随着我国“双碳”战略的实施，特/高压直流输电系统作为新能源消纳的重要技术手段得到了大量应用。电力电容器作为滤波和无功补偿的关键设备被广泛用于特/高压直流输电系统中，其产生的低频振动及噪声给换流站环保达标带来了严峻挑战。为有效降低电力电容器低频振动及噪声向外排放，从加载交变电压的心子所受电场力出发，理论推导了心子在加载基频电压和高次谐波电压时所受电场力的时/频域分布特性，并以此作为心子的激励开展了电力电容器在电场力作用下的振动特性仿真。依据电容器在电场力作用下的振动特性，提出了一种用于电力电容器本体降噪的低刚度隔振系统设计，仿真研究了低刚度隔振器的低频振动隔离性能，并结合声学有限元对比研究了未嵌入/嵌入低刚度隔振系统时电力电容器的低频噪声辐射特性。研究结果表明，除500 Hz频率点外，提出的低刚度隔振系统能在100 Hz、200 Hz、600 Hz、700 Hz和800 Hz等频率点高效降低了电力电容器低频噪声排放，可有效实现电力电容器的本体降噪性能。

With the implementation of China′s “dual carbon” strategy, ultra/high-voltage direct current transmission system has been widely applied as an important technical means for new energy consumption. The power capacitors, as key devices for filtering and reactive power compensation, are widely used in ultra/high-voltage direct current transmission systems. However, the low-frequency vibrations and noises of power capacitors pose a serious challenge to the environmental standards of converter stations. To reduce the emission of low-frequency vibrations and noises of power capacitors, the electric field force of electric core under AC voltage is investigated for a start, and then the time/frequency domain distribution characteristics of the electric field force on electric core under both fundamental frequency voltage and higher harmonic voltage are theoretically derived. Based on this, the excitation of the electric core is used to simulate the vibration characteristics of the power capacitor under electric field force. Based on the vibration characteristics of power capacitors under electric field force, a low stiffness vibration isolation system design for noise reduction of power capacitor body is proposed, and the low-frequency vibration isolation performance of the low stiffness vibration isolator is simulated and studied. Furthermore, combined with acoustic finite element analysis, the comparative study is conducted on the low-frequency noise radiation characteristics of power capacitors are compared with and without the low stiffness vibration isolation system embedded. The results show that the proposed low stiffness vibration isolation system can effectively reduce the low- frequency noise emissions at frequencies 100 Hz, 200 Hz, 600 Hz, 700 Hz and 800 Hz in spite of 500 Hz, which indicate that the noise reduction of power capacitor body can be achieved efficiently.