Filter capacitors are among the most serious noise sources in HVDC converter stations, and there are still no satisfactory noise reduction measures. This paper proposes the use of the mass tuning (MT) method to adjust the vibration frequency response characteristics and to realize vibration control and noise reduction. First, the theoretical model of the MT structure is developed based on continuum mechanics. Based on the theoretical model, it is revealed that inserting an MT component into the capacitor element package will cause a decrease in the resonant frequencies and antiresonant frequencies. Furthermore, the movement degree of the resonant frequencies increases as the position of the MT component becomes closer to the package end, while the movement degree of the antiresonant frequency is the largest when the MT component is located in the middle of the package model. The vibrations and the noise levels of an example MT capacitor are then compared with the results of an original capacitor. The comparison results show that the MT scheme designed in this paper can achieve a noise reduction effect of 12–15 dB(A). The proposed reduction method is proven to be both effective and efficient.

中文翻译：

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高压直流滤波电容器振动和可听噪声的质量调谐消减方法

滤波电容器是高压直流换流站最严重的噪声源之一，目前尚无令人满意的降噪措施。本文提出了利用质量调谐（MT）方法来调整振动频率响应特性，实现振动控制和降噪。首先，基于连续介质力学建立了MT结构的理论模型。根据理论模型可知，在电容元件封装中插入MT元件会导致谐振频率和反谐振频率降低。此外，随着MT元件的位置靠近封装端，谐振频率的移动程度增加，而当MT元件位于封装模型的中间时，反谐振频率的移动程度最大。然后将示例 MT 电容器的振动和噪声水平与原始电容器的结果进行比较。对比结果表明，本文设计的MT方案可以达到12-15 dB(A)的降噪效果。所提出的减少方法被证明既有效又高效。