• 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 Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.299-303
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• 2005

A lighting control switch, extended to incorporate a power line communication technology, is developed. The system uses not an exclusive microprocessor but a general one, and developed PPM protocol. The coupling circuit is a type of an isolation LC filter, and the impedance of the circuit was designed as low as possible to extend signal transmission distance. The frequency of the carrier, considering the data length and signal attenuation as the length of power lines, was set at 250 kHz. Tests on a prototype in an indoor power lines have shown that the switch has a stable operation with the distance of power lines

• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.127-128
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• 2006

The noise is major obstacle element in power line communication. However, because power supply networks are not designed for communication, there are various noise sources. Accordingly, a study of characteristic and cause of noise generated in low voltage transformer is important for outdoor power line communication. In this paper, we measure low voltage transformer noise in 1-30MHz using spectrum analyzer. We analyze cause and pattern of noise considering partial discharge.

• Journal of Satellite, Information and Communications
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• v.12 no.4
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• pp.146-151
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• 2017

This paper proposes a transmission algorithm that optimizes transmission power and sub-channel allocation to maximize energy efficiency considering characteristics of the channel impedance of power lines in power line communication systems. Since the received power at the receiver is influenced by the characteristics of the power line channel, it is necessary to consider channel characteristics when developing a transmission strategy in a power line communication systems. In addition, the energy efficiency should be optimized while meeting the practical constraints, such as the maximum transmission power limit of the transmitter and minimum quality of service for each user. In the computer simulation, we confirm that the energy efficiency of the proposed algorithm is improved compared to baseline schemes.

• The Journal of the Korea Contents Association
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• v.9 no.11
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• pp.37-45
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• 2009

Today, Internet service is a most important Information Source. So, the Power Line Communication has been achieved to offer Internet service to Last-Mile area. But, Power Line is not suitable for communication, So, electromagnetic wave is generated from Power Line during flow of communication information. And the electromagnetic wave is interfered with Wireless Communication Service using the same frequency range. In this paper, the Notch Filter and the Spectrum Sensing technology are proposed to reduction of interference between Power Line Communication and Wireless Communication Service. The Spectrum Sensing technology is the core technology of the Cognitive Radio (CR) system. CR is the technology that temporarily allocates the frequency bandwidth by scanning surrounding wireless environments to keep licensed terminals and search the unused frequency bandwidth. The proposed emulator is implemented with Spectrum Sensing and Notch Filter system using Embedded Board.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.1
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• pp.141-150
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• 2010

In this paper, performance of a turbo-coded OFDM system is analyzed and simulated in a power line communication channel. Since the power line communication system typically operates in a hostile environment, turbo code has been employed to enhance reliability of transmitted data. The performance is evaluated in terms of bit error probability. As turbo decoding algorithms, MAP (maximum a posteriori), Max-Log-MAP, and SOVA (soft decision viterbi output) algorithms are chosen and their performances are compared. From simulation results, it is demonstrated that Max-Log-MAP algorithm is promising in terms of performance and complexity. It is shown that performance is improved 3dB by increasing the number of iterations, 2 to 8, and interleaver length of a turbo encoder, 100 to 5000. The results in this paper can be applied to OFDM-based high-speed power line communication systems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.10
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• pp.3756-3760
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• 2010

In this paper we propose network design for power line communication of electric railway using messenger wire. we carried out feasibility study on the power line communication(PLC) using Contact wire and messenger wire which are required at electric railway. First of all, full-duplex data communication was implemented using coupler which is suspended on messenger wire at non-voltage state. We verified data transfer rate was found to be good, and then proposed a design example of PLC network as the main components for PLC. we will study continuously make an effort to verify on the network design of PLC for further study.

• Proceedings of the Korea Contents Association Conference
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• 2010.05a
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• pp.31-33
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• 2010

The image communication system based on power line communication(PLC) that manages the status of workers in deteriorated. work environments such as high temperature and pressures as realtime is designed and implemented in this paper. The major design considerations for system design are such that the adaptation of simple architecture, simplicity of installation and movement, tolerances about high temperature and pressures, transmission of high quality image under various noise environments.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.3
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• pp.497-502
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• 2012

Power line communication(PLC) is a kind of communication technology, was made use of controling a frequency narrow band, but as the PLC technology developing, in the near future get to the commercial step that is broadband PLC upto 30 MHz. This paper deals with the PLC of electric railway using capacitive signal coupler. An AC arrester for catenary is used as a capacitive signal coupler, has the characteristic of capacitor. As a result of field test, a messenger wire used PLC contain much of conducted noise about overall frequency band and also signal attenuation rate increased with increasing frequency between two points. and the communication speed of PLC used messenger wire is 793kbps at a distance of 40m. Experimental results show the possibility of PLC using a messenger wire and an AC arrester for catenary at electric railway.

• 한국정보통신설비학회:학술대회논문집
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• 2009.08a
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• pp.227-230
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• 2009

In this paper, the results of field testing of high-speed power line in-home networking in Korea are reported. When multiple networks share a common channel, they can interfere destructively and reduce system capacity. This is major problem in-home power line communications, especially in MDU deployments. The effects of neighboring network interference in power line communications are reported.