Study On Evaluation Method Of Sound Quality Improvement Effect Of Noise Control Measures On Substation Noise

In order to evaluate and control scientifically the influence of substation noise which has drawn considerable public attention,this study conducted an on-site sampling and characteristic analysis of noise from 110-500 kV substations,selected annoyance as the evaluation index of sound quality and performed a subjective evaluation experiment on substation noise.As a consequence,not only were the main acoustic factors affecting sound quality of substation noise clarified,but also the evaluation method of sound quality of substation noise and the corresponding annoyance prediction model were established.Moreover,the noise samples after noise reduction were obtained by filtering the original noise samples according to noise reduction in each frequency band of substation noise control measures predicted by LMS Virtual.Lab software,and then sound quality improvement effect of different sound barriers were evaluated quantitatively by subjective evaluation experiment and subjective annoyance prediction model.Finally,the evaluation method of sound quality improvement effect of substation noise control measures was put forward.The results showed that A-weighted sound pressure level(LAeq),loudness level(LN)and loudness(N)had a good fitting effect(R2>0.9)for substation noise annoyance,indicating that each of the three acoustic parameters could be a more appropriate evaluation index of substation noise annoyance.Substation noise annoyance prediction model which was established on the basis of improved Zwicker's psychoacoustic annoyance(PA')had not only a higher coefficient of determination(R2>0.9)but also a higher prediction accuracy(namely,the linear regression slope between the model predictions and the experimental values was close to 1),thus it could be used as the optimal model for substation noise annoyance prediction.In addition,the same sound barriers had different sound quality improvement effect on tansformer noise at different locations,and sound quality improvement effect of sound barriers with better noise reduction effect may not be necessarily better.Therefore,it is more appropriate to optimize noise control measures according to sound quality improvement.The relative magnitude of noise annoyance gained by the subjective evaluation experiment and the subjective annoyance prediction model at the concerned points before and after the implementation of the noise barrier was relatively consistent,suggesting that both of the two methods were suitable for evaluating the sound quality improvement effect of the typical noise control measures of the substation.The results in this study are of great significance to assess the influence of substation noise and optimize substation noise control measures.Meanwhile,they can provide strong technical support for substation construction in China from an environmental perspective.