• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.103-106
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• 2002

This paper has studied a remote AMR(Automatic Meter Reading) system using the power line and the telephone line as a communication media and the digital power meter. In the developed system, because we have used the power line and telephone, the facility is very easy and then its cost is not expensive. The system includes following elements: a digital power meter, an indoor communication system using a power line modem and a telephone line interface system for sending data to the utility company.

• Journal of Industrial Technology
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• v.18
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• pp.431-437
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• 1998

In this paper, we presented a modeling of the power line channel and a new digital communication system over the channel. Firstly, we proposed a new tranceiver structure with DS-CDMA spread spectrum technique and convolutional coder and block interleaver against severe noisy power line environment. Also, QPSK modulation technique was used to get bandwidth efficiency. And then we performed a simulative evaluation of the system using MATLAB communication/simulink toolbox. According to the simulation results, the proposed system gives $10^{-6}$ BER at 20dB SNR.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.2
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• pp.105-114
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• 2015

Heated glasses are widely used to prevent surface condensation and freezing in ship and building windows. This study proposes a heated glass temperature control system composed of power and control circuits to control the temperature of heated glasses. The proposed temperature control system adopts a digital controller instead of a conventional analog controller. Thus, the proposed system has better characteristics, such as precise setup and control of glass temperature, setup and control of output power, and control mode change between ON/OFF and phase controls. The system can also implement multi-functional control algorithms. The control characteristics are not dependent upon external disturbances, such as ambient temperature and electrical noises. Furthermore, the proposed temperature control system utilizes the power line communication (PLC) method to control the number of heated glasses without any extra communication lines. The system proposes a new communication protocol with strong immunity to electrical switching noises. A new sensorless algorithm is used to detect the temperature of the heated glass. This study presents the design guidelines in detail and its effectiveness are confirmed by implementing a 4-kw prototype temperature control system.

• Proceedings of the KIPE Conference
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• 2007.07a
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• pp.500-502
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• 2007

In case Power Line Communication (PLC) method is applied to a rainwater monitoring system, PLC module should be utilized. In this paper, PLC module using ST7538Q is implemented. The design rules of the IC peripheral circuit are explained in detail. The operation of the implemented PLC module is verified through the experimental results.

• The Journal of the Korea institute of electronic communication sciences
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• v.12 no.6
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• pp.1035-1042
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• 2017

In this paper, we implement a public address system using power line communication in order to operate, extend, and expand the complicated public address devices and cables easily. Power line communication based public address system implemented consists of a public address control board and public address speaker boards which are suitable to digital streaming modulation. It can be noticed that we met satisfied results from performance measurement such as maximum audio output, audio channel response time, audio output SNR, and audio output THD+N.

• The Transactions of the Korean Institute of Electrical Engineers P
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• v.64 no.4
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• pp.291-296
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• 2015

Transmission line is exposed to a large area, and then faults are likely to occur than the other component of power system. When a fault occurs on a transmission line, fault locator helps fast recovery of power supply on power system. This paper deals with the design of a digital fault locator for improvement accuracy of the fault distance estimation and a fault occurrence position for transmission line. The algorithm of a fault locator uses a DC offset removal filter and DFT filter. The algorithm utilizes a fault data of GPS time synchronized. The computed fault information is transmitted to the other side substation through communication. The digital fault locator includes MPU module, ADPU module, SIU module, and a power module. The MMI firmware and software of the fault locator was implemented.

• Journal of Navigation and Port Research
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• v.26 no.3
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• pp.295-302
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• 2002

Currently digital communication system adapt various digital modulation schemes. All these communication systems are required to cause the minimum interference to adjacent channels, they must therefore employ the linear power amplifiers. In respect to linear power amplifiers, there are many linearization techniques. Feedforward power amplifier represent very wide bandwidth and high linearization capability. In the feedforward systems overall efficiency is reduced due to the loss of delay line. In this paper, delay filter instead of transmission delay line adapted to get more high efficiency. Experimental results showed that ACLR has improved 17.04dB which is added 2.54dB by using the delay filter.

• Journal of Advanced Marine Engineering and Technology
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• v.31 no.2
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• pp.182-189
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• 2007

This paper describes the implementation of control and monitoring system of ship's lamps at local area using power line communication method, power line modem(PLM). We design modem, microprocessor interface for electric power control by frequency control and analog to digital signal conversion, lamp device. PLM communication is very economical using existing electric power line unlike RS-232, RS-485 communications. We verify and confirm by experimental work that control and monitor lamp system for ship by an PLM communication.

• The Journal of the Korea institute of electronic communication sciences
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• v.17 no.6
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• pp.1113-1120
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• 2022

In this paper, a communication methodology for the digital FRTU(: Feeder Remote Terminal Unit) required by the smart grid distribution system was studied. The digital FRTU consists of a fault handling unit and a communication unit. The fault handling unit transmits fault information to the communication unit in case of a failure, and the communication unit is designed to autonomously determine the fault section through two-way communication between surrounding digital FRTUs. For performance verification, a performance verification system consisting of 3 line sections based on 3 digital FRTUs was constructed to enable fault simulation for various failure scenarios. Various fault cases including one phase ground fault, line-to-line short-circuit fault, and three-phase short-circuit fault were experimentally simulated on the established performance verification system, and the validity of the developed methodology was confirmed by proving the accurate fault section inference results for each fault simulation case.

• Journal of Korea Society of Digital Industry and Information Management
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• v.15 no.4
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• pp.9-17
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• 2019

Sun power generation systems which use large capacity centralized inverters have loss of power generation due to cloud and building shadows, pollution, cell deterioration, etc. To minimize loss of power generation, decentralized solar power systems using multiple micro-inverters are being proposed as an alternative. A distributed solar power system consisting of a system-connected system uses power line communication to collect data from the micro-inverters. Power line communication has the advantage of using power lines without separate lines for data transmission, but in distributed solar power generation systems that use a large number of micro-inverters, the bit error rate is less reliable due to the phenomenon caused by limited transmission power, high load interference and noise, variable signal attenuation, and impedance characteristics. So we proposed wireless intelligent controller for micro-inverter that is used to build distributed solar power systems. and we design and implement that. Further, the proposed wireless intelligent controller for micro-inverter was used to establish a small-volume solar power plant to check its function and operation.