• Title/Summary/Keyword: Hum Noise

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Electrical and Mechanical Noise Study of the 765kV Transmission Line (765kV 송전선로의 전기적 및 기계적 소음고찰)

  • Lee,
    • Journal of KSNVE
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    • v.6 no.1
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    • pp.89-95
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    • 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).

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An Experimental Study on the Noise and Vibration Characteristics of LCD TV Inverter (LCD TV 인버터 소음 및 진동 특성의 실험적 연구)

  • You, Chung-Jun
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.18 no.9
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    • pp.982-989
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    • 2008
  • There is a noticeable hum from the inverter board of LCD TV when in operation. In this study, we investigate the source and the characteristics of this noise for the inverter board of LCD TV using measurement of vibration and noise. Modal analysis of vibration and noise is visualized for identification of noise sources and transmission vibration. The main source of noise was the transformer of the LCD TV inverter. A noise reduction was achieved by damping the structural elements.

A study on the highway traffic noise characteristics for the design of noise barrier (방음벽 설계를 위한 고속도로 소음 특성에 관한 연구)

  • Yoon, Je-Won;Lee, Hong-Ki;Ryu, Kuk-Hyun;Kang, Huy-Man;Jang, Tae-Soon;Park, Yang-Hum
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2005.05a
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    • pp.758-761
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    • 2005
  • 본 연구에서는 고속도로 발생 소음특성을 측정하여 방음벽 설계 인자를 도출하기 위함이다. 이를 위해 인터체인지 및 영업소 인접부를 포함한 총 20개소를 선정하여 소음측정을 수행하였으며, 소음원의 주파수특성 및 일일 변동특성, 노면 종류에 따른 소음발생특성, 영업소 및 인터체인지 부근에서의 소음특성을 분석하여 방음벽 설계 인자를 도출하였다.

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Comparison of Draft Map and Digital Map for Analysis of Areas and Populations of Excessive Noise Exposure from Noise Maps (도화원도와 수치지도를 이용한 소음지도의 초과소음노출 면적 및 인구에 대한 비교 분석)

  • Yeon, Jung-Hum;Lee, Byung-Chan
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.22 no.2
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    • pp.156-162
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    • 2012
  • This paper presents differences of road traffic noise maps were generated by using the draft map and two digital maps with different versions. As a first step, the calculation of the areas of excessive noise exposure was made for the draft map and each digital map version. Subsequently, the areas of excessive noise exposure were compared so as to determine how different from each other. Then, comparison of the populations exposed to excessive noise was also conducted in the same way. It was found that the most accurate noise map was obtained when using the combination of the draft map containing all attribute information and the digital map Ver 2.0. This result indicates that more information on the height and the number of floors of the individual building is required in order to obtain more accurate population exposed to excessive noise, thus creating a more accurate noise map.

Environmental effects by corona discharge from a 765kV double circuit transmission line (765kV 2회선 송전선의 코로나 방전에 의한 환경영향 연구)

  • 김정부;이동일;신구용;양광호;안희성;구자윤
    • The Transactions of the Korean Institute of Electrical Engineers
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    • v.45 no.3
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    • pp.451-455
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    • 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.

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