• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.58-62
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• 2002

The MPPT methods is used to get the maximum energy from the limited size of a photovoltaic array. This study deals with the suitable MPPT method of solar lighting lamp and the improved charge and discharge characteristics. So we proposed the control algorithm for stand-alone photovoltaic array(SPVS). The result of experiment is presented the improved charge characteristics and the charge and discharge times reduction, the depth of discharge control. so, the system stabilization goes up. It is possible economical effect to apply for solar lighting lamp used photovoltaic array

• Proceedings of the KIPE Conference
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• 1998.10a
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• pp.982-986
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• 1998

The peak-power-tracking solar array regulator sensing the inductor current is proposed. Since it uses the inductor current as the solar array output power information, the PPT control scheme can be greatly simplified. The charge controlled two-loop scheme is presented to improve the dynamics due to the inductor current sensing. The comparison between the single-voltage loop controlled system and the two-loop controlled system employing the charge control is presented. This paper also contains the simulation results of that comparison.

• Proceedings of the KIEE Conference
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• 2001.07e
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• pp.116-119
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• 2001

In this research, we detect the charge state within $0.1{\sim}0.3[A]$ and develop the intelligent digital charge device by applying a fine pulse signal using PWM inverter and Proportional-Integral(PI) controller which uses micro -processor and intelligent technique. The ripple rate is within ${\pm}1%$, and the indicator error rate of full charge state is within ${\pm}1%$, and the voltage stability is within ${\pm}0.1[V]$, and the accuracy of voltage detect is 48[V] and ${\pm}0.5[V]$ in the reference of 100[A].

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.910-914
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• 2005

In this paper an optimal method based on fuzzy logic for controlling parallel hybrid electric vehicles is presented. In parallel hybrid electric vehicles the required torque for deriving and operating the on-board accessories is generated by a combination of internal-combustion engine and an electric motor. The powersharing between the internal combustion engine and the electric motor is the key point for efficient driving. This is a highly nonlinear and time varying plant and its control strategy will be implemented with the use of fuzzy logic controller. The fuzzy logic controller will be designed based on the state of charge of batteries and the desired torque for driving. The output of controller controls the throttle of the combustion engine. The main contribution of this paper is the development of an optimal control based on fuzzy logic, which maximizes the output torque of the vehicle while minimizing fuel consumed by the combustion engine.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.49 no.4
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• pp.282-290
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• 2000

In this paper, the charge control with the input voltage feedback is proposed for the input series-output series-output parallel connected converter configuration for the high speed train power system application. This control scheme accomplishes the output current sharing for the output-parallel connected modules as well as the input voltage sharing for the input series connected modules for all operating conditions including the transients. It also offers the robustness for the input voltage sharing control according to the component value mismatches among the modules. And this configuration enables the usage of MOSFET for a high voltage system allowing a higher switching frequency for lighter system weight and smaller size. The performance of the proposed scheme is verified through the experimental results.

• Journal of the Korean Solar Energy Society
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• v.33 no.5
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• pp.69-75
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• 2013

To increase the efficiency of the photovoltaic, almost photovoltaic appliances are controlled by Maximum Power Point Tracking(MPPT). Existing most of the PV MPPT techniques have used power which multiplies sensed output current and voltage of the solar cell. However, these algorithms are unnecessarily complicated and too expensive for small and compact system. The other hand, the proposed MPPT technique is only one sensing of the MPPT converter's output current, so there is no need to insert another sensors of battery side. Therefore, this algorithm is simpler compared to the traditional approach and is suitable for low power solar system. Further, the novel proper charge/discharge algorithm for the battery with PV MPPT is developed. In this algorithm, there is CC battery charge mode and load discharge mode of the PV cell & battery dual. Also we design current control to regulate allowable current during the battery charging. The proposed algorithm will be applicable to battery included solar cell applications like solar lantern and solar remote control car. Finally, the proposed method has been verified with computer simulation.

• Journal of Preventive Medicine and Public Health
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• v.40 no.3
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• pp.205-212
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• 2007

Objectives : The purpose of this study was to identify the factors influencing the intention to have stomach cancer screening using the theory of planned behavior (TPB) in Korea. Methods : For this population-based study, 1,535 adult respondents (aged 40 to 70 years) were recruited using multi-stratified random sampling and a face-to-face administered questionnaire. This study was based on Ajzen's theory of planned behavior. Intentions were divided into three scenarios for fee payment in the next two years : (1) free of charge, (2) co-payment, and (3) full charge. Multiple linear regression was used to identify the factors influencing the intention to have stomach cancer screening. Results : Perceived behavioral control and attitude toward stomach cancer screening were significant predictors of the intention to have stomach cancer screening. However, subjective norm only influenced the intention to have stomach cancer screening with full charge in the next two years. Conclusions : The results suggest that attitude and perceived behavioral control are likely to contribute toward increasing the intention to have stomach cancer screening. Especially, perceived behavioral control is a good predictor. Because the study subjects were nation wide residents, the study results can be generalized.

• Proceedings of the Korean Geotechical Society Conference
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• 1999.10a
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• pp.209-216
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• 1999

In tunneling and road cuts by blasting, it is of the utmost importance that the remaining rock is of high quality in order to avoid rockfall, rockslides and excessive maintenance work. Therefore, numerous blasting techniques which make use of decoupled charge or shock wave superposition effect have been used to control overbrake. In this paper. some approximate method for the determination of blast load according to the charge condition was introduced at first and, instrumented tests were conducted in small scale transparent material to investigate the shape and amplitude of blast load around the bore hole. Compare to the fully coupled charge, low amplitude of blast load around the bore hole was observed in the decoupled charge and explosion gas pressure was important in the shape of blast load. Therefore, quasi-static behaviour of the crack pattern was shown due to low loading rate.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.647-652
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• 2015

A fully coupled finite element analysis (FEA) technique was developed for analyzing the discharge phenomena and dielectric liquid flow while considering surface charge density effects in dielectric flow guidance. In addition, the simulated speed of surface charge propagation was compared and verified with the experimental results shown in the literature. Recently, electrohydrodynamics (EHD) techniques have been widely applied to enhance the cooling performance of electromagnetic systems by utilizing gaseous or liquid media. The main advantage of EHD techniques is the non-contact and low-noise nature of smart control using an electric field. In some cases, flow can be achieved using only a main electric field source. The driving sources in EHD flow are ionization in the breakdown region and ionic dissociation in the sub-breakdown region. Dielectric guidance can be used to enhance the speed of discharge propagation and fluidic flow along the direction of the electric field. To analyze this EHD phenomenon, in this study, the fully coupled FEA was composed of Poisson's equation for an electric field, charge continuity equations in the form of the Nernst-Planck equation for ions, and the Navier-Stokes equation for an incompressible fluidic flow. To develop a generalized numerical technique for various EHD phenomena that considers fluidic flow effects including dielectric flow guidance, we examined the surface charge accumulation on a dielectric surface and ionization, dissociation, and recombination effects.

• Journal of Sensor Science and Technology
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• v.25 no.2
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• pp.155-159
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• 2016

In this work, we have developed a test system to examine whether the charge indicator of the plug-in hybrid electric vehicle (PHEV) works properly or not. In PHEV, the driver should charge the necessary electricity by plugging in manually and be able to know the charging status through the charge indicator conveniently located for the charging individual. Our system used the CAN bus to transmit the same commands from ECU to the indicator to test the proper operation of the indicator lights. It measured the electric current values during operation and analyzed to determine the quality of the indicators. The inspection items included the proper packaging, the electrical shorts, the LED lighting during charging, the LED lighting for charging failure, and the LED lighting when errors occur. We developed the system for the operators in the factory allowing them to approve the test results at the site. We developed the hardware, the control software, and the software to store the test results and the history of the products in the database. Serial numbers were given to the good quality products and the bar code labels were printed to trace the products afterwards. Through this work, we developed a system to inspect the electric parts in real time upon fabrication. We are planning to further improve our system to inspect the brightness of the indicator by adding the vision inspection in future.