Apple grove 750 KV project - two year statistical analysis of audible noise from conductors at 775 KV and ambient noise data

Kolcio, N.; DiPlacido, J. N.; Dietrich, F.M.

doi:10.1109/t-pas.1977.32366

Cited by 15 publications

(4 citation statements)

References 7 publications

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“…It suggests that water droplets on the conductor are the reason for noise generation. The ambient noise level at 100 Hz is higher than 200 Hz because the low‐frequency noise with the longer wavelength can be propagated easier and further than high‐frequency noise [44]. Dry conditions also increased A‐weighted overall sound pressure level and 200 Hz noise level above the background—likely because of small surface defects like scratches on the conductor causing corona discharge.…”

Section: Results and Analysismentioning

confidence: 99%

Experimental verification of the potential of superhydrophobic surfaces in reducing audible noise on HVAC overhead line conductors

Zhang

Cotton

et al. 2022

High Voltage

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Overhead line conductors can generate audible noise across a wide frequency spectrum as a result of elevated electric fields at the conductor surface. Such fields are enhanced by the presence of surface defects, insects, water drops and pollution. Within this paper, the impact of a superhydrophobic coating on the audible noise produced by an overhead line conductor is examined. Noise levels from a conductor coated with a superhydrophobic coating were compared to those from a bare conductor in a semi‐anechoic chamber. The conductors were energised at voltages to provide surface electric fields ranging from 6 kV/cm to 21 kV/cm (rms). With a continuous water spray system depositing droplets on the conductor surface, the frequency domain sound pressure level, overall sound pressure levels and corona discharge magnitude were measured. It is demonstrated that the use of a superhydrophobic coating reduced audible noise levels and corona discharge magnitude, especially at electric fields above 14 kV/cm. The image analysis suggests that the water drop size distribution and the position of surface droplets on the conductor circumference play an important role in the magnitude of audible noise.

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Section: Results and Analysismentioning

confidence: 99%

Experimental verification of the potential of superhydrophobic surfaces in reducing audible noise on HVAC overhead line conductors

Zhang

Cotton

et al. 2022

High Voltage

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“…In the seventies and eighties of the last century, American Electric Power Service Corporation (AEP, United States) statistically analyzed the AN test data of three test lines for nearly 2 years at Apple Grove 750‐kV Test Project and obtained the statistical values [19]. Then AEP made a statistical analysis of the AN of 765‐kV lines operating at different voltages and compared those with the Apple Grove 750‐kV test line.…”

Section: Introductionmentioning

confidence: 99%

“…These lines are generally located in plain and low-altitude areas, and the AN was mainly measured in the one-octave band, with the pure-tone effect not analyzed. Except that the Korean 765-kV transmission line uses the same 6-bundle conductor as our country, the others are 4bundle conductors [19][20][21][22][23]. Bonneville Power Administration (BPA, United States) has conducted long-term tests on AN and RI of two 500-kV double-circuit transmission lines with an altitude of 1935 and 277 m, and then compared the difference of statistical values to study the altitude correction method [24].…”

Section: Introductionmentioning

confidence: 99%

Audible noise analysis of 750‐kV AC transmission line in high‐altitude area under different weather

Zhang

Xu²,

Li³

et al. 2023

IET Generation Trans & Dist

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In order to build UHV AC transmission lines at high altitudes, it is necessary to analyze the audible noise (AN) characteristics of the existing EHV transmission lines at high-altitude areas to guide the design. The typical test data of AN for 750-kV single-circuit transmission lines measured at the Guanting long-term observation station, located at an altitude of 1854 m, were collected. Two methods of sorting the test data of AN and extracting valid data were given. Then the levels of AN under different weather conditions were analyzed, which showed that AN was raised with the increase of instantaneous rainfall and snowfall. Typical frequency spectrums of AN under different weather were also obtained, the pure tone at 100 Hz was more prominent under rainy and snowy weather, and the pure-tone oscillation attenuated at different positions. The statistical results and the calculated difference of AN over 5.5 h with continuous rainfall were obtained. For the 750-kV transmission line in the quiet plateau areas, the calculated difference between AN during rainy days and fair weather can be taken as 25 dB, and the calculated value of the altitude correction coefficient of 2.85 dB/1000 m is better consistent with the measured value.

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“…Accompanied with the corona discharge, several unwanted effects, such as radio interference, audible noise, ionized fields and corona loss, may appear around the transmission lines [1][2][3]. Authors Among these associated problems, the audible noise can be directly perceived by the surrounding people and has become one of decisive factors in the design of HVDC and HVAC transmission lines since the operation of transmission voltages of 500kV and above [4][5][6][7][8][9][10][11][12][13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Time-domain and frequency-domain characteristics of audible noise from single corona source

Cui

et al. 2014

2014 International Conference on Power System Technology

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In this paper, the time-domain measurement method for audible noise is employed to study the time and frequency domains characteristics of audible noise generated by single corona discharge under DC and AC voltage in a coaxial geometry. The results show that in time-domain the audible noise from positive and negative corona discharge both consist of a series of random sound pressure pulses and the amplitudes of sound pressure pulses from positive corona discharge are larger than those from negative corona discharge. As for the audible noise from AC corona discharge in the test, it has a periodic component with a 50Hz fundamental frequency accompanied by sound pressure pulse trains mainly near the negative peaks of AC voltage. When the applied voltage is further increased, sound pressure pulses may be generated at the positive half-cycle. The asymmetrical waveforms in positive and negative half-cycle of AC voltage may attribute to the influence of the space charges. Besides, the discrete wavelet transform (DWT) is used to analyze the detailed characteristics and the difference of corona-generated noise and the background noise. Furthermore, the frequency-domain characteristics of audible noise from DC and AC corona are analyzed based on the time-domain results. This presented work hopefully will be a useful reference for further theoretical studies of the audible noise caused by corona discharge. IndexTerms-audible noise, time-domain and frequency-domain characteristics, single corona source, AC and DC corona discharge

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Apple grove 750 KV project - two year statistical analysis of audible noise from conductors at 775 KV and ambient noise data

Cited by 15 publications

References 7 publications

Experimental verification of the potential of superhydrophobic surfaces in reducing audible noise on HVAC overhead line conductors

Experimental verification of the potential of superhydrophobic surfaces in reducing audible noise on HVAC overhead line conductors

Audible noise analysis of 750‐kV AC transmission line in high‐altitude area under different weather

Time-domain and frequency-domain characteristics of audible noise from single corona source

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