• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1920-1922
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• 1996

After determining the type and string condition of conductor of 765kV transmission lines, we studied the mechanical strength system of insulator strings to support conductors and insulate conductors from towers. In this paper, for the insulator strings which will be used in 765kV transmission lines, we're going to optimally determine the mechanical strength system and supporting method in the consideration of the reliability, economics and the survey data of T/L routes, and also suggest the calculation method to stipulate for the application limits of suspension and strain insulator strings according to the loadspan and height difference of tower.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1330-1331
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• 1995

This paper deals with the design of conductor stringing of KEPCO 765kV transmission line. The main subject in the design of conductor stringing is the determination on what the stringing tension is. According to the stringing tension, the weight and height of towers and the strength necessary for conductor, hardware, insulator vary, and the construction cost and the reliability of tower are affected largely. Therefore, in order to determine the optimum condition for stringing conductors, We appraised various items : estimation of economic comparision, strength appraisal of conductor, hardware, insulator, etc. After studying these entirely, we present the condition of condutor stringing for KEPCO 765kV transmission line.

• 전기학회논문지
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• 제56권9호
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• pp.1632-1637
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• 2007

This paper analyses current densities induced inside human body of lineman for 765kV transmission line when he wears a protective cloth or not. Applying the boundary element method, we calculate current densities induced in organs inside a worker in case he was located at 15[cm], 30[cm], 50[cm], and 100[cm] far from a prefabricated jumper. As results of study, we find a maximum current density induced in all organs may be higher than $10[mA/m^2]$ if he does not wear protective clothes. We also know high permeability materials can lower current density more than high conductivity materials.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제55권5호
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• pp.231-238
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• 2006

This paper analysed the induced current density inside human body of hot-line worker for 765kV double circuit transmission line according to locations of human body. Human model was composed of several organs and other parts, whose shapes were expressed by spheroids or cylinders. Organs such as the brain, heart, lungs, liver and intestines were taken into account. Applying the 3 dimensional boundary element method, we calculated induced current density in case a worker was located inside and outside a lowest phase of 765 kV transmission line in which a 60% current of maximum load flowed. As results of study, we found a maximum induced current density in all organs was less than $10mA/m^2$ when a wonder was outside. As one in brain and heart was higher than $10mA/m^2$ when a worker was inside, we propose a method for lowering current density.

• 대한전기학회논문지:전력기술부문A
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• 제54권1호
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• pp.25-30
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• 2005

An accurate digital distance relaying algorithm which is immune to mutual coupling effect and reactance effect of the fault resistance and the load current for the line faults in 765kV untransposed transmission lines is proposed. The algorithm can estimate adaptively the impedance to a fault point independent of the fault resistance. To compensate the magnitude and phase of the apparent impedance, this algorithm uses the angle of an impedance deviation vector. The impedance correction algorithm for phase-to-ground fault and phase-to-phase short fault use a voltage equation at fault point to compensate the fault current at fault point. A series of tests using EMTP output data in a 765kV untransposed transmission lines have proved the accuracy and effectiveness of the proposed algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.723-724
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• 2007

Live line work is well known for mending and maintenance of electrical power equipment. Nowadays needs of electric power supply quality require live line work In Korea, live line work is needed since 765kV transmission operation and restructure of electric power industry has changed. In other words, in case of suspension of power supply on the transmission is getting hard to keep up with efficiency of transmission operation, customer's confidence and generation-limited cost. Therefore live line work is very meaningful. As the condition of 765kV Transmission both bare hand and Helicopter live line technique must be used in moderation because of economic, geographical, environmental circumstances around steel tower.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2015년도 제46회 하계학술대회
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• pp.241-242
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• 2015

한국전력계통은 전체 계통부하의 약 40%가 수도권에 집중되어 있다. 반면 발전설비의 경우 설비용량의 약 20%가 수도권에 위치하고 있다. 그러나 이 설비용량의 대부분은 복합 발전소로 구성되어 있다. 향후 동해안 지역의 경우 신한울 원자력 발전소 등 대규모 기저발 전원이 투입될 계획이다. 발전설비의 증가에 따라 전력을 수도권으로 수송하기 위한 송전설비계획도 수립되어 있는 상황으로 위와 같은 계통의 특성이 더욱 심화된다. 2018년의 경우 신한울 원전이 동해안 지역에 신규 투입될 예정이다. 그러나 송전설비계획에 따른 신규 송전선은 이보다 다소 늦은 시기에 투입될 예정이다. 이에 따라 동해안으로부터 수도권으로 전력을 송전하는 765kV 송전선 고장의 파급효과가 매우 심각할 것으로 예상된다. 특히 수도권의 복합이 대부분 정지한 off-peak 부하 상태에서 상정고장이 발생할 경우, 수도권 지역의 전압불안정 문제가 발생할 가능성이 있다. 이 논문에서는 2018년도 계통상황을 기반으로 동해안 765kV 상정고장 상황을 고려하여 수도권 전압안정도를 확보하기 위한 병렬 FACTS설비 투입 개소를 선정하는 방안을 제시한다. 또한 위 방안을 적용한 선정 결과를 제시한다.

• 대한전기학회논문지:전력기술부문A
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• 제48권11호
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• pp.1365-1373
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• 1999

In many countries including Korea, in order to transmit the more electric power, the higher transmission line voltage is inevitable. So, a rapid reclosing scheme is important for EHV/UHV transmission lines to ensure requirements for high reliability of main lines. A critical aspect of reclosing operation is the extinction of the secondary arc since it must extinguish before successful reclosure can occur. Therefore the accurate simulation techniques of arcing faults are of importance. And successful reclosing switching can be accomplished by adopting a proper method such as HSGS and hybrid scheme to reduce the secondary arc extinction time. First of all, this paper discusses a suggested arc model, which have time dependent resistance for primary arc and piecewise linear approximated arc model for secondary arc. And this simulation technique is applied to Korean 765 kV transmission lines. Also hybrid scheme is simulated and evaluated for the purpose of shortening dead time. For adaptive reclosing scheme, variable dead time control algorithm is suggested. Two kinds of algorithm are tested. One is max tracking algorithm and the other is rms tracking algorithm. According to simulation results, rms tracking has less errors than max tracking. Therefore rms tracking is applied to Korean 765 kV transmission lines with hybrid scheme.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1994년도 하계학술대회 논문집 C
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• pp.1509-1511
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• 1994

This paper calculates the induced voltage and current for a human and a car under 765 kV AC double circuit transmission line. A human and a car is simulated as two dimension by the use of charge simulation method and as three dimension by using surface charge method. The phase arrangement of transmission line is varied to calculate the induced voltage and current. In two cases a human and a car is grounded or floated, the induced voltage and current is also compared.

• 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.