Research on Low Frequency Line Spectrum Characteristics and Control Effect of 220kV Indoor Substation Sound Source

Low frequency noise has always been a difficult problem in the fields of acoustics and noise control. Because conventional A-weighted sound pressure levels cannot reflect low-frequency contributions, in order to understand the low-frequency noise characteristics of substations and better control the impact of substation noise on the surrounding environment, this article selected three typical 220kV indoor substations for low-frequency line spectrum testing and analysis. The sound source characteristics, noise reduction device effects, and boundary noise characteristics of three substations were analyzed separately. The results showed that the sound pressure level of the 220kV transformer was between 69.5dB (A) and 76.4 dB (A), and the sound energy was mainly concentrated at 100Hz and its harmonics, with different transformer peak frequencies. The peak of the noise spectrum at the factory boundary is at 100Hz and 200Hz, but after noise reduction and distance attenuation, it has been significantly reduced, and can be reduced by more than 20dB compared to the sound source.