换流站电力电容器塔的噪声预测

Sound prediction for power capacitor towers at converter stations

电力电容器塔是换流站的主要噪声源之一,因单元数量多、声波相干性作用复杂、单元间相互遮挡等,难以对其进行准确的噪声预测。该文通过实验方法获得电容器单元的表面振动加速度,采用边界元模型计算电容器塔辐射的噪声,并运用噪声预测评估软件对电容器塔进行建模,包括完整建模和简化为点声源、线声源及工业建筑物的建模。研究表明:边界元模型和完整建模方法能够考虑到电容器单元的声辐射指向性和单元间的遮挡作用,前者还能考虑到单元内不同壁面处相位差、单元间声波相干性的影响,比后者能较好地反映声场分布特点;简化点声源和线声源的方法预测结果相近,均无指向性且预测的总声功率偏高;简化工业建筑物的方法考虑了电容器塔的声辐射指向性和遮挡作用,方法简单且能较准确地预测总声功率。

Power capacitor towers are one of the main noise sources of converter stations.It’s difficult to accurately predict its noise emission owing to numerous units,complex acoustic coherence effects,and mutual shielding.First,the paper obtains the surface vibration acceleration of a capacitor unit from experiment.Then,the noise radiated by a capacitor tower is calculated by boundary element method(BEM).Finally,the tower is modeled using the noise prediction software,including detailed and simplified modeling.The research shows that both the BEM and the detailed modeling consider the sound radiation directivity of a capacitor unit and the shielding effects between units.The former,which also considers the effects of the phase difference at different walls of a unit and the acoustic coherence between units,can better reflect the soundfield distribution than the latter.The simplified point source modeling has similar prediction results as that of the line source modeling.Both have no directivity and over-estimated total sound power.The simplified industrial building modeling,which considers the sound directivity and shielding effects of the capacitor tower,is simple and can predict the total sound power accurately.