• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.1
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• pp.111-118
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• 2006

Relatively high noise emitted from Transformers of in-door-substation in urban area has become the target of public complaints and the frequency is on the rise in these days due to an extension of transformer installations and new establishment of substations. The noise consist of harmonics of a specific frequency of the twice of the electricity frequency(60[Hz]), which is hard to control by using the general sound proofing techniques. In this work, several effective methods were discussed for reducing the noise from a transformer, which is transmitted through explosion preventing shutter and air tunnels. By applying to the actual site, the effects of the methods were verified.

• Proceedings of the KIEE Conference
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• 1996.07b
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• pp.905-907
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• 1996

Current design standard of substation grounding systems is primarily concerned with conventional outdoor substations. But in case of 154kV substations in the nation, almost all are indoor-type GIS substations. So there became to be something not proper for application of present design standard to indoor-type substations. In this paper, as a preliminary stage of drawing-up of the grounding system design standard which concerned with in-door-type substions, issues of current design standard are mentioned and directions of improvement are also presented.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.06a
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• pp.1836-1841
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• 2000

옥내용 변전소의 셔터 및 공기풍도에 대한 흡차음 기술은 변전소의 민원소음 방지 측면에서 매우 중요한 기술이다. 변압기는 전원 주파수 60Hz의 2배 성분을 기저주파수로 하는 하모닉 성분의 소음을 발생시킨다. 본 연구에서는 실내 변압기에서 셔터를 투과하거나 공기풍도를 통해 실의로 방사되는 소음을 효과적으로 차단하는 방법론을 개발하는데 있다. 기존의 셔터의 흡/차음 성능을 개선하기 위하여 기존 셔터 앞에 흡/차음 셔터를 추가하는 장치를, 공기 풍도에는 변압기 소음주파수와 맞는 공명기를 적용하는 방법을 검토하였다. 또한, 이 장치들을 실제 현장에 적용하여 그 효과를 확인하였으며 실내변전소 변압기 소음제어용으로 유용하게 쓰일 수 있음을 확인하였다.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1542-1544
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• 2000

도심지 주택밀집지역에 설치운전중인 옥내변전소 주변압기실에서 발생되고 있는 소음은 변압기 전원주파수 2배 성분을 기저주파수로 하는 하모닉 성분의 소음을 발생시킨다. 이로 인하여 변전소 인근주민들의 변압기 소음으로 인한 민원이 발생하고 있으며 변전소의 신설이나 기존 변전소의 변압기 증설 등으로 민원발생은 점차 증가될 추세에 있다. 본 연구에서는 주변압기실에서 공기풍도나 셔터를 투과하여 실외로 전달되는 소음을 효과적으로 저감시키는 방법론을 개발하였으며 주변압기실 셔터부분에는 흡/차음셔터를, 지하 공기풍도에는 변압기 소음주파수에 맞는 공명기를 적용하는 방법을 현장에 시범 적용하여 그 효과를 입증하였다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.23 no.10
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• pp.107-114
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• 2009

Because of the increase of power demand and expansion of downtown, it is necessary to install the power transformers at the substation in the residential area. But the public complaints have increased due to the noise of the power transformers in the substation. A soundproof wall has been employed to the power transformers in the outdoor substations and a soundproof door, a soundproof shutter and soundproof equipment for wind-path has been employed to power transformers in the indoor substations in order to isolate sound propagation from the noise of the power transformers. But the noise reduction results of these methods are not satisfied. In this study, a soundproof enclosure is developed to effectively isolate sound propagation from the noise of the power transformers. The performance of the sound attenuation of the developed soundproof enclosure is verified in a 154[kV] transformer. As a result, 15[dB] sound attenuation in 120[Hz] component is achieved by applying the developed soundproof enclosure to a 154[kV] transformer.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.11
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• pp.1962-1969
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• 2008

According to the increase of power demand and expansion of downtown, it is necessary to install transformers additionally in operating substations and construct substations in residential area. But the public complaint is increased due to the transformer noise of the substation. KEPCO has used a vibration preventing pad, various soundproof walls and an encloser to transformers in outdoor substations, and a soundproof door, shutter and wind-path soundproof equipment in indoor substations to block the sound propagation of the transformers. But these noise reduction methods are not satisfied. It should be considered to reduce transformer noise itself. In this paper, we investigated core noise reduction techniques to develope a low noise transformer. The techniques to reduce core noise of the transformer are application of high permeability grain oriented silicon sheets, decrease of magnetic flux density of core, application of 6step-lap core stacking method, improvement of core binding method(binding addition, band fixing) and application of rubber damper in oder to reduce transmission of core vibration, etc.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1759-1766
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• 2008

According to the increase of power demand and expansion of downtown, it is necessary to install transformers additionally in operating substations and construct substations in residential area. But the public complaint has been increased due to the transformer noise of the substation. KEPCO has used a vibration preventing pad, various soundproof walls and an encloser to transformers in outdoor substations, and a soundproof door, shutter and wind-path soundproof equipment in indoor substations to block the sound propagation from the transformers. But these noise reduction methods are not satisfied. It should be considered to reduce transformer noise itself. In this paper, we investigated tank noise reduction techniques to develope a low noise transformer. According to the mode analysis of transformer tank, we found out characteristics and locations of noise on the tank, and it's nature vibration was also analysed. On the basis of these analysis, reinforcement equipment was installed around transformer tank, and ellipse shape tank was changed to round shape tank. The effect of noise reduction was evaluated using noise generation source.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.47-55
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• 2008

According to the increase of power demand and expansion of downtown, it is necessary to install transformers additionally in operating substations and construct substations in residential area. But the public complaint has been increased due to the transformer noise of the substation. KEPCO has used a vibration preventing pad, various soundproof walls and an enclosure to transformers in outdoor substations, and a soundproof door, shutter and wind-path soundproof equipment in indoor substations to block the sound propagation from the transformers. But these noise reduction methods are not satisfied. It should be considered to reduce transformer noise itself. To shut out sound emitted from transformers, we developed a soundproof technology that wall up reinforcing bar by steel sheet. For the practical application of it, we analyzed the vibration characteristics of a transformer tank and reduction of noise according to soundproof plate. As a result, it is confirmed that the technology can reduce 11 [dB] of transformer noise.