The AC filter capacitor of the converter station is the main noise source of AC filter field due to its large quantity

big dimension and pass of large harmonic current. In this paper

the sound level meter and PULSE audio analyzer are adopted on the basis of studying the field situation of AC filter site of converter station in detail

to test the sound pressure and the narrow band spectrum of characteristic frequency for the filter capacitor bank of the converter station. It is shown by the test result that the sound level at the bushing side of the capacitor frame is higher than that of the side of the side face. The noise radiates longitudinally mainly along the capacitor unit and the noise frequency spectrum on both bushing and the side face side of the capacitor device is similar. The maximum frequency of the radiation noise of capacitor is related to the number of the filtered harmonics. The study result can provide basic data support for the noise reduction design and improvement of the capacitor.