500 kV 变电站简化噪声源衰减特性研究

Study on Attenuation Characteristic of Simplified Noise Sources for 500 kV Substations

摘要:

基于四川某 500 kV 变电站，将其主变压器分别简化为体声源、面声源和点声源，对噪声衰减情况进行预测分析。结果表明，采用 Cadna /A 软件和噪声导则推荐模式计算的噪声声压级吻合良好，距体源、面源、点源相同距离处采用软件计算的噪声声压级差异较小，最大差值仅为 0.9 dB( A) ;在近声场( L≤5 m) ，体源噪声衰减最慢，面源其次，点源衰减最快，L( 距声源距离) 相同时，声压级从大到小依次为体源、面源、点源;而在远声场( L≥35 m) ，各声源衰减 规律一致，声压级从大到小依次为点源、面源、体源。从机理上阐明了变电站噪声预测工作中的声源简化差异问题，具有很强的指导意义。

Abstract:

The main transformer is simplified as a volume source，area source and point source respectively to analyze the attenuation characteristic based on a 500 kV substation in Sichuan province． The result indicates that the calculated noise levels of software Cadna /A highly tally with the theoretical formulas，and the difference among three kinds of simplified noise sources at the same distance is as small as just 0． 9 dB( A) ．In the near sound field，attenuation rate of volume source is the slowest， the following is area source ( L≤5m) ，and the fastest is point source，so that the sound pressure level of volume source is the highest，the following is area source，and the lowest is point source when L ( distance from the source) is the same from the sources． However，in the far sound field ( L≥35m) ，three noise sources perform accordantly in terms of attenuation discipline，and the sound pressure level of point source is the highest，the following is area source，and the lowest is volume source．The divergence of simplified noise sources is explained form the mechanism，which is highly instructive for substation noise prediction．