含高比例谐波电磁力驱动下换流站滤波设备噪声机理与抑制措施

Filtering devices vibrate under the action of electromagnetic force containing high proportion of harmonics, and are one of the main audible noise sources of converter stations. It is meaningful to propose noise reduction measures for power capacitors and dry-type air-core reactors based on the investigation of the vibration and audible noise generation mechanism. This project starts with investigation of the dynamic characteristics of two-body vibration model, and the relations of electromagnetic force, natural vibration of structures and vibration responding are analyzed. By studying the continuum model of capacitor and vibration characteristics of reactor, the mechanism of vibration excitation, transferring and noise radiation under the action of electromagnetic force containing high proportion of harmonics is explored. The contribution of surface vibration to audible noise is analyzed, vibration and noise reduction measure based on the theory of vibration tuning control for both filtering capacitors and reactors is investigated and verified, along with its mechanical factor, mounting position, materials and structure to noise reduction effect. With the purpose of global noise reduction for filtering area in converter stations, sound source modeling method of filtering devices is built up referring to the noise characteristics of filtering devices, and based on offset interference of sound waves generated by modeled sources, the sound field of filtering area in converter stations is optimized. This project will enhance the fundamental theory of filtering devices stacks noise radiation under the action of electromagnetic force containing high proportion of harmonics in HVDC converter stations, and will be of great significance for the solution of the noise pollution of our UHVDC projects.

滤波设备在含高比例谐波电磁力驱动下产生振动并辐射噪声，是换流站中最主要的可听噪声源之一，研究滤波设备中电容器及电抗器的振动噪声产生机理及相应的抑制措施具有重要意义。本项目从抽象的两体振动模型动力学特性研究出发，探究滤波设备的电磁力、固有机械振动特性和振动响应之间的内在关系；通过电容器心子连续体模型及电抗器振动特性，研究含高比例谐波电磁力驱动下滤波设备振动产生与传递过程；分析设备表面振动传递路径及其对整体辐射噪声的贡献，探究振动调谐器安装位置、机械参数、所用材料及其结构等对辐射噪声的影响规律，研究并验证用于滤波设备本体减振降噪的振动调谐控制方法；对于换流站滤波场区域噪声抑制，根据滤波设备噪声特性构建其声源模化方法，利用模化后声源研究基于声波相消干涉作用的滤波场区域声场优化措施。本研究对完善含高比例谐波电磁力驱动下换流站滤波设备辐射噪声机理，解决我国特高压直流输电工程噪声污染问题具有重要意义。

滤波设备在含高比例谐波电磁力驱动下产生振动并辐射噪声，是换流站中最主要的可听噪声源之一，研究滤波设备中电容器及电抗器的振动噪声产生机理及相应的抑制措施具有重要意义。本项目充分考虑了滤波设备电磁力与振动的耦合作用，采用最小作用量原理对电容器的振动与电场进行统一地分析，构建出从滤波电容器单元基本结构抽象而来的两体振动模型，深入解释了电容器振动与噪声的多倍频特性。通过振动测量实验获得了电容器单元与干式空心电抗器在不同谐波频率下的振动形态，并分析了振动的来源与传递特性。结果表明，电容器单元的底面呈现整体同步振动形态，而宽侧面和窄侧面振动呈现波动形态，电容器内部心子振动先传递到底面，底面振动通过棱边传递到宽侧面和窄侧面；电抗器的包封同样呈现波动形态，主要受其模态特性主导。根据电容器单元及干式空心电抗器噪声的影响因素及影响规律，提出了针对电容器单元的刚度调谐和质量调谐减振降噪措施，在特定谐波组合下可使噪声下降7.8~14dB(A)；提出了针对电抗器的分布式动力吸振器减振降噪措施；基于边界元法仿真研究了多台电容器噪声的干涉现象及其影响因素，提出了基于圆弧阵列布置和中心对称布置的电容器组声场优化措施，可使声压敏感目标调控区域声压级降低9.6dB，实现了对整个滤波场区域的声场调控。本研究对完善含高比例谐波电磁力驱动下换流站滤波设备辐射噪声机理，解决我国特高压直流输电工程噪声污染问题具有重要意义。