Sound pressure level of the audible noise from single positive corona source based on the time domain measurement results

The time domain results of the audible noise can be used in the evaluation of the noise level directly at present, therefore, we put forward a method for transferring time domain results into the sound pressure level in frequency domain based on the principle of sound level meter and randomness nature of the audible noise from DC corona discharge. In this method, the power spectrum is used to calculate sound pressure values and the time weighting, and to realize the A-weighted analysis of the audible noise signal. The validity of the presented method is demonstrated through comparing with the calculated results based on Labview program. Moreover, the method is applied to analyze the characteristics of audible noise caused by single corona source under a positive voltage. The frequency domain characteristics and the sound pressure level characteristics of the audible noise are analyzed. The result reveals that the level of sound pressure of the audible noise generated from single-point DC corona in discharging increases as the voltage increases, which is between 20 Hz and 20 kHz. The A-weighted sound pressure level of corona noise at high frequency (above 1 kHz) is higher. The results can lay a foundation for the future research on characteristics of audible noise produced by the corona discharge.