• Journal of the Korea Academia-Industrial cooperation Society
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• v.3 no.4
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• pp.257-262
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• 2002

A design method of a power controller for controlling the temperature adopted in RTP (rapid thermal processing) which uses the phase control method is presented. The power controller is fabricated by using the design method presented in this paper and is tested. As the results, the range of average voltage from the variable output is 0∼198.06 V and the control resolution is 48.356 mV (12 bit) at the range of the input signal (0∼10 V).

• Proceedings of the KIEE Conference
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• 2005.05a
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• pp.239-242
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• 2005

A high speed address recovery technique for AC plasma display Panel(PDP) is proposed. By removing the GND switching operation, the recovery speed can be increased and switching loss due to GND switch also becomes to be reduced. The proposed method is able to perform load-adaptive operation by controlling the voltage level of energy recovery capacitor, which prevents increasing inefficient power consumption caused by circuit loss during recovery operation. Thus, the technique shows the minimum address power consumption according to various displayed images, different from Prior methods operating in fixed mode regardless of images. Test results with 50" HD single-scan PDP(resolution = 1366$\times$768) show that less than 350ns of recovery time is successfully accomplished and about 54% of the maximum power consumption can be reduced, tracing minimum power consumption curves.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.129-133
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• 2005

In this paper, first the thermodynamic model is presented to one of the super heaters and sprays of the Nekka power plant and then its unknown parameters are identified according to the registered data of the power plant. SCO control method is introduced to control the external steam temperature of super heater. Finally the conventional method in power plant for controlling external steam temperature of super heater is compared with new method and their performances are presented..

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.298-300
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• 2005

There are several types of communication method which is used for providing the supply of electric power stably. But the communication methods used in KEPCO have weak points in the viewpoint of economy, technology and management. Therefore the power plant located in the island could not be provided the communication service because of above reasons. Because the Satellite communication systems have competitive power in price and technology nowdays, the utility could provide the communication service in even back land. This paper presents some of design efforts for the satellite communication systems as the voice network in the island.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.63-66
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• 2002

This paper has been studied the parallel resonant inverter which controlling the constant power and tracking the load resonant frequency with PLL is possible, in order to minimize switching losses. The current-fed full-bridge type parallel resonant inverter of an induction heating system was composed of IGBT in switching device. For regulating the output power of an induction heating system, the Fuzzy controller is used. The Fuzzy controller makes the control signal for a stable power regulating control and when reference is changed, it is superior to adaptability. It has been evaluated a stable behavior for a noise with switching and a load disturbance.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2005.05a
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• pp.192-200
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• 2005

A high speed address recovery technique for AC plasma display panel(PDP) is proposed. By removing the GND switching operation, the recovery speed can be increased and switching loss due to GND switch also becomes to be reduced. The proposed method is able to perform load-adaptive operation by controlling the voltage level of energy recovery capacitor, which prevents increasing inefficient power consumption caused by circuit loss during recovery operation. Thus, th e technique shows the minimum address power consumption according to various displayed images, different from prior methods operating in fixed mode regardless of images. Test results with 50' HD single- scan PDP(resolution : $1366{\times}768$) show that less than 350ns of recovery time is successfully accomplished and about $54\%$ of the maximum power consumption can be reduced, tracing minimum power consumption curves.

• Journal of ILASS-Korea
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• v.23 no.1
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• pp.1-8
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• 2018

In this study, the effects of variation in cam phasing and valve lift of exhaust valves by using Cam-in-Cam system on combustion and emission characteristics for diesel engine were investigated under GT-POWER simulation environment. This paper showed analytic result of combustion characteristics and diesel exhaust valve's control with GT-Power 1-D detail model. As a result, it was found that volumetric efficiency and IMEP were decreased as the exhaust valve opening and closing timing is advanced due to its internal EGR effects. Also, it was found that NOx emission were decreased as EVC timing was retarded. These show that the retarding the exhaust valve closing and opening while keeping the duration at constant can be effective for controlling AFR and mixing rate in diffusion combustion of diesel engine.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.11
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• pp.113-122
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• 2011

This paper introduces and develops an efficient method for measuring power factor (PF) and its nature under nonlinear load current situations. The method is based on generating a pulse width modulated signal whose width correlates to the value of PF. This signal can then be employed as a feedback signal for controlling PF related power quantities in a system. This method has the advantages of its simple implementation, less computational complexity, and its allowable error of less than 4[%], which is justified by the computer simulation results.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.10a
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• pp.379-382
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• 2008

This paper gives the support method of DSM program(power load leveling for heating and cooling facilities on building). As the national power peak load increases recently, the peak load reduction is needed. So we studied about remote controlling of power load from heating/cooling facilities on building during peak times. To adopt new DSM program, it is very important to design DSM customer supporting system. So in this paper, we dealt with the result of customer survey, and the DSM potential regarding heating/cooling facilities on building. In conclusion, the peak reduction program of heating/cooling facilities is very important and the incentive of customer should be consist of two incentive types as an installation and power reduction.

• Proceedings of the KIEE Conference
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• 2007.10a
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• pp.63-64
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• 2007

In this paper, an adaptive passivity based excitation and governor control scheme is proposed to enhance the transient stability of a single machine infinite bus power system with parametric uncertainties. We employ a state model where the frequency, the difference between active and mechanical power, and the difference between the squared terminal voltage and its reference are regarded as state variables. Using this state model, the proposed controller is obtained in two steps; firstly, a simple direct adaptive passivation controller is designed for the power system with parametric uncertainties; then a linear PI controller is applied to guarantee the stability of the closed loop system.