3상 50kVA급 기존 3상 인버터 및 3상 T형 3-레벨 인버터 전력변환모듈을 설계하였고 전산유체해석 소프트웨어를 이용해서 전력변환모듈 내부 방열판의 상세 온도 분포를 해석하고 그 비교 분석 결과를 제시하였다.

• Journal of Aerospace System Engineering
• /
• v.17 no.4
• /
• pp.10-17
• /
• 2023

This paper describes the research and development of a 3.0 m Solar-Powered UAV system for mission flight that is based on the 4.2 m Solar-powered UAV. Both the Solar-Powered UAVs were lightened in weight by applying a composite fuselage and solar charging system. Also, a deep stall landing application and airbag module were installed for usability in mission performance. The flight performance of the Solar-Powered UAV system was verified through flight test. In particular, the 3.0 m Solar-Powered UAV performed continuous flight along the coastline of Jeju Island for 147 km in 3 hours and 50 minutes, and its performance as a mission flight was also confirmed.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1128_1129
• /
• 2009

본 논문에서는 Ni-MH전지를 가로등용 독립형 태양광발전시스템의 전력저장장치로 적용하고 충방전제어기를 설계하고 시스템을 구성하여 운전특성을 분석하였다. 태양전지모듈은 170W Sanyo사의 HIP-170N1을 사용하였고 전력저장장치는 Ni-MH 전지를 적용하였으며 부하인 가로등용 램프로는 24V, 45W 삼파장 램프를 사용하여 가로등용 독립형 태양광발전 시스템을 구성하였다. 또한 충방전 제어기를 구성하여 Ni-MH 전지의 충방전 특성을 분석하였다. Ni-MH 전지의 충방전 전압은 27V 좌우로 안정적으로 충방전이 되고 있음을 알 수 있었으며 축전지의 온도 상승도 15시 이후에 최고 $35^{\circ}C$로 나타났다. 이는 Ni-MH전지에 적용한 충전 시스템이 온도에 의하여 충전 말기 전압을 제어하기 때문으로써 축전지의 과충전 현상을 방지하여 축전지의 수명을 증가할 수 있을 것으로 판단되어진다.

• Journal of Energy Engineering
• /
• v.29 no.1
• /
• pp.44-51
• /
• 2020

The importance of ESS has been emphasized due to stabilization of power demand due to deterioration of network reliability and expansion of renewable energy sources. ESS (Energy Storage System) stores the remaining power and uses it when necessary to meet the power demand, and build the ESS system mainly in conjunction with solar and wind power. In this paper, we propose a home PV Charging Module using the Master-Slave method which is effective for low insolation. After designing the module, Fast MPPT algorithm is applied to generate the maximum output from the nonlinear output characteristics of the PV modules. The average power value for the input of PV Charging Module was 296.90 W and the output power was 289.60 W, which averaged 97.54%.

• Journal of KIISE:Software and Applications
• /
• v.41 no.7
• /
• pp.481-491
• /
• 2014

The power production using renewable energy is more important because of a limited amount of fossil fuel and the problem of global warming. A concentrative photovoltaic system comes into the spotlight with high energy production, since the rate of power production using solar energy is proliferated. These systems, however, need to sophisticated tracking methods to give the high power production. In this paper, we propose a hierarchical tracking system using modular Bayesian networks and a naive Bayes classifier. The Bayesian networks can respond flexibly in uncertain situations and can be designed by domain knowledge even when the data are not enough. Bayesian network modules infer the weather states which are classified into nine classes. Then, naive Bayes classifier selects the most effective method considering inferred weather states and the system makes a decision using the rules. We collected real weather data for the experiments and the average accuracy of the proposed method is 93.9%. In addition, comparing the photovoltaic efficiency with the pinhole camera system results in improved performance of about 16.58%.

• Journal of Advanced Navigation Technology
• /
• v.21 no.1
• /
• pp.99-106
• /
• 2017

In this paper, an energy harvesting and profiling system is designed for smart video devices in internet of things environments without dedicated power source. The energy harvesting module provides the harvested energy from solar panel to the smart video device. The energy profiling module measures the battery outflow current and the battery voltage of the smart video device and the consumed energy of processes, and calculate the harvested energy from the energy harvesting module to the smart video device and the total energy consumption of the smart video device. The accuracy of the harvested energy measured by the device energy profiling module is validated by comparing with the calculated energy using the regional solar radiation provided by Korea Meteorological Administration. Energy harvesting data from the designed energy harvesting and profiling system can be used to design the perpetual operation of smart video devices or Internet of Things sensors.

• Journal of the Korean Solar Energy Society
• /
• v.27 no.4
• /
• pp.105-111
• /
• 2007

Hybrid PV/Thermal systems consisting of photovoltaic module and thermal collector can produce the electricity and thermal energy. The solar radiation increases the temperature of PV modules, resulting in the decrease of their electrical efficiency. Accordingly hot air can be extracted from the space between the PV panel and roof, so the efficiency of the PV module increases. The extracted thermal energy can be used in several ways, increasing the total energy output of the system. This study describes a basic type of PV/T collector using water. In order to analyze the performance of the collector, the experiment was conducted. The result showed that the thermal efficiency was 17% average and the electrical efficiency of the PV module was about $10.2%{\sim}11.5%$, both depending on solar radiation, inlet water temperature and ambient temperature.