• KEPCO Journal on Electric Power and Energy
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• v.5 no.2
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• pp.75-81
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• 2019

In this study 24 power transmission towers were selected by considering various variables such as power transmission capacity, height and structural type to evaluate their seismic performance using the standard design response spectrum recently announced by the government. In addition, the stresses and sectional forces generated by the current design wind loads and revised seismic ones were compared to review the effects on the design of power transmission towers when the government-required seismic standards were raised. The results of seismic performance evaluation for the target power transmission towers showed that they had seismic capacity of 0.31~0.91g, and that they met the level of the earthquake-resistant special grade, which is the 2,400-year earthquake return periods and secured seismic safety. Further, the sectional forces caused by earthquakes in the towers were 33~82.5% of the ones due to wind loads, and it was also confirmed that the design wind loads were more dominant than design earthquake ones under the elevated seismic standards.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.8
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• pp.645-650
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• 2010

The continuous increase demand for electric power leads to the additional construction of transmission facilities, but it is not easy to acquire right-of-way for transmission facilities. Therefor, there is a need for compact tower that can be built on a narrow right-of-way the compact tower with polymer insulation arm is a solution. It can be upgrading conventional 154 kV transmission line voltages to 345 kV levels. However transmission voltage is increasing, environment interference (corona noise, radio interference, etc.) will occur gradually. This environment interference is depending on the electrical clearances of tower and configuration of conductors. Therefore the analysis of the factors of environmental interference is necessary in order to upgrading transmission voltage. This paper presents the design factor of a compact tower to meet the environmental interference standard.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.2
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• pp.78-85
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• 2012

Low-Voltage power lines should equip surge protection devices which protect electronic equipments and human lives against lightning and abnormal voltages. Data transmission capacity of the power line is determined by frequency characteristics of the surge protective devices. To analyze the effects of surge protective devices on the data transmission performance, various combinations of installation methods are tested which include ZnO varistor elements that is compatible with class I, class II and class III. The result claims that ZnO varistor for class III is found to be one of the main factors that deteriorates the transmission performance. To overcome this problem a serial connection methed between Gap type SPD and ZnO varistor is proposed. With the proposed scheme, laboratory experimental results show that the data transmission performance can be improved up to 91.9[%] with proper SPD combination.

• 제어로봇시스템학회:학술대회논문집
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• 2002.10a
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• pp.79.6-79
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• 2002

We propose here sequential 2 methods for obtain information of current or potential data for power transmission line. One is a digital data transmission unit, this is, an output of a current sensor of power transmission line is digitalized by use of an easy asynchronous protocol. The unit has high speed transform rate, easy making header caused of consisting of only logic circuit. The other is, the output of the unit is transformed via LAN interface and displayed on a personal computer. We have confirmed remote measuring using the method for 100A and 240 A of the current information of power transmission line. Therefore we will be able to see a current waveform by use of internet at a cheep c...

• Proceedings of the KIEE Conference
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• 2003.07a
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• pp.199-201
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• 2003

Because of Korean power system characteristics and increasing power demand, the need of 765kV transmission line is growing gradually. Now a days, KEPCO's 765kV transmission line has been tested and stands for commercial operation. During the first stage, 765kV transmission line will be operated with two voltage grades of 765kV and 345kV, which results the unbalance of power system. So unbalanced current such as zero sequence current flows in the transmission line. In this paper, we describes the simulation study of 765/345kV parallel transmission line by using EMTDC program.

• Journal of information and communication convergence engineering
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• v.9 no.6
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• pp.676-682
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• 2011

Sybil attack can disrupt proper operations of wireless sensor network by forging its sensor node to multiple identities. To protect the sensor network from such an attack, a number of countermeasure methods based on RSSI (Received Signal Strength Indicator) and LQI (Link Quality Indicator) have been proposed. However, previous works on the Sybil attack detection do not consider the fact that Sybil nodes can change their RSSI and LQI strength for their malicious purposes. In this paper, we present a Sybil attack detection method based on a transmission power range. Our proposed method initially measures range of RSSI and LQI from sensor nodes, and then set the minimum, maximum and average RSSI and LQI strength value. After initialization, monitoring nodes request that each sensor node transmits data with different transmission power strengths. If the value measured by monitoring node is out of the range in transmission power strengths, the node is considered as a malicious node.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.18 no.9
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• pp.913-919
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• 2008

Dynamic characteristics of a wrist power transmission of an industrial robot are studied. The wrist power transmission has complex structure characteristics, because it is composed with several shafts and gear system. We used an analytical method to investigate the dynamic characteristics. An analytical model is a rigid model which is composed with masses and springs. Both bearing and gear contact model represent equivalent stiffness springs which are determined by the experiment. In order to investigate the dynamic tendency of the robot wrist power transmission, we simulate the analytical model. There is a dynamic analysis tool which is called the RecurDyn. To verify the analytic results, we experiment a signal analysis which is an overall noise level of the robot. By the parametric study of the element of the robot, we study an improvement method of dynamic characteristics.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.04a
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• pp.150-155
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• 2008

Dynamic characteristics of a wrist power transmission examine closely with mass property, to present a model which is able to induce the vibration is ultimately the purpose. A robot wrist power transmission for analysis model gets the mass property through the approach to be the experimental. A bearing equivalent stiffness which supports the axis and a gear contact equivalent stiffness are determined by the simplicity analysis model compared the result of the experiment. We calculate the vibration tendency of the robot wrist power transmission by an analysis tool which is called the RecurDyn. We compared it with a signal analysis experiment's which a robot operation happens which is based on the ambient noise.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2004.05a
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• pp.243-246
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• 2004

The dynamic characteristic of a wrist power transmission examine closely with mass property, to present the model which induce the vibration is ultimately the purpose. A robot wrist power transmission for analysis model got the mass property through the approach to be the experimental. A bearing equivalent stiffness which supports the axis and a gear contact equivalent stiffness are determined by the simplicity analysis model compared the result of the experiment. We calculate the vibration tendency of the robot wrist power transmission by an analysis tool which is called the RecurDyn. We compared it with a signal analysis experiment's which a robot operation happens which is based on the ambient noise.

• Journal of electromagnetic engineering and science
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• v.15 no.2
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• pp.104-110
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• 2015

As civil infrastructures continue to deteriorate, the demand for structural health monitoring (SHM) has increased. Despite its outstanding capability for damage identification, many conventional SHM techniques are restricted to huge structures because of their wired system for data and power transmission. Although wireless data transmission using radio-frequency techniques has emerged vis-$\grave{a}$-vis wireless sensors in SHM, the power supply issue is still unsolved. Normal batteries cannot support civil infrastructure for no longer than a few decades. In this study, we develop a magnetic resonance-based wireless power transmission system, and its performance is validated in three different mediums: air, unreinforced concrete, and reinforced concrete. The effect of concrete and steel rebars is analyzed.