采用TEV传感器的开关柜局部放电检测技术研究与实现

Research and Implementation of Partial Discharge in HV Switchgear Using TEV Sensor

分析了开关柜内发生局部放电时柜体表面产生暂态地电压原理及TEV传感器设计原理。依据设计原理研制了一种TEV传感器，运用TEV传感器对3种典型开关柜缺陷模型进行了试验研究。并对放大检波前后的TEV信号进行了分析。基于所设计的TEV传感器、放大检波电路以及超声波法研制了一套开关柜局部放电检测装置，并运用该装置对多个变电站进行了实测。结果表明：TEV原始信号幅值低于100mV，能量分布在3～200MHz之间；所设计的放大检波电路提高了原始TEV信号的信噪比，降低了采集难度，试验研究和现场测试验证了该套检测装置的有效性。

The mechanism of transient earth voltages（TEV）aroused by partial discharge in switchgears and the design mechanism of the TEV sensor are analyzed, the TEV sensor is designed according to its design mechanism and is used to record the TEV information corresponding to three typica PD models in HV switchgears. The origi- nal and after-amplifying-modulating TEV signal is analyzed. Detection system is developed combining with TEV sensor, amplifier demodulation and AE method. The system has been tested in several substations. The results show that, the amplitude of TEV original signal is lower than 100 mV, the energy distribution is lied in the frequency of 3 MHz to 200 MHz. The designed amplification demodulation circuit has improved the SNR and reduced the difficulty of collecting： Experimental research and field application verify the effectiveness of the system.