为得到电晕放电辐射场的时域和频域特征,采用针板结构首先对电晕电流及其辐射场进行了理论分析,然后在此基础上对电晕电流及其辐射信号进行了实验研究。实验表明,电晕电流脉冲波形具有明显的极性效应:①负极性下先发生电晕放电,但正极性放电发生时,脉冲幅值比负极性时大;②负电晕电流脉冲波形的上升时间小于正电晕电流。实验结构不同,电晕放电辐射场的特征不同:利用第①种实验结构得到的放电波形的上升时间为十几个ns,频率分布范围集中在20~100MHz;利用第②种实验结构得到的放电波形的上升时间为几个ns,频率在200~600MHz。该结论对于下一步研究空中带高压物体的电晕放电辐射信号特征具有参考价值。
In order to get the characteristics of time domain and frequency domain of fields radiated from corona dis charge, the needle-plane electrode is employed to the theoretically analyze the corona current and its radiated signal. The experiments show that the polarity effect of the waveform of corona current pulse is distinct, 1 ) negative corona discharge occurs firstly and the pulse amplitude is shorter than that of positive corona; 2) the rising time of pulse waveform of negative corona current is smaller than that of positive corona current. The characteristics of radiation field from corona discharge is different when the experimental structure is different, the rising time of discharge waveform is about 10 ns, and the frequency range is from 20 to 100 MHz when the first experimental structure is used; the rising time of discharge waveform is several ns, and the frequency range is from 200 to 600 MHz when the second experimental structure used.