• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전력기술부문
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• pp.376-378
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• 2003

Since the first underground transmission line of Korea was installed between Danginri and Yongsan substations in 1974, the two types of underground transmission power cables, oil-filled and XLPE, have been applied for underground transmission lines. As the manufacturing technologies of XLPE cable have been improved and the simplicity of installation and maintenance has been focused on, the installations of XLPE cables have been largely increased since the mid 1990's. For the first time, in Korea, the 345kV XLPE cable was installed between Youngseo and Youngdeungpo substations in 2003, June. So, this paper introduces the project profile, the design of cable and its accessory, the cable system design, installation and site test.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 추계학술대회 논문집 학회본부 A
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• pp.55-57
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• 2000

This paper presents the measurement of phasor angle of power system using Synchronized Phasor Measurement System(SPMS). SPMS includes the GPS receiver, so it can add the exact time information to the data acquired from the power system by SPMS. Using that data, we can compare the difference of phasor angles of voltages currents acquired at the exactly same time, and monitor the RMS values of voltage and current. In this paper, we present the difference of voltage angles between 345kV Sinjechon S/S and 345kV Asan S/S, where two SPMS were installed separately, and prove their performance by comparing to simulation result of PSS/E.

• 전기학회논문지
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• 제60권10호
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• pp.1811-1816
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• 2011

This paper describes switching surge analysis for reclosing decision in 345kV combined transmission line with GIL. Reclosing operation should be decided based on the detailed technical analysis in combined transmission line because this line includes power cable section which is week on insulation. Insulation of power cable can be breakdown at the week point in case of reclosing moment. Therefore the detailed analysis has to be carried out by considering several conditions such as charging rate, inserting resistance, arrester, length ratio of power cable section, grounding resistance, etc. Analysis is performed by EMTP/ATP.

• 한국안전학회지
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• 제11권3호
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• pp.75-80
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• 1996

This paper presents a study on characteristics and safety for human body in ELF electric and magnetic fields using statistical method. The magnetic fields from a power line can be computed given a knowledge of the currents, voltage and geometry of the line. In this paper, a statistical method for predicting the magnetic fields given the inherent indetermination of the currents is presented. But the electric field is calculated given a knowledge of the voltage and geometry of the line. The effect of unexpected fluctuations in current is modeled by the Monte Carlo simulation. The suggested method is applied to the 345kV and 765kV transmission line system, the result shows that the maximum electric and magnetic field intensity is 6.8627kV/m and 284mG in 345kV system, 2. 5590kV/m and 35mG in 765kV system, respectively.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 A
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• pp.148-150
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• 2002

Recently the demand for electrical power is significantly increased due to the life improvement of customers. Correspond to the result, the transmission capacity is larger, also the fault current is significantly larger. Within the methods of limiting this fault current, the methods of using the fault current limiter is on the rise. If the Superconducting Fault Current Limiter(SFCL) is applied, then the power delivery loss doesn't exist between the plural power systems, also the fault current can be reduce. But for applying the real system, it needs to investigate the effect of SFCL before appling to real power systems. Consequently, the fault of transmission with SFCL was simulated using EMTP. It was investigated to the effect of SFCL at the 345[kV] transmission fault according to compare with the case of appling SFCL and removing SFCL.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1769-1770
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• 2007

To prevent an insulator failure, an automatic cleaning robot was developed for suspension insulator strings. The robot autonomously moves along the insulator string using the clamps installed on its two moving frames, and adopts a dry cleaning method using rotating brushes and a circular motion guide. In addition, a mechanized brush bristles and a voltage-balancing contactor are devised to increase cleaning efficiency and to prevent arc generation under live-line conditions, respectively. Moreover, a manual tool for its installation and removal is presented. We confirmed its effectiveness through experiments.

• Journal of Electrical Engineering and Technology
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• 제8권1호
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• pp.70-79
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• 2013

In this paper, a comparative study on the frequency estimation methods using IRDWT (Improved Recursive Discrete Wavelet Transform), FRDWT(Fast Recursive Discrete Wavelet Transform), and GCDFT(Gain Compensator Discrete Fourier Transform) is presented. The 345[kV] power system modeling data of the Republic of Korea by EMTP-RV is used to evaluate the performance of the proposed two kinds of RDWT(IRDWT and FRDWT) and GCDFT. The simulation results show that the frequency estimation technique based on FRDWT could be the optimal frequency measurement method, and thus can be applied to FDR(Fault Disturbance Recorder) for wide-area blackout protection or frequency measurement apparatus.

• 대한전기학회논문지:전력기술부문A
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• 제52권12호
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• pp.713-721
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• 2003

This paper analyzes the switching overvoltage occurred on 345kV underground power cable system as well as combined transmission system using EMTP. Cable length and closing time, preinsertion resistance have effect on switching overvoltage. Therefore, this paper analyzes the switching overvoltage occurred on conductor and sheath with change of those parameters. Specially, the cross bonding position becomes discontinuity point because of the difference between surge impedance of metal sheath and that of lead cable. Thus, the transmission and the reflection of traveling wave complexly occur at this connection point. According to these influences, voltage between sheath and earth as well as voltage between joint boxes rise. Time to crest point of switching overvoltage is longer than lightning overvoltage. Even though the voltage induced by switching surge is smaller than lightning surge, that voltage may have serious effect on the metal sheath. Therefore, this paper also analyses the reduction effect of switching overvoltage when the preinsertion resistance of circuit breaker is considered.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 C
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• pp.1861-1863
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• 1996

In this paper, measurements and analyses of ELF electric fields in the vicinity of UHV overhead transmission lines and substations have been conducted. Planar-type sensors have been developed with special consideration of picking up lower frequency and spatial components without any distortion. So finally the electric field measuring system has the frequency bandwidth of 7[Hz] to 2.7[MHz] and the response sensitivity of 0.094[mV/V/m]. A brief description of design rules of the measuring system and measurement procedures is introduced. The actual survey near 154 and 345[kV] overhead transmission lines and power subststions was carried out and analyzed. It may be inferred from these results that the electric field intensity exeeds 7[kV/m] only in very few cases particularly at the substations so that the field measurements meet almost limits or guidelines that various authorized international institutes recommend.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2002년도 학술대회 논문집
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• pp.285-290
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• 2002

Power systems are becoming larger and larger for meeting electric power demand. Therefore, the over-currents resulting from contingencies such short circuits are increasing higher. The Maximum short circuit current of modern power system is becoming so large that circuit breaker are not expected th be able to shut down the current in the future. In order to cut over-currents, a system composed of a superconducting fault current limiter(SFCL) and traditional breaker seems to provide a promising solution for future power operation. In present paper, three line-to-ground fault is assumed to happen at the center of 345kV transmission lines in a large capacity electric power system The superconducting fault current limiter was represented using a commutation type, which consists of a non-inductive superconducting coil and current limiting element(resistor or reactor). The introduction merits of the SFCL were investigated quantitatively by RTDS/EMTDC from the viewpoint of current limiting performance, the prevention of the voltage drop at the load bus and comparison characteristics for two type SFCL. Desired design specification and operation parameters of SFCL were also given qualitatively by the performance evaluation of the two type SFCL in the power system.