强干扰环境下外加故障诊断信号的选取与检测

利用外加信号对电气设备进行在线故障诊断、绝缘监视和参数监测的技术在近几年得到了较快的发展。由于与电气设备本身的高电压、大电流相比,外加信号的量值很小、能量和信噪比都很低,所以外加信号的加入和检出是这些技术应用的主要难点。在分析的基础上,提出了外加信号应不同于任何一种固有信号选取的原则,导出了一种适合于数字式处理、能够从强干扰环境下灵敏可靠地检测出外加信号的处理方法,给出了应用的实例。

Detection of injected diagnosis signal in high interference condition

The signal injection based techniques of on-line fault diagnosis,insulation monitoring,and parameter measurement of electrical devices have been developed quickly in recent years.Compared with the high voltage and large current of the primary equipment,the magnitude of signal voltage and current is considerablely small.Detection of the small signal in the high interference condition is the main technical barrier to use the technique.The consideration and principle to select the injecting signal is discussed in the paper.A method,which is suitable for digital processing and can easily separate out the injected signals from high interference condition,is deduced.Application example of the technique is presented.