• Journal of Mechanical Science and Technology
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• 제16권12호
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• pp.1633-1642
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• 2002

Uninterrupted power supply has become indispensable during the maintenance task of active electric power lines as a result of today's highly information-oriented society and increasing demand of electric utilities. The maintenance task has the risk of electric shock and the danger of falling from high place. Therefore it is necessary to realize an autonomous robot system using electro-hydraulic manipulator because hydraulic manipulators have the advantage of electric insulation. Meanwhile it is relatively difficult to realize autonomous assembly tasks particularly in the case of manipulating flexible objects such as electric lines. In this report, a discrete event control system is introduced for automatic assembly task of electric lines into sleeves as one of the typical task of active electric power lines. In the implementation of a discrete event control system, LVQNN (linear vector quantization neural network) is applied to the insertion task of electric lines to sleeves. In order to apply these proposed control system to the unknown environment, virtual learning data for LVQNN is generated by fuzzy inference. By the experimental results of two types of electric lines and sleeves, these proposed discrete event control and neural network learning algorithm are confirmed very effective to the insertion tasks of electric lines to sleeves as a typical task of active electric power maintenance tasks.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1908-1910
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• 1997

The electric and magnetic fields (EMFs) near 345/154 kV overhead transmission lines were measured. The average values of maximum electric field and magnetic field for 44 transmission lines were 1.11 kV/m and 24.5 mG, respectively. These values were lower than any standards of advanced countries. The EMFs of distribution lines and substation, and electric appliances were also measured and compared with those of transmission lines.

• KEPCO Journal on Electric Power and Energy
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• 제6권3호
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• pp.271-278
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• 2020

KEPCO Research Institute developed a GIS-based autopilot drone inspection system for electric power facilities and since its pilot application in 2017, it has been successfully used to detect defects in power transmission lines. This paper presents how to operate this system in the field of power line inspection. Power transmission lines are located in a wide variety of environments such as plains, mountains, river crossings, sea crossings, and industrial areas. Among these, some transmission lines are difficult for human workers to access because of their geographies and some should be checked more often due to their severe contamination. Considering these field conditions, we classified drone operation in two categories to increase its effectiveness and efficiency - patrol surveillance and detailed inspection tasks. This paper describes the detailed procedures of the two tasks above and their field application experiences. In addition, this paper newly proposes how to construct public drone roads by using the information of KEPCO's power transmission lines.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.337-338
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• 2008

KEPCO has built, for the first time in the world, 765㎸ double circuit transmission lines which use vertically arranged phase conductor, while 765㎸ transmission lines in other countries are single circuit lines and use horizontally arranged phase conductor. System operating voltage, switching overvoltage, and lightning overvoltage were considered in determining the air gap. Recently, however, lightning outage rate of some 765㎸ transmission lines in KOREA shows that it is more than what is expected. Lightning fault of 765㎸ transmission lines is mostly single phase grounding fault which can be reclosed. But it still needs to be carefully managed, for the bulk system like 765㎸ transmission lines have huge effects on whole power system. This paper introduces analysis and countermeasure of KEPCO's 765㎸ transmission line lightning outage.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1996년도 추계학술대회
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• pp.353-356
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• 1996

Early this year the construction of new high voltage power lines have been forced to stop due to the demonstration of residents in Kwa-chun. According to mutual agreement between the residents and Korea Electric Power Corporation, electromagnetic field(EMF) from present power lines was measured and EMF after completion of new power lines was estimated. The results show that EMF near power lines Is relatively low, and EMFnear electric substation is quite high due to the short distance between the power lines and ground. For 4 conduction 345kV line, magnetic field decreases to 3mG at the distance of 50m from the power line.

• 한국전기전자재료학회논문지
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• 제30권10호
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• pp.672-676
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• 2017

Electrical energy is playing an increasingly vital role as the primary energy source in everyday life. With the increase in electric power consumption, power facilities are under an increasing stress and must operate at a high capacity. Consequently, the demand for electric power cables in power transmission and distribution lines is rapidly increasing. Underground distribution lines have been steadily replacing the aboveground lines owing to the increase in electric power demand and the need to increase the supply voltage. In addition to line damage, worker safety is of primary concern in this type of underground infrastructure. In this study, to improve the safety of workers dealing with underground transmission lines, we analyzed the electromagnetic field generated around the distribution line and determined the basic criteria for developing a device that can detect a live underground line.

• KEPCO Journal on Electric Power and Energy
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• 제8권2호
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• pp.49-53
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• 2022

The distribution live-line work method is an operation method of working in a state in which electricity flows through overhead distribution lines to minimize inconvenience to electric customers due to power failure. In June 2016, to strengthen the safety of electrical workers, Korea Electric Power Corporation announced that it would in principle abolish the rubber glove method, in which workers wore protective equipment such as rubber gloves and performed their maintenance work. In addition, KEPCO announced that it would develop a short-range live working method using smart sticks and an advanced live-line maintenance robot system where workers work without touching wires directly. This paper is a preliminary study for the development of the live-line maintenance robot system, and deals with the results of analyzing the technical feasibility of whether the live works performed by workers can be replaced by robots or not.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 하계학술대회 논문집 C
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• pp.1103-1105
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• 1998

It is becoming more and more difficult to construct new transmission lines because of many social problems. According to the load increase, Some of existing transmission lines will be heavy loaded over the limit. To solve this situation, one of method is peformed by replacing existing ACSR transmission lines with STACIR for increasing power transmission capacity in the 345kv transmission system. This paper presents several techniques for design and construction of transmission line replacement based on the actual experience in the 345kv Shinseongnam-Shinsiheung and Shinseongnam-Shinyeongseo transmission lines.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 E
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• pp.2368-2370
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• 1999

A nationwide survey for electric and magnetic fields(EMFs) near overhead transmission lines has been conducted. The median values of the electric and magnetic fields of 208 transmission lines were 0.50 kV/m and 12.6 mG, respectively. The maximum values were 3.16 kV/m and 125 mG. The measured EMFs were compared with the calculated ones. The causes of the discrepancy between measured and calculated EMFs are also discussed.

• Progress in Superconductivity
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• 제5권2호
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• pp.118-123
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• 2004

We investigated quench distribution in AU/YBCO thin film meander lines with a heater. Quench distribution during faults is important for superconducting fault current limter applications, because uniform quench allows application of higher voltages across the meander lines. AU/YBCO thin films grown on sapphire substrates were patterned into meander lines by photolithography. Gold films grown on the rear sides of the substrates were also patterned into meander lines, and used as heaters. Meander lines on the front and the rear sides were connected in parallel. The meander lines were subjected to simulated AC fault currents for quench measurements during faults. They were immersed in liquid nitrogen during the experiment for effective cooling. Resistance of the AU/YBCO meander lines initially increased more rapidly with the rear heater than without, and consequently the fault current was limited more. The resistance subsequently became similar, The resistance distribution was more uniform with the heater, especially during the initial quench. Quench was completed more uniformly and significantly earlier. This resulted in uniform distribution of dissipated power. These results could be explained with the concept of quench propagation, which was accelerated by heat transfer across the substrate from the rear heater.