The Application Of Virtual Sound Barrier In Reducing Low Frequency Noise Of Power Transformer

With the rapid development of social economy, the density of power load is rise.To ensure the safety and reliability of power supply, a lot of transformer substation are constructed in densely populated areas.But the power supply enterprises is puzzled by the noise problem of running transformer, disputes Caused by the transformer noise increase year by year. Because the low-frequency noise of transformer decays slowly, the treatment effect of using acoustic is relatively poor, the noise level of environmental is hard to reach requirements of area.Started from the analysis of the substation noises, this paper study the noise generation mechanism of transformer、reactor、indoor fan,the results show that transformers are the primary noise source while the others are secondary sources that can be ignored. Because the low frequency noise of transformer is difficult to control, the active noise control strategy is put forward, the virtual noise barrier system id designed,this paper completes 18 channel input, 16 channel output of multi-channel active controller and the development of the peripheral circuit, a reliable hardware platform and software algorithm is set up.And the reduction effect of low frequency noise is verified in a laboratory.Finally we field measure the sound field distribution of the 220 kv guangxing substation,build the virtual noise barrier system according to the field distribution of guangxing substation. In order to achieve the best effect of noise reduction,we debug the distance of between the error microphone and the second source. After the substation noise was measured,the results show that noise reduction performance of the virtual noise barrier is basic consistent with glass windows in Low frequency band.At the same time the virtual noise barrier system is beneficial to natural ventilation of transformer. this paper put forward active noise control technology in order to control the general noises within the national regulation,a quiet and comfortable living environment for the surrounding residents is offered.