• Journal of Power Electronics
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• v.7 no.2
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• pp.159-173
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• 2007

In this paper, an intelligent sliding-mode position controller (ISMC) for achieving favorable decoupling control and high precision position tracking performance of permanent-magnet synchronous motor (PMSM) servo drives is proposed. The intelligent position controller consists of a sliding-mode position controller (SMC) in the position feed-back loop in addition to an on-line trained fuzzy-neural-network model-following controller (FNNMFC) in the feedforward loop. The intelligent position controller combines the merits of the SMC with robust characteristics and the FNNMFC with on-line learning ability for periodic command tracking of a PMSM servo drive. The theoretical analyses of the sliding-mode position controller are described with a second order switching surface (PID) which is insensitive to parameter uncertainties and external load disturbances. To realize high dynamic performance in disturbance rejection and tracking characteristics, an on-line trained FNNMFC is proposed. The connective weights and membership functions of the FNNMFC are trained on-line according to the model-following error between the outputs of the reference model and the PMSM servo drive system. The FNNMFC generates an adaptive control signal which is added to the SMC output to attain robust model-following characteristics under different operating conditions regardless of parameter uncertainties and load disturbances. A computer simulation is developed to demonstrate the effectiveness of the proposed intelligent sliding mode position controller. The results confirm that the proposed ISMC grants robust performance and precise response to the reference model regardless of load disturbances and PMSM parameter uncertainties.

• Proceedings of the KIPE Conference
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• 2003.11a
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• pp.238-243
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• 2003

The solar cells should be operated at the maximum power point because its output characteristics are greatly fluctuated on the variation of insolation, temperature and load. The output power of solar cell is DC, therefore it is necessary to install an inverter among electric power converts. The inverter have to supply a sinusoidal current and voltage to the load and the interactive utility line. In the paper, the proposes a photovoltaic system designed with a step up chopper and single phase PWM voltage source inverter. Synchronous signal and control signal was processed by microprocessor for stable modulation. The step up chopper operates in continuous mode by adjusting the duty ratio so that the photovoltaic system tracks the maximum power point of solar cell without any influence on the variation of insolation and temperature because solar cell has typical dropping character. The single phase PWM voltage source inverter consists of complex type of electric power converter to compensate for the defect, that is, solar cell cannot be developed continuously by connecting with the source of electric power, from 10 to $20\%$. The single phase PWM voltage source inverter operates in situation that its output voltage is in same phase with the utility voltage. The inverter supplies an ac power with high factor and low level of harmonics to the load and the utility power system.

• Proceedings of the Korea Institute of Convergence Signal Processing
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• 2005.11a
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• pp.373-376
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• 2005

본 논문에서는 이와 같은 요청에 부합되는 강인한 처지제어기를 얻고자, 다층 신경회로망을 이용하여 퍼지제어기 멤버쉽 함수의 전건부 및 후건부 파라미터들을 시스템에 알맞게 자기 조정하기 위해 최급구배법(Steepest Gradient Method)에 근거한 오차 역전파 알고리즘으로 적응 학습시킬 수 있는 뉴로-퍼지제어기 (Neuro-Fuzzy Control : NFC)의 구조 및 알고리즘을 제안하였다.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.530-533
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• 2001

Interleaved Dual Boost(IDB) converter can reduce current ripple, switching loss and harmonics without filter in input power line. Moreover, this improve power factor. In this paper, we will use the state average methode and small signal analysis at the Interleaved dual boost converter. 4-type controllers were designed by using control transfer function. The result of these controller simulations is analyzed and proposed a proper controller at IDB

• Proceedings of the KIEE Conference
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• summer
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• pp.289-291
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• 2004

ln this paper, A dc-offset elimination novel algorithm based on an An model is proposed. The algorithm can eliminate dc-offset rapidly than other algorithms. The signal of fault current can be presented as a linear equation combined sinusoidal with exponential signals. Then, the linear equation can be presented an auto-regressive(AR) model and do-offset can be calculated by the equation of AR model. So it is possible to be removed the dc-offset from the original current signal. Performance evaluation of the algorithm was tested on condition that A-phase ground fault on 154kV 25km overhead transmission line.

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.3
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• pp.275-281
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• 2016

A novel bidirectional magnetic wireless communication system is proposed in this study. This system provides the communication capability between the source and load sides by high-frequency signal while wireless power is transferred. Contrary to the conventional wireless communication systems using complex IC circuit and active components, the proposed system is simply composed of passive components. It is practical and beneficial for environmental robustness, cost effectiveness, and simple implementation. The detailed static analysis of the proposed system for power and communication lines is established. The proposed system is experimentally verified, and results show that a 0.1 voltage gain for communication line is obtained while a 2.0 voltage gain for the power line is achieved. The proposed system is adequate for practical applications as it allows the inductive power transfer system to wirelessly and easily communicate between the source and load sides.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.3 no.1
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• pp.19-23
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• 2010

This study is to develop power line communication and short-range wireless communication system using LED. I will create optical receiver and transmitter using LED and optical sensor and connectors for display device and communication in receiver and transmitter were created. Experiment method is to signal and waveform through oscilloscope date from optical sensor after chosen a highly efficient LED. In addition, reception and transmitter of smoothly data using visible light communication program were checked. I will compliment problems through this experiment and constantly study, improve on power loss.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.19 no.11
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• pp.1281-1286
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• 2008

The PSK carrier signal recovery circuit using a six-port phase correlator was analyzed and the circuit structure is proposed in this paper. The proposed carrier signal recovery circuit that is made of reflection element and six-port phase correlator, which is comprised of a power divider and three hybrid branch line couplers, give a simple structure and can be fabricated without no difficulty. The circuit recovers the carrier signal of BPSK and QPSK modulation signal. The proposed scheme can be utilized as a basis structure for high-mode PSK carrier signal recovery. By simulation results, the recovered signal by the proposed circuit shows a good carrier signal characteristic with CW signal of a constant phase($23.4^{\circ}$) and ${\pm}0.8^{\circ}$ phase error due to glitch conditions.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.376-378
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• 1996

This paper presents a new PFC control method which replaces a fast line current measurement with a filtered load current measurement. Using the power balance relation between the input and the output of the boost converter. the input current can be described as the function of load current. Thus the PWM signal which effects the switching control of the boost converter is generated using the PFC input voltage, the PFC output voltage and the load current as input variables. By using a filter between the bridge rectifier and a dc-to-dc converter, the input voltage of the dc-to-dc converter is forced to always maintain above zero volt. Then the input current traces a sinewave in phase. The proposed scheme accomplishes a very high power factor and a low harmonic distortion of the line current. The validity of this scheme is demonstrated through simulation.

• Proceedings of the KIEE Conference
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• 1999.07c
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• pp.1152-1154
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• 1999

Recently. due to the drastic development of communication method between substations for pilot protective relaying system. The power line carrier(PLC) application is getting obsolete. Consequently, the coupling capacitor voltage transformer (CCVT) loses its necessity for the carrier coupling function, and so wound voltage transformer(VT) can be used to substitute CCVT for voltage signal. However, VT has been reported to give rise to ferro-resonance phenomena, so sufficient consideration on applying the VT to line side is required. This study introduces probable technical problems in using the VT on T/L side, and carries out feasibility study on the basis of modeling results by EMTP(Electro-magnetic transient program)