正极性单点电晕放电可听噪声时域波形拟合及分析

Analysis and Fitting of the Time-domain Waveform of the Audible Noise Caused by Single Positive Corona Source on the Conductor

基于实验室搭建的可听噪声时域测试平台,获得了正极性单点电晕放电产生可听噪声的时域波形。根据可听噪声时域波形的脉冲特性,提出了采用分段双指数函数来拟合单个可听噪声时域脉冲波形的经验波形,通过在时域和频域上对拟合结果和测量结果的对比研究,验证了所提出拟合波形的合理性。最后,基于长时间可听噪声时域测试结果分析了不同电压下分段双指数函数中的拟合参数和可听噪声波形参数的统计特性。实验结果表明,由于电晕放电的随机性,在同一电压下脉冲波形参数及波形拟合参数具有较大的波动性;可听噪声脉冲的时间间隔随着电压的增加有所降低,而脉冲宽度及视在持续时间在不同电压下变化不大。

The time-domain waveform of audible noise caused by the discharge of single positive corona source is obtained by the time-domain test platform set up in the laboratory.According to the pulse characteristic of time-domain waveform of audible noise it is proposed to utilize segmented double-exponential function to fit single time-domain pulse waveform of single audible noise to obtain empirical waveform,and through the comparative research on fitting results and measured results in time-domain and frequency-domain the reasonableness of the proposed method of the fitted waveform is validated.Finally,based on the measured results of long-term audible noise in time-domain the statistical characteristics of fitting parameters of the segmented double-exponential function under different voltages and that of waveform parameters of audible noise.Experimental results show that due to the randomness of corona discharge,the pulse waveform parameters and waveform fitting parameters evidently fluctuate under the same voltage; the time interval of audible noise pulse decreased with the increase of the applied voltage,however the pulse width and its apparent duration slightly varies under different voltages.