• Proceedings of the KIPE Conference
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• 2003.07a
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• pp.204-207
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• 2003

PV model is presented based on the shockley diode equation. The simple model has a photo-current source, an single diode junction and a series resistance and includes temperature dependences. An accurate PV module electrical model is presented, matching with boost converter MPPT strategy and demonstrated in Matlab for a typical general purpose solar cell. Given solar insolation and temperature, the model returns current vector and MPP.

• Journal of the Microelectronics and Packaging Society
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• v.7 no.3
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• pp.1-6
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• 2000

A simple and compact type of thermoelectric generator was developed as the energy saving system using waste hot water and low temperature waste heat sources. Sixteen of Bi-Te thermoelectric modules were packaged in series for thermoelectric conversion system using hot water as heat source. The thermoelectric generator shows the power output of about 4.5 W with the temperature difference of about 75 K at 40 $\Omega$ and 0.35 A for the electrical resistance and current of the used thermoelectric module, respectively.

• Journal of the Korean Solar Energy Society
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• v.30 no.6
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• pp.16-21
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• 2010

It is well-known that Boron-doped Cz Si solar cells suffer light-induced degradation due to boron-oxygen defect which is responsible of a reduction in lifetime and hence efficiency. In this paper, we assume that PV solar cell has been connected with variable load to account the real operating condition and it shows different light-induced degradation of Si solar cell. To evaluate the effect of light-induced degradation for solar cell with various load, Single crystalline solar cells are connected with open and short circuits during light exposure. Isc-Voc curve evaluate light induced degradation of solar cells and the reason is explained as a change for serial resistance. From the results, Electrical characteristics of solar cells show better performance under short circuit conditions, after light exposure.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.9 no.6
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• pp.41-48
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• 1995

In field oriented control of Induction motors, speed sensor is required, which reduces the sturdiness of drive system and together with the expenditure of hardware for faultless transmission and processing of sensor signals it causes considerable expenses. These expensive sensors can be replaced by speed sensorless concept. And for good control, the knowledge of the rotor flux component or the rotor resistance are needs. Thus, this paper is based on a Extended Kalman Filter (EKF) that estimates the state variables that are required for the control by only measuring the line voltages and currents of the machine. the rotor time constant and speed estimated by the EKF show satisfactory agreement with the real values, with the simulation approaches.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.5
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• pp.862-867
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• 2016

In this study, the embroidery textile conductive wire of conductive yarn was designed into the wearable integrated clothing for sensing the infant's body temperature. To develop a high quality of the stable fiber-based textile conductive wire, firstly the five types of conductive yarns were twisted or covering polyester yarns and the coated conductive fiber with silver(Ag) or iron(Fe). As a result of comparative conductivity in conductive yarns of yarn processing, the 250 denier of conductive yarns with $0.74{\Omega}$/1~5cm were proposed and used for the integrated embroidery textile conductive wire for sensing. During experiments using the proposed embroidery textile conductive wire, measured resistance of thermistor according to the body temperature was correctly delivered to amplifier module, and showed feasible reliability of temperature sensing. As a wearable application, conductive yarns which takes forms of embroidery textile conductive wire would seems to be reliable as a conductive wire and could be replaced by the conductive metal wires.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.487-488
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• 2006

As DLC coating possesses such features as, high hardness, high elasticity, abrasion resistance and chemical stability, there have been exerted continuous efforts in research works in a variety of fields, and this technology has also been applied widely to industrial areas. In this research work, the optimal grinding condition was identified using Microlens Process Machine in order to contribute to the development of aspheric glass which is to be used for mobile phone module having 2 megapixel and $2.5{\times}$ zoom, and mold core (WC) was manufactured having performed ultra-precision machining and effects of DLC coating on shape accuracy(P-V) of mold core and surface roughness(Ra) as well were measured and evaluated.

• Journal of the Korean Society of Industry Convergence
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• v.23 no.6_2
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• pp.989-998
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• 2020

Recently, demands for large-capacity electronic loads are increasing in various industries such as a reliability test for the performance of a DC power supply device or a dummy-load for improving the stability of an independent microgrid to be actively built in the future. The electronic load required in these various fields requires an operation such as a continuously variable resistance load while minimizing the switching harmonic component generated in the electric load current in order to reduce the influence of interference from the load peripheral device. Electronic loads require a system that minimizes switching current ripple for load control. Therefore, in this paper, we propose a three-level module converter structure to reduce the current ripple of an electronic load, and a multilevel interleaved power converter topology to reduce the current ripple. The validity of the proposed electronic load, 3-level 6 interleaver converter, was verified by simulation and experiment. In addition, the user's convenience was provided by applying the emotional command curve interface method.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.89-93
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• 2018

Ceramic substrates applied to power modules of electric vehicles are required to have properties of high thermal conductivity, high electrical insulation, low thermal expansion coefficient and resistance to abrupt temperature change due to high power applied by driving power. Aluminum nitride and silicon nitride, which are applied to heat dissipation, are considered as materials meeting their needs. Therefore, in this paper, the properties of aluminum nitride and silicon nitride as radiator plate materials were compared through a commercial analysis program. As a result, when the process of applying heat of the same condition to aluminum nitride was implemented by simulation, the silicon nitride exhibited superior impact resistance and stress resistance due to less stress and warping. In terms of thermal conductivity, aluminum nitride has superior properties as a heat dissipation material, but silicon nitride is more dominant in terms of reliability.

• Korean Journal of Materials Research
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• v.29 no.1
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• pp.37-42
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• 2019

This study investigates Ag coated $Cu_2O$ nanoparticles that are produced with a changing molar ratio of Ag and $Cu_2O$. The results of XRD analysis reveal that each nanoparticle has a diffraction pattern peculiar to Ag and $Cu_2O$ determination, and SEM image analysis confirms that Ag is partially coated on the surface of $Cu_2O$ nanoparticles. The conductive paste with Ag coated $Cu_2O$ nanoparticles approaches the specific resistance of $6.4{\Omega}{\cdot}cm$ for silver paste(SP) as $(Ag)/(Cu_2O)$ the molar ratio increases. The paste(containing 70 % content and average a 100 nm particle size for the silver nanoparticles) for commercial use for mounting with a fine line width of $100{\mu}m$ or less has a surface resistance of 5 to $20{\mu}{\Omega}{\cdot}cm$, while in this research an Ag coated $Cu_2O$ paste has a larger surface resistance, which is disadvantageous. Its performance deteriorates as a material required for application of a fine line width electrode for a touch panel. A touch panel module that utilizes a nano imprinting technique of $10{\mu}m$ or less is expected to be used as an electrode material for electric and electronic parts where large precision(mounting with fine line width) is not required.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.5
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• pp.362-368
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• 2014

Fiber optic sensors (FOS) have advantages such as electromagnetic interference (EMI) immunity, corrosion resistance and multiplexing capability. For these reasons, they are widely used in various condition monitoring systems (CMS). This study investigated a muscular condition monitoring system using fiber optic sensors (FOS). Generally, sensors for monitoring the condition of the human body are based on electro-magnetic devices. However, such an electrical system has several weaknesses, including the potential for electro-magnetic interference and distortion. Fiber Bragg grating (FBG) sensors overcome these weaknesses, along with simplifying the devices and increasing user convenience. To measure the level of muscle contraction and relaxation, which indicates the musle condition, a belt-shaped FBG sensor module that makes it possible to monitor the movement of muscles in the radial and circumferential directions was fabricated in this study. In addition, a uniaxial tensile test was carried out in order to evaluate the applicability of this FBG sensor module. Based on the experimental results, a relationship was observed between the tensile stress and Bragg wavelength of the FBG sensors, which revealed the possibility of fabricating a muscular condition monitoring system based on FBG sensors.