基于全相FFT的电力变压器噪声衰减模型

Attenuation Model of Transformer Noise Based on All-Phase FFT

分析变压器噪声信号的频域特性和衰减模型,有利于变电站有源噪声控制技术的研究。对某变压器噪声信号进行全相FFT频谱分析,得到其频域特性曲线。由频谱图可以看出,该变压器噪声以100 Hz为基频,并在基频处噪声声压级达到峰值。首先利用全相FFT谱分析法处理各参考点噪声信号,得到倍频带声压级。再结合变电站各参数,建立声衰减模型,即可计算预测点声衰减量并合成其A声级,进而绘制出变电站噪声A声级及100 Hz声压级分布图。结合全相FFT的噪声衰减模型可以准确地计算出变电站的噪声分布,直观地评价变压器噪声对周边环境的影响。

It is conducive to the studies on control technologies of the soured noise in a substation that analyzing the frequency domain properties and the attenuation model of a transformer's noise signal.In this paper,the noises collected from the transformer were analyzed using the full-phase FFT spectrum,and of which the frequency domain curve was obtained.As shown in the spectrogram,the fundamental frequency of the noises was 100 Hz and at this frequency the sound pressure level corresponding to every frequency point reached its maximum.In this study the full-phase FFT spectrum was utilized to obtain the octave band sound pressure levels and to analyze the noise signal of the reference point.Then the acoustic attenuation of the set point could be calculated and the attenuation model could be built by combining the parameters of the substation.The A sound pressure level and 100 Hz sound pressure distribution could be draw.The utilization of the noise attenuation model is beneficial to calculate the substation noise distribution more accurately,what's more,to evaluate their impacts on the surroundings more directly.