Filter capacitor

as one of the main noise sources of converter station

has significant impact on the noise around the converter station. In order to accurately master the noise characteristics of the filter capacitor and eliminate the interference with other sound source during field measurement

a scaled capacitor is made up of capacitor unit and its noise is measured in a semi-anechoic chamber. The spectral characteristics of the noise is summarized and the spatial distribution characteristic is discussed. It is found that the noise radiation of the scaled capacitor possesses obvious directional and symmetrical performance. Furthermore

the influence factors of noise characteristics are analyzed by changing the loading conditions and arrangement mode. The results show that under the same loading condition the sound pressure level (SPL) on the non bushing side of the device in flat configuration will be higher. The SPL is reduced approximately by 3 dB when the number of capacitor units are reduced by half

but the SPL at the non bushing side will be saturated. When the bottom spacing or the side spacing are about 3/4 of the acoustic wavelength

there is a minimum of the corresponding frequency SPL in the direction of bushing side direction of the device. The study result has provided basic data support for the noise assessment and reduction design and has reference significance.