Construction Of The Identification And Assessment System Of The Noise From110kV,220kV Substation And Control Techniques Research On The Noise

In recent years, with the development of national economy, some new residentialareas has been built near the substations，and some of the new substations sometimesneed be built close to a residential area or in a residential area. The noise of thesubstations has a greater impact on the surrounding residents.Firstly, typical110kV,220kV substations chosen from many substations areanalyzed by the noise source identification technology based on acoustic imagingtechnology. By the analysis, the position of the noise sound and the reasons of the noiseare found out. The main noise sources of110kV,220kV substations are the transformerand its subsidiaries cooling equipment. Spectral characteristic of the noise islow-frequency noise prominent band noise. The frequency of the peak is100Hz、200Hz、300Hz、400Hz or600Hz。Secondly, typical substations chosen were distributed and monitored. The transformercooling equipment and its subsidiaries are regarded as point sources and surface sourcesto made distance and height attenuation prediction. And the predicted values arevalidated with experimental results. Verification results show that in1-10m、10-20mand20-30m away from the transformer, the average errors between experimentalresults and the values predicted by the surface source model are0.3dB（A）,0.8dB（A）and1.7dB（A）, and the average error rates are0.5%,1.5%and3.7%. the average errorsbetween experimental results and the values predicted by the point source model are5.2dB（A）、6.1dB（A）and5.2dB（A）,and the average error rates are8.8%、12.0%�'�11.6%. In1-15m height from the transformer, the average error betweenexperimental results and the values predicted by the surface source model is0.9dB(A),and the average error rate is1.7%. The maximum error and The maximum error rate are1.7dB(A) and3.2%. The average error between experimental results and the valuespredicted by the point source model is7.3dB(A) and the average error rate is13.9%.The maximum error and The maximum error rate are8.6dB(A) and16.4%. So in1m-30m away from the transformer and1m-15m height from the transformer, thesurface source model preferably measured results for the oil－immersed air－cooledtransformers. Using surface source model is more realistic. By the research of the noise source identification technology based on acousticimaging technology and the prediction model, the general steps of the system of thesubstation noise environmental impact identification and assessment are determined.Finally, by analyzing various substation noise control measures and considering thebasic principles of noise control, noise control measures were identified. Combined withan An-qing110kV substation noise control instance, based on the original transformerroom, Insulation and absorption control measures and impedance composite muffleraffiliated cavity were used to control the substation noise. The sound absorptionconstructions are installed in the room, and acoustic doors and windows are installed,and the impedance composite mufflers affiliated the cavity are installed out of the airvents. The factory boundary noise has decreased from65.4dB(A) to43.8dB (A) andmet the requirement of less than45dB (A).