• The Journal of Korean Institute of Communications and Information Sciences
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• v.4 no.1
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• pp.32-37
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• 1979

The corona noise level at the place 10m and the frequency 1MHz from the new 345KV transmission line is 72dB in the maximum rain-fall and 63dB due to the wet conductors. The synthesized corona noise level of all 3 phases dominantly depends on the phase which has maximum corona level among them. The measured characteristic of the variation with distance from the line coincided well with the theoretically calculated value in this paper. The corona noise level was the highest level in rainy weather or snow-fall. It takes a few hours, for the corona noise to be stable after a rain-fall or snow-fall. The measured value of the corona noise level corresponds quite well with the formula for the corona noise level revision. It was necessary to quantize S/N ratio into radio reception quality for the radio interference due to the transmission line. Some regulations for radio reception quality were defined through long term experiments and ratings by ITU, IEEE comittee, NHK in Japan and others. Fixing our own regulation about radio reception quality should be required.

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

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.11
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• pp.520-526
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• 2006

Corona interferences, such as radio noise, audible noise and television noise, need to be taken into account in the design of HVDC transmission line conductor configuration. Therefore the line designer requires data from which to estimate the corona performance of any set of conductors. To get a sufficiently complete set of design data, it is necessary to examine the corona test of a large number of conductor geometries. This paper presents the results of corona cage test among three types of candidate conductors. It is quite clear from test results that the conductor geometries play an important role in establishing the magnitude of corona noise. Corona noise data from corona cage test are expressed as a statistical distribution of results obtained over long periods of time and various weather conditions. Therefore we can determine an environmentally-friendly conductor bundle for HVDC overhead transmission line. Based on this finding results, various simulations about HVDC line configurations, such as pole space and pole height, will be conducted. And then finally an optimal configuration for HVDC transmission line will be decided.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.50 no.12
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• pp.556-560
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• 2001

To solve aeolian noise, we have tried several special conductor bundles equipped with spiral rod and one kind of low aeolian noise conductor with a special shape. Charge simulation method was applied to analyze electric field distributions of them in transmission line and corona cage for investigating the corona characteristics. This paper describes the electric field distributions and the performances of audible noise and radio interference from the special bundles in 765 kV transmission line by using corona characteristics obtained from corona cage simulation.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.15 no.1
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• pp.44-50
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• 2001

The largest problem in applying the elecbical partial discharge measurement method the transformer that has been operated until now is the removal of external corona noise In this thesis, a methcd was studied. to rneasme only fue partial discharge sIgnal due to the defoct in transfonrer except the external corona noise. To find out the types of partial discharge and corona noise within a transfomr, a partial discharge was made in use of a needle-plane electrodes within a model transfonner and, at the same time, an external corona noise was generated in use of a rod-sphere electrcdes in the air around the transformer. Both of a partial clischarge signal caused from an intemat defect within a transformer and an external noise were found at the rogowski coil which was located at transformer earth wire. When the external corona noise, which was separately measured in use of an antenna sensor out of transfonner, was removed from the signal measured on rogowski coil, the signal caused by partial discharge within a transformer would effectively be acquired.quired.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.55 no.5
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• pp.245-249
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• 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.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.399-402
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• 2001

In this paper, 3-dimensional charge simulation method was applied to analyze electric field distributions of special conductor bundles equipped with spiral rods for reducing aeolian noise in a corona cage. Comparing electric field distributions of special conductor bundles in 765kV transmission tine with ones in corona case, we decide experimental voltages of special conductor bundles in corona cage.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.5
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• pp.508-515
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• 1990

This paper describes the corona characteristics of conductor bundle for EHV transmission line. To reduce the corona noise, the asymmetric conductor bundle to minimize the electric field of the conductor surface is proposed. The charge simulation method is used to formulate the electric field of conductor surface and the optimal arrangement of subconductor to minimize it is selected to apply the nonlinear successive quadratic programming. Through the analytical comparison and the corona cage test, it is proved that the asymmetric conductor bundle proposed in this paper can reduce the average maximum electric field of the phase conductors and the corona noise more than the conventional symmetric conductor bundle and asymmetric conductor bundle by GE.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.14 no.12
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• pp.1032-1040
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• 2001

In order to apply the partial discharge measuring technique utilizing electrical pulse to the transformer at sites, this paper describes the measuring technique obtaining only the signals due to internal partial discharge in the transformer, but the noises due to external corona which has been a major problem so far. At first, partial discharge and corona noise were simultaneously generated in the model transformer by using needle-plane electrodes and rod-sphere electrodes out of it in a high voltage laboratory, respectively. It was verified that only the partial discharge signals in the transformer could be measured by removing the noise signals from the superposed signals of partial discharges and noises on the grounding wire of the model transformer. By application to a 345kV transformer in service, it was also confirmed that the partial discharge could be on-line monitored by removing the noise signals measured by the inductance sensor on the grounding wire of a 154kV lightning arrester from the superposed signals of internal partial discharge and external corona noise measured by bushing tap coupler of the transformer.

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