• KIEE International Transactions on Power Engineering
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• v.5A no.1
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• pp.31-39
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• 2005

This paper illustrates a tie line constrained equivalent assisting generator (TEAG) model considering forced outage rates of transmission systems for reliability evaluation of interconnected power systems. Interconnections between power systems can provide improved levels of reliability. It is expected that the TEAG model developed in this paper will prove useful in the solution to problems related to the effect of transmission system uncertainties in the reliability evaluation of interconnected power systems. It is important that interconnection between power systems can provide the improved levels of reliability. Therefore, It is expected that the TEAG model developed in this study will provide some solution among many problems for interconnected power systems as an optimal tie line capacity and a connected point between assisting systems and assisted system. The characteristics and validity of this developed TEAG considering transmission systems are introduced by case study of three IEEE MRTS interconnected.

• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.1301-1304
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• 2005

In this paper, we used class D amplification circuit proposed to improve the decline of error rate caused by rapidly variable impedance in the Power Line Communication. We manufactured voltage drive circuit and current drive circuit that are driven circuit of power line modem on the present. And with the same power line modem, we made a comparison experiment applying the driver circuit that used class D amplifier proposed in this paper. As a result of Experiment, We showed that it has more superior than other existing drive circuits at the impedance change in the power line communication.

• Journal of Power Electronics
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• v.15 no.5
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• pp.1168-1177
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• 2015

This paper presents a scheme to improve the line current distortion of power factor corrector (PFC) topology at the zero crossing point using a predictive control algorithm in both the continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The line current in single-phase PFC topology is distorted at the zero crossing point of the input AC voltage because of the characteristic of the general proportional integral (PI) current controller. This distortion degrades the line current quality, such as the total harmonic distortion (THD) and the power factor (PF). Given the optimal duty cycle calculated by estimating the next state current in both the CCM and DCM, the proposed predictive control algorithm has a fast dynamic response and accuracy unlike the conventional PI current control method. These advantages of the proposed algorithm lower the line current distortion of PFC topology. The proposed method is verified through PSIM simulations and experimental results with 1.5 kW bridgeless PFC (BLPFC) topology.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.41 no.11
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• pp.25-32
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• 2004

In this paper, we first analysed the ability of DSSS resistance against noises, which are main interferences to the four types in power line communications. Based on the characteristic of these noises, we made a noise source of power line which is similar with the result measured, in practice. We simulated and analysed the BER performance of BPSK with DSSS over this noise model and one without the DSSS, for comparison. Result showed that the BPSK with DSSS system has improved by 8 dB, as compared to those without the DSSS, as against power line noises.

• Journal of the Korean Society of Safety
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• v.33 no.5
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• pp.164-169
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• 2018

A detailed fatigue evaluation procedure was developed to mitigate the excessive conservativeness of the conventional environmental fatigue evaluation method for the pressurizer spray line elbow of domestic new nuclear power plants. The pressurizer spray line is made of austenitic stainless steel, which is relatively sensitive to the environmentally assisted fatigue, and has a low degree of design margin in terms of environmentally assisted fatigue due to the thermal stratification phenomenon on the pipe cross section as a whole or locally. In this study, to meet the environmental fatigue design requirements of the pressurizer spray line elbow, the new environmental fatigue evaluation has been performed, which used the ASME Code NB-3200-based detailed fatigue analysis and the environmental fatigue correction factor instead of the existing NB-3600 evaluation method. As a result, the design requirements for environmentally assisted fatigue were met in all parts of the pressurizer spray line elbow including the fatigue weakened zones by thermal stratification.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.1
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• pp.217-223
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• 2012

Time synchronization problems is very important in everyday life and a variety of industries, In this paper, we developed PLB(Power Line Broadcasting) system which broadcast time information to each device through power line modems. In our system, the smartphone synchronized to GPS time is used as a time source and we propose, develop and evaluate a relay system to solve the difficulties of long-distance transmission of power line modem technology.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2263-2268
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• 2008

We investigated the malfunction and destruction characteristics of microcontroller devices under high power electromagnetic(HPEM) wave by magnetron. HPEM was rated at a microwave output of 0 to 1,000 W, at a frequency of 2,450${\pm}$50 MHz and was radiated from the open-ended standard rectangular waveguide(WR-340) to free space. The influence of different reset-, clock-, data-, and power supply-line lengths has been tested. The variation of the line length was done with flat cables. The susceptibility of the tested microcontroller devices was in general much influenced by clock-, reset-, and power supply-line length, little influenced by data-line length. Further the line length was increased, the malfunction threshold was decreased as expected, because more energy couples to the devices. The surfaces of the destroyed microcontroller devices were removed and the chip conditions were investigated with microscope. The microscopic analysis of the damaged devices showed component and bondwire destructions such as breakthroughs and melting due to thermal effects. The obtained results are expected to provide fundamental data for interpreting the combined mechanism of microcontroller devices in an intentional microwave environment.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.54 no.6
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• pp.409-416
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• 2005

For broadband high-data-rate power line communication with the allocated frequency bandwidth from 2 to 30 MHz on medium voltage (MV) distribution power lines, a signal coupling unit is developed. The coupling unit is composed of a coupling capacitor for coupling communication signal, a drain coil, and an impedance matching part. The coupling capacitor made of ceramic capacitor is designed for transmission property of better than 1 dB in the frequency range. The drain coil is used for preventing low frequency high voltage from junction of medium voltage power line in case that a coupling capacitor is not working properly any more. Also, using ferrite core, a novel broadband impedance matching transformer is developed. A complete coupling unit with a coupling capacitor, a drain coil, and a matching transformer is housed by polymer for good isolation and distinguishing from high voltage electric facilities. Each is fabricated and its frequency behavior is tested. Finally, complete signal couplers are equipped in a MV PLC test bed and their performance are measured. The measurement shows that the coupling capacitor works excellently.

• The Journal of the Korea institute of electronic communication sciences
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• v.14 no.1
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• pp.127-136
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• 2019

The public address system should be easily operated and managed by the users, and guaranteed to serve stable working in an emergency and a crisis. In this paper, In this paper, to provide power line communication based public address system users with convenience and efficiency, we implement a firmware to control communication between a PLC(: Power Line Communication) controller of the public address system and UI(: User Interface) and between a PLC controller of the public address system and PLC speakers, and develop a UI software.

• Proceedings of the KIEE Conference
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• 1999.07d
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• pp.1569-1571
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• 1999

In this work, we have performed the application experiment for real distribution line to diagnose the underground power cables using DC voltage decay measurement system. We have also performed the Isothermal Relaxation Current test for the same distribution line using KDA-l. We could confirmed possibility of grading the insulation aging state of underground power cables. Therefore, we conclude that it is possible to apply DC voltage decay method to the real distribution line.