• 전기전자학회논문지
• /
• 제18권4호
• /
• pp.442-446
• /
• 2014

본 논문에서는 ACSR 가공송전선로의 전력공급 신뢰도를 증진시키기 위한 비상정격의 적용방안에 대하여 기술하였다. 전력산업의 재편으로 인하여 한국전력은 물론 세계의 대부분 전력회사들은 새로운 투자를 하지 않으면서 경제적인 전략들만 모색하여 왔다. 그러나 전력수요가 급격히 증가하였으나 발전량의 증가는 충분히 따라가지 못했다. 따라서 첨두부하 시나 송전선로의 고장의 경우에 기존 송전선로의 송전용량을 증가시키기 위하여, 단시간 또는 장시간정격과 같은 비상용량을 적용하는 방법을 제안한다. 만약 첨두부하시, 정적송전용량 대신에 장시간 비상용량을 적용하면 10 % 또는 그 이상의 전력증대가 가능하다. 또한 2회선 송전선로 중 1회선 고장이나 과부하 경우에 비상용량이 효과적으로 사용될 수 있음을 확인하였다.

• 조명전기설비학회논문지
• /
• 제21권7호
• /
• pp.20-28
• /
• 2007

본 논문에서는 2회선 가공송전선에 대하여 2회선 중 1회선에 고장이 발생한 경우에 안전하게 운전할 수 있는 단시간정격을 결정하기 위한 해석적 방법을 기술한다. 도체의 온도특성을 나타내는 열평형방정식을 선형화 함으로써 이 선형방정식으로 1회선 선로에 과부하가 발생하는 동안 과전류와 그 온도 특성을 쉽게 표현할 수 있다. 일반적으로 단시간 선로정격은 도체의 수명과 이도를 동시에 고려하여 결정해야 한다는 것은 잘 알려진 사실이다. 그렇지만 대부분의 전력회사는 단시간정격에 대한 각자의 다른 지침을 갖고 있다. 이 논문에서는 제안된 방법을 사용하면 과거 3시기에 건설된 한국전력공사의 가공송전선에 규정된 단시간정격을 재평가할 수 있고, 그 결과 단시간정격을 효율적으로 증대시킬 수 있음을 확인하였다. 또한 이 방법은 2회선 선로 중 1회선에 고장이 발생할 경우에 기존 선로에 어떤 조치도 하지 않아도 단시간 동적송전용량을 결정하는데 직접 이용할 수 있을 것이다.

• 대한전기학회논문지:전력기술부문A
• /
• 제53권8호
• /
• pp.432-437
• /
• 2004

Since the characteristic frequency is decreased in proportion to the fault distance, the characteristic frequency component may be insufficiently eliminated by a low-pass filter on a long transmission line. In order to set a standard for the cut-off frequency of the low-pass filter, this paper proposes a method for obtaining the characteristic frequencies due to line faults. The application results of the proposed method are presented for line to ground (LG) faults and line to line (LL) faults on a 345 kV 200 km overhead transmission line. The EMTP is used to generate fault signals under different fault locations and fault inception angles. By comparison between the characteristic frequencies obtained from the proposed method and the EMTP simulation, it is shown that the proposed method accurately obtains the characteristic frequency.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2009년도 제40회 하계학술대회
• /
• pp.323_324
• /
• 2009

345kV Incheon Thermal Power Plant Transmission Line Collapse Analysis and Countermeasures. The Typhoon Galmaegi which had been formed in July 15, 2008 diminished into a tropical cyclone and cooled the air above the West Sea. The cooled air colliding with the warm inland air caused a strong whirlwind at some places in the west seaside; the whirlwind battered the 345kV Incheon Thermal Power Plant Transmission Line to be collapsed. The resistance against wind pressure, one of the key elements in transmission line engineering, is designed to endure the pressure corresponding to the maximum instantaneous wind speed. Before the above accident happened, no transmission line has ever been collapsed by a whirlwind. So this paper is aimed to analyze causes that collapsed 345kV Incheon Thermal Power Plant transmission line and to introduce countermeasures.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2008년도 제39회 하계학술대회
• /
• pp.335-336
• /
• 2008

Overhead transmission lines are mainly crossing mountainous area. They are easily affected in weathers like typhoon, strong wind, lightning, heavy rain, or heavy snow. Sometimes these weathers cause transmission line faults. A lightning flashover is most often fault. Nowadays lightning density in KOREA is growing high and lightning flashovers occur more often. A lightning flashover on transmission line is mostly cleared by momentary operation of a circuit breaker, so power failure happens rarely. However, when both circuits trip simultaneously due to the lightning flashovers on double circuit transmission line, short time power failure and voltage drop happen. KEPCO has used transmission line arresters to avoid double circuit simultaneous trip out since 2003. And transmission line arresters cannot be installed with KEPCO's present metal fittings, so various fittings have been used for each transmission line arrester manufacturer. This paper introduces development and standardization of arc-horn and metal fittings for transmission line arrester which can be used for both existing lines and new lines in KEPCO.

• 대한전기학회논문지:전력기술부문A
• /
• 제52권10호
• /
• pp.593-601
• /
• 2003

Distance realy is tripped by the line impedance calculated at the relay point. Accordingly the accurate operation depends on the precise calculation of line impedance. Impedance can be accurately calculated in case of overhead line. However, in case of power cables or combined transmission lines, impedance can not be accurately calculated because cable systems have the sheath, grounding resistance, and sheath voltage limiters(SVLs). There are also several grounding systems in cable systems. Therefore, if there is a fault in cable systems, these terms will severely be caused much error to calculation of impedance. Accordingly the proper compensation should be developed for the correct operation of the distance relay. This paper presents the distance calculating algorithm in combined transmission line with power cable using wavelet transform. In order to achieve such purpose, judgement method to discriminate the fault section in both sections was proposed using D1 coefficient summation in db4. And also, error compensation value was proposed for correct calculation of impedance in power cables section.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.519-521
• /
• 2003

This paper presents a frequency analysis of subspan oscillation on overhead transmission line. The Oscillation frequency is a natural characteristic of a subspan and can be calculated. But it is not same to calculated frequency, because it has been composed several frequencies of adjacent subspan. We were analyzed to the frequency of subspan oscillation by FFT methods. This result will use to establish of the subspan location rules.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2003년도 하계학술대회 논문집 A
• /
• pp.522-524
• /
• 2003

This paper presents a stability estimation method for subspan oscillation on overhead transmission line. It has been used method by conductor's fatigue limit or subspan oscillation amplitude. But it is not proper to estimation of subspan oscillation. We suggest to instability index for estimation method of subspan oscillation. And we tried to 4 bundled conductor system. This result will use to establish of the subspan location rules.

• Wind and Structures
• /
• 제3권4호
• /
• pp.243-253
• /
• 2000

To develop galloping suppression devices, it is important to understand the effects of wind turbulence on galloping and to establish an evaluation method which takes 'large conductor deformations' into account. This paper introduces some findings on galloping in gusty wind obtained by numerical simulation using a model based on the Mogami Test Line of the Tokyo Electric Power Co. The equations of motion of the conductor are based on the Lagrangian formulations by Simpson, and they are made discrete in accordance with a finite element method.

• 대한전기학회논문지:전기물성ㆍ응용부문C
• /
• 제55권5호
• /
• pp.245-249
• /
• 2006

Corona characteristics of conductors are dependent on the electric field conditions in the immediate vicinity of the conductors. In case of DC transmission line, particularly, the space charge plays an important role in the electric field distribution. Therefore, DC corona cage simulation is necessary for long-term test in the same conditions. This paper presents the results of designing and constructing hardwares such as DC power supply, measurement system and DAS to carry out the simulation. The corona cage longitudinally is divided into five equal length sections and three inner sections of those are isolated from the ground of outer cage. The measurement items are radio noise, corona current, television noise, audible noise and meteorological conditions. In the next step, various simulations about the type and configuration of two or three candidate conductors will be conducted. And then finally an environmentally-friendly conductor for HVDC overhead transmission line will be decided.