Study on an Audible Noise Reduction Measure for Filter Capacitors Based on Compressible Space Absorber

Filter capacitors in an HVDC converter station produce audible noise, which can be as loud as that of converter transformers and, therefore, needs to be reduced. Compressible space component (CSC) absorbers can be used to reduce the audible noise due to their broadband frequency and outstanding performance. In this paper, a mechanical model of a CSC absorber is proposed as an audible noise reduction measure for the filter capacitor in the HVDC converter station and then three CSC absorbers with different gas volumes are designed and installed at the bottoms of capacitors, respectively. Audible noise experiments of the filter capacitors with different CSC absorbers are performed and the experimental results are compared with those of a regular filter capacitor. Results indicate that the CSC absorber is a broadband absorber and is effective to reduce audible noise of the filter capacitors.