电容器噪声传播规律的研究

随着直流输电的快速发展,换流站用交流滤波电容器辐射出大量噪声,对电容器辐射传播特性的研究意义重大.本文建立了噪声特性研究试验平台,对电容器在各频率下不同电流不同距离处的噪声进行了测量,分析了电容器辐射噪声随着距离变化的规律,结合声传播理论对电容器辐射噪声的传播模式进行了辨识.结果表明,在本文测量范围内,顶面和底面辐射噪声表现为明显的球面波辐射模式,而侧面辐射噪声在距离较近时表现为柱面波传播模式,在距离较远时表现球面波传播模式.随着测量距离的加倍,电容器整体辐射噪声降低约5.4 dB,说明电容器整体辐射噪声以接近球面波的形式传播.

Study on Propagation Law of Capacitor Audible Noise

With fast development of high-voltage DC （ HVDC ） transmission system, a large amount of noise is radiated from the ae filter capacitors of converter stations and it is significant to study the propagation law of capacitor audible noise. In this paper, the test platform for the study of capacitor noise characteristics is established. The noise levels radiated from the tested capacitor are measured at several distances and different currents under each frequency, the variation relation of radiation noise of capacitor with distance is analyzed and the propagation mode of capacitor noise is identified based on the theory of sound propagation. It is shown by the result that, in the measurement range of this pa- per ,the radiation of noise from the bottom and top surfaces is obviously a spherical wave mode ,where-as the radiation of noise at side is cylindrical wave mode at near distance and is spherical wave mode at remote distance . The total noise level decreases 5.4 dB as the measurement distance doubled,indi- cating that the total radiation noise of capacitors propagates closely in the form spherical wave mode.