基于感应滤波技术的换流变压器降噪方法

硅钢片磁致伸缩是引起变压器振动噪声的主要原因,而换流变压器中的谐波可加剧硅钢片磁致伸缩,从而导致变压器噪声增大.本文首先建立了四柱单相换流变压器原理样机铁心的各阶振态模型,讨论了谐波磁通对硅钢片磁致伸缩的影响,并从声学角度论证了谐波磁通与变压器噪声的相关性.然后,基于感应滤波技术的基本原理,从理论上分析了其降噪的可行性.最后,搭建了12脉波整流系统实验平台,实验数据表明感应滤波技术能有效地降低换流变压器的振动噪声,且降噪效果优于传统的滤波方法.
Transformer vibration and noise are mainly caused by the magnetostriction of silicon steel sheets. Since the magnetostriction of silicon steel sheets can be aggravated by the harmonic,the vibration and noise of transformer will be more excited if harmonic flux is flowed within transformer. In this paper,the vibration mode of the core of a four-column single-phase converter transformer prototype was built,and the influence of harmonic flux on the magnetostriction of silicon steel sheets were discussed. From the view point of acoustics,the relevance of harmonic flux and noise of transformer was verified. Second,based on the basic principle of inductive filtering method,the noise reduction feasibility of this method was theoretically analyzed. Finally,one 12 pulses rectifier system was built. The experimental data shows that the converter transformer noise can be effectively suppressed by using the inductive filtering method,and noise reduction performance of this filtering method is more preferable,compared with other traditional filtering methods.