• The Transactions of the Korean Institute of Electrical Engineers C
• /
• v.48 no.7
• /
• pp.542-549
• /
• 1999

Corona discharges form at the surface of a transmission line conductor when the electric-field intensity on the conductor surface exceeds the breakdown strength of air. In order to decrease the electric-field intensity on the conductor surface, a new 6 conductor bundle has been studied. This bundle, hybrid conductor bundle, consists of using a larger subconductor at the bottom two conductor positions in the 6-conductor bundles of each phase of the line. The electric field on these two larger subconductors is reduced which in turn reduces the corona noise. It is shown that this is a better solution for decreasing the electric-field intensity than ether the conventional bundle or the asymmetric bundle proposed by EPRI.

• Journal of KSNVE
• /
• v.7 no.5
• /
• pp.729-736
• /
• 1997

The subspan oscillation is the most important in bundled transmission lines, which can cause conductor damage and transmission line hardware failures. So it is necessary to analyze the subspan oscillation in details for transmission lines. This paper suggests the basic concept and theoretical analysis method of subspan oscillation for 6 bundle conductor transmission line, which considers wind speed, subspan length and conductor tension. Especially this paper uses a spacer damper model with clamp-arm flexibility and damping characteristics. Theoretical analysis results are proposed.

• Transactions of the Korean Society for Noise and Vibration Engineering
• /
• v.13 no.9
• /
• pp.671-678
• /
• 2003

Spacer dampers maintain the constant gaps between each conductor in a bundle conductor-transmission line, and are installed at proper intervals to keep a line from all sorts of damages derived from the vibration energy caused by mechanical or electrical external factors. It is most important to embody a technology which considers difficulties of maintenance and repair, and has optimum elements in order to prevent accidents such as destruction by fire or the snapping of a wire by the effect of vibration phenomenon coming from transmission line. In the present thesis, therefore, the analysis of vibratory characteristics of spacer damper is set up by analytical methods such as the analysis of conductor motion's governing equation, the equation of spacer damper's motion, spacer damper-fastened wire's motion in a span, and the numerical analysis of finite difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter we will be able to analyze all kinds of vibration phenomena coming from a boltless spacer damper with 6 bundle conductor for 765 k V transmission line based on new analytical methods.

• Journal of Electrical Engineering and Technology
• /
• v.9 no.6
• /
• pp.2089-2097
• /
• 2014

Negative corona onset characteristics of the stranded conductors based on the ultra-high voltage (UHV) corona cage were studied in the paper. Based on the corona self-sustaining criterion in extreme uneven electric fields and the secondary emission process of the photoelectrons, the corona onset calculation model in the UHV corona cage is established and the corona current tests of the single LGJ900-75, 6 bundle LGJ900-75, 8 bundle LGJ400-35 conductors in dry and rain conditions were done in the UHV corona cage, and the rain rates are 2.4 mm/h, 20 mm/h and 30 mm/h. Corona onset electric field strength is gained by E-I tangent method, and the onset electric field strength in dry condition proves that the calculation model can be used to calculate the corona onset characteristics of the bundle conductors in the UHV corona cage. A further analysis proves that: the negative corona onset voltage of the conductor increases with the bundle number and the diameter of the sub conductor, but decreases with the bundle space in the corona cage. The onset electric field strength is influenced little by bundle space and bundle number, but decreases with the increase of the diameter of the sub-conductor. The surface irregularity coefficient decreases with the rain rate.

• Journal of KSNVE
• /
• v.6 no.1
• /
• pp.89-95
• /
• 1996

If the transmission line voltage is greater than 500kV, audible noise (AN) and hum noise (HN) due to corona discharges on the conductor would be an important design factor for the conductor selection of transmission line. Also there is an aeolian noise: wind noise(WN) from the tower and the conductor due to wind. This paper presents the results of a statistical analysis of audible noise, hum noise, aeolian noise of 6-480mm$^{2}$ conductor bundle in KEPRI 765kV Test Transmission Line which was constructed to develop 765kV double circuit AC transmission line for the first time in the world. The result of the analysis shows that 6-480mm$^{2}$ conductor bundle and tower satisfy configuration the audible noise design criterion of 50dB(A).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.17 no.3
• /
• pp.110-118
• /
• 2003

Spacer dampers maintain the constant gaps between each conductor in a bundle conductor-transmission line, and are installed at proper intervals to keep a line from all sorts of damages derived from the vibration energy caused by mechanical or electrical external factors. It is most important to embody a technology which considers difficulties of maintenance and repair, and has optimum elements in order to prevent accidents such as destruction by fire or the snapping of a wire by the effect of vibration phenomenon coming from transmission lint In the resent thesis, therefore, the analysis of vibratory characteristics of spacer damper is set up by analytical methods such as the analysis of conductor motion's governing equation, the equation of spacer damper's motion, spacer damper-fastened wire's motion in a span and the numerical analysis of finite difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter difference method. Furthermore, the installation distance between spacer dampers was scrutinized by simulations of various vibration phenomena which change at any time as actual conditions do, and hereafter we will be able to analyze all kinds of vibration phenomena coming from a boltless spacer damper with 6 bundle conductor for 765kV transmission line based on new analytical methods.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.4
• /
• pp.612-615
• /
• 1996

Audible noise from corona discharge had been identified as one of the most important factors in the design of conductor configurations for high-voltage transmission lines. 500kV and above. Therefore this paper describes audible noise characteristics of 6 X 480mm conductor bundle in KEPRI 765kV Test Line and Corona Cage. Prediction formula for audible(corona) noise on a 765kV transmission Line was developed using this results.

• Proceedings of the KIEE Conference
• /
• 2000.07a
• /
• pp.131-133
• /
• 2000

Single phase simulations were carried out in order to determine a solutive conductor to the aeolian noise which will be locally applied to 765 kV transmission lines Basic solutive conductors have already been proposed including conductors equipped with spiral rod. low noise conductor of a special shape and others. A low aeolian noise conductor, however, should have excellent corona characteristics in addition to aeolian noise reduction function. In this paper, we compared the performances of the audible noises and radio interferences of 6 candidate conductor bundles by using corona cage. We also developed two programs to need for evaluating environmental effects of each conductor bundle. Those are a program to calculate the conductor surface gradient of various special bundles and a conversion program of single phase data to the model of transmission line. The future determination on the final low aeolian noise conductor will be made through a long-term test to verify environmental impacts at the full-scale Kochang 765 kV test line.

• Proceedings of the KIEE Conference
• /
• 1989.11a
• /
• pp.197-200
• /
• 1989

The corona interference of extra high voltage (EHV) transmission lines has to be considered as an important design factor for establishing an electrical environmental countermeasure at a basic line design stage. This paper describes the conductor selection procedure through both corona performance test result in corona cage and its evaluation by the design criterion. It is known that three conductor configurations including $6{\times}810mm^2$ (spacing: 40 cm) are the suitable conductor bundle for the environmental preservation around both 2-circuits and 1-circuit T/L.

• The Transactions of the Korean Institute of Electrical Engineers
• /
• v.45 no.3
• /
• pp.451-455
• /
• 1996

This paper specified the measurement results conducted by the Korea Electric Power Research Institute (KEPRI) 765kV double circuit transmission test line that measured the audible noise, hum noise, radio interference, electric field and aeolian measurement. This test line consists of 6-480mm$^{2}$ conductors per phase. The analysis of the test results shows that this 6-Rail conductor bundle satisfies the audible noise criterion under the stable rainy weather condition and the radio interference level under the fair weather. And the other items are also agreed with the design level criterion. (author). 9 refs., 7 figs., 2 tabs.