【摘要】 采用小波时频分析的方法对发生在气体绝缘金属开关设备(GIS)内部局部放电而激发的电磁波和外界的电晕干扰进行了分析,讨论了区分和识别外部和内部放电及外界干扰的可能性。在单一信号存在的情况下,发生在GIS变电所的电晕干扰一般在130MHz以下,频宽小于70MHz,而内部放电激发的电磁波信号无论何种缺陷以及类型如何,其频宽至少是电晕干扰的2倍以上,所以,从信号的带宽上可以判别是内部放电还是外部干扰。当电晕和放电信号共存时,可以通过信号的带宽和信号到达的前沿综合判断。结果表明,该方法简单有效,可以满足在线检测中信号识别的要求。更多还原

【Abstract】 The electromagnetic wave excitated by partial discharge inside GIS(Gas-Insulated Switch-gear) and external corona-generated interference are analyzed using the wavelet transform in time-frequency-domain.The feasibility of distinguishing between internal discharge and exte rnal interference is discussed.When only single signal exists,the frequency of corona-generated interference in substation is commonly under 130 MHz with less than 70 MHz bandwidth.However,the bandwidth of whatever electro-magnetic wave excited by partial discharge inside GIS is at least double times of that of corona-generated interference.When both signals exist,they can be synthetically distinguished by band-width and advancing front.The result shows that the method is easy and effective,meeting the requirements of signal distinguish for on-line monitoring.更多还原