• KIEAE Journal
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• v.4 no.2
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• pp.65-72
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• 2004

Ecological architecture enables people to recycle and reuse architectural resources within the category of ecosystem and also to minimize the effect on environment in a whole process, including architectural planning, usage and exhaustion to use sustainable energies. Rammed earth wall construction method utilized in EcoCenter located in Crystalwaters ecological village in Austrailia is a good example, which maximizes its advantages and also covers its limits to use soil and wood as structural resources. In a case of wood, they used non-treated timber to minimize environmental load and utilized used materials in openings. In the roofs, aluminum coated steel which is plated with zinc collects rain effectively even though it is not regenerable. Nontoxic finishes and insulation in floor and ceiling with used papers are able to minimize its environmental load. Solar energy system applied in EcoCenter enables them to market extra energy with electricity companies as well as support needs of its own buildings to utilize photovoltaic panel system with PV panels. Passive solar system is planned effectively in heating and cooling to apply regenerative walls in a use of rammed earth wall construction and natural ventilation systems through openings.

• Journal of the Korean Solar Energy Society
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• v.30 no.2
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• pp.10-15
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• 2010

The experimental study was conducted to optimize the system dissipating properly heat from the in-situ solar panel installed on the roof. For this purpose, six 12-Watt panels, which were consisted of the different design conditions such as containing phase change material(PCM), changing the array of the aluminum fin and honeycomb at the back of the panel, were tested. PCM, which had $44^{\circ}C$ melting point, was chosen in this study. In order to enhance absorbing and expelling heatin PCM, profiled aluminum fin was placed either inward oroutward from the panel. Furthermore, Aluminum honeycomb is imbedded in the back container to find if it would improve the thermal conductivity of PCM. During the experiment, there were ranged to $26^{\circ}C\sim32^{\circ}C$ for outdoor temperature and $700W/m^2\sim1000W/m^2$ for irradiance. As a result, the solar panel, combined with honeycomb and outward fins with PCM instead of placing the fins inward, is showing the best performance in terms of controling panel temperature and its efficiency.

• Journal of the Korean Solar Energy Society
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• v.38 no.6
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• pp.37-49
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• 2018

In this paper a new kind of unit-prefabricated building is shown. The unit-prefabricated buildings are made up living unit, energy unit, water unit. The design trend implemented the energy insulation, solar PV panels, energy storage system which are maintained for zero energy buildings. We made a prototype for zero energy flexible residential unit. The first step, we was evaluated the physical performance, insulation, airtightness. The second step, we was evaluated energy performance building to design heating and cooling system to combined PV system. As a results, the insulation performance wall was $0.18W/(m^2{\cdot}K)$. The results of air-tightness was 12.13 ACH@50 (1/h). The building energy demand ratings and solar energy generation has the possible to be ballanced.

• Journal of Power Electronics
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• v.19 no.1
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• pp.220-233
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• 2019

This work aims to study and analyze the various operating modes of universal power converter which is powered by solar and thermoelectric generators. The proposed converter is operated in a DC-DC (buck or boost mode) and DC-AC (single phase) inverter with high efficiency. DC power sources, such as solar photovoltaic (SPV) panels, thermoelectric generators (TEGs), and Li-ion battery, are selected as input to the proposed converter according to the nominal output voltage available/generated by these sources. The mode of selection and output power regulation are achieved via control of the metal-oxide semiconductor field-effect transistor (MOSFET) switches in the converter through the modified stepped perturb and observe (MSPO) algorithm. The MSPO duty cycle control algorithm effectively converts the unregulated DC power from the SPV/TEG into regulated DC for storing energy in a Li-ion battery or directly driving a DC load. In this work, the proposed power sources and converter are mathematically modelled using the Scilab-Xcos Simulink tool. The hardware prototype is designed for 200 W rating with a dsPIC30F4011 digital controller. The various output parameters, such as voltage ripple, current ripple, switching losses, and converter efficiency, are analyzed, and the proposed converter with a control circuit operates the converter closely at 97% efficiency.

• Journal of the Korean Society of Industry Convergence
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• v.26 no.6_1
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• pp.967-976
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• 2023

Currently, with the thriving development in the field of solar energy, the widespread adoption of solar grid-connected power conversion systems is rapidly expanding. As the market continues to grow, the efficiency of solar power conversion systems is steadily increasing, while prices are rapidly decreasing. Photovoltaic panels often produce low output voltages, and Boost converters are commonly employed to elevate and stabilize these voltages. They are also utilized for implementing Maximum Power Point Tracking (MPPT), ensuring the full utilization of solar power generation. Recently, synchronous control techniques have been introduced, using controllable switching devices like Si IGBT or SiC MOSFET to replace the diodes in the original circuits. However, this has raised concerns related to costs. This paper offers a compromise solution, considering both the performance and economic factors of the converter. It proposes a hybrid high-efficiency synchronous converter structure that combines Si IGBT and SiC MOSFET. Additionally, the proposed topology has been practically implemented and tested, with results confirming its feasibility and cost-effectiveness.

• Solar Energy
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• v.10 no.3
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• pp.13-18
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• 1990

When nonuniform thermal boundary conditions are imposed on the surface of a circular cylinder in crossflow, the heat transfer characteristics can be quite different compared to what is found for isothermal or constant heat flux boundary conditions. In the present analysis, two kinds of nonuniform boundary conditions along the circumference of the cylinder are considered in a uniform stream of air: step changes and linear profiles. Step changes in temperature can arise on the surface of an external, cylindrical, solar central receiver. As the working fluid(water) flows through the vertical tubes that ring the circumference of Solar One(a solar central receiver in Barstow, California), the solar flux on the receiver heats the water from a liquid to a superheated state. In this process, portions of the receiver panels, and thus portions of the circumference of the cylinder, function as a preheater, boiler, or superheater. Hence the surface temperature can vary significantly around the cylinder. Common engineering practice has been to use an average wall temperature with an isothermal cylinder heat transfer coefficient when estimating the convective loss in these kinds of situations.

• Journal of IKEEE
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• v.24 no.2
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• pp.392-402
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• 2020

This paper proposes a solar tracking system without photo-sensors. The system can be classified into four modules: Solar Tracking, MPPT, ESS, and Real-Time Monitoring. Nine solar panels, as a basic unit, are adopted with grid structures of different heights to reduce wind influence and to enable solar tracking without photo-sensors. The low-cost MCU implements MPPT method which generates PWM switching signal for boost converter. The unit of ESS consists of three-series and four-parallel lithium-ion batteries in order to enable monitoring for abnormalities in temperature and electrical characteristics of battery. Four MCUs used in the system consists of two AVR Atmega128, and two Raspberry PI, and they exchanges operation informations. Experimental results of the proposed system show the solar tracking performance, the possibility of on-site and remote monitoring and the convenience of maintenance based on IoT technology.

• Journal of IKEEE
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• v.22 no.3
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• pp.664-671
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• 2018

Generally, conventional solar tracking systems employ irradiance sensors to track a sun position, which enables the system to generate maximum solar energy. The usage of irradiance sensors increases system costs and deteriorates the performance of systems from sensor malfunctions. In this paper, a new solar tracking system without irradiance sensors has been proposed in which the controller capable of controlling and monitoring remotely is based on Artik platform. The proposed system tracks the sun position by comparing the amount of currents from several solar panels, resulting in removing irradiance sensors. In order to verify the performance of the proposed solar tracking method, the 12[V]-20[W] prototype system is built and implemented. Since the proposed system has remote monitoring functions through the employment of Artik as the IoT platform, more advantages in installation, maintenance and expanded functionality can be obtained compared to the conventional solar tracking system.

• Proceedings of the KIPE Conference
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• 2015.07a
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• pp.103-104
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• 2015

Solar energy has proven to be a potential clean energy source to help offset the large consumption of fossil. Nowadays, many research projects aim to enhance photovoltaic (PV) system performance and functionality. This research focuses on integrating self-monitor capability into dc-dc converters that control PV panels to detect a fault in series-connected PV cells, called hot spotting. A detection method using ac parameter characterization is proposed and its operation is examined through simulation.

• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.52-54
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• 2000

In PV power generation system study, huge system apparatuses are needed in order to verify the effect of system efficiency and stability considering the size of solar panels, the sort of converter types, and the load conditions and so on. And also, under the same weather and load conditions it is impossible to compare a certain MPPT control scheme to others. In this paper, in order to obtain effective solutions for the above mentioned topics, the solar cell array is simulated with it's VI characteristic equations, and the real field data of weather conditions is interfaced to EMTDC using Fortran program interface method. Consequently the simulation of PV power generation system using field data is realized in this paper, and acceptable results, which show close match between the real data of PV panel and the simulated data, were obtained.