摘要
变压器噪声是变电站主要噪声来源之一,研究变压器噪声对合理评估变电站噪声水平及对变压器降噪分析具有重要意义。从变压器噪声产生机理入手,分析变压器铁心和绕组的电磁振动噪声,建立了其电磁-结构-声场有限元模型。通过瞬态电磁场分析,并基于虚位移法得到铁心和绕组所受电磁力的时域波形,采用FFT变换对结果进行后处理获取电磁力的主要谐波分量大小,将其作为结构谐响应分析的激励源,通过频域内的振动分析得到铁心和绕组表面各节点的振动位移,并将其作为变压器声场分析的边界条件,进一步求解变压器声场模型,分析得到变压器周围空间场点在噪声集中频率100 Hz和200 Hz上的声压级,并与实测值进行对比分析,验证了该模型的可行性,可为变压器噪声预测提供理论依据和计算方法。
The noise of transformer is one of the main noise sources in substations. The analysis of the transformer noise is of vital importance for noise prediction and control. In this paper, a magneto-mechanicalacoustic coupled finite element model is presented through studying the transformer noise generating mechanism and analyzing the electromagnetic vibration noise of the transformer core and winding. First,the flux density is calculated by transient electromagnetic field analysis and the electromagnetic forces of the core and winding are calculated using the virtual displacement method. Then,FFT analysis is carried out to obtain the main harmonics of the electromagnetic forces which are set as the excitation sources for structure vibration harmonic response analysis. By vibration analysis in the frequency domain,the vibration displacements of each point on the surface of transformer core and winding are obtained and the results are set as the boundary conditions for acoustic field analysis. Finally,the sound pressure levels of noise of 100 Hz and 200 Hz around the transformer space are calculated by solving the acoustic model and compared to the measured data to confirm the validity of the proposed method. Results show that the model is available for transformer noise prediction.
出处
《电工技术学报》
EI
CSCD
北大核心
2016年第15期81-88,共8页
Transactions of China Electrotechnical Society
基金
国家电网公司大电网重大专项资助项目(GYW17201300115)
关键词
变压器噪声
电磁-结构-声场模型
有限元法
FFT
电磁力谐波
Transformer noise
magneto-mechanical-acoustic coupled model
finite element method
FFT
electromagnetic force harmonic
