一种基于声波法的手持式高压设备局部放电故障检测仪的研究与设计

Research and Design of a Handheld High Voltage Equipment Partial Discharge Fault Detection Instrument Based on Acoustic Wave Method

受开关设备小型化设计的影响,开关设备内部局部放电现象时有发生,电力巡检部门通常采用超高频法或超声波法每年都要定期对高压开关设备局部放电情况进行巡检检测,而传统的局部放电检测设备受检测原理限制,其操作过程较为复杂,检测效率较低,费时费力,为此,本文研究并设计了一种新型声波传感器,研制了基于声波法的手持便携式局部放电检测仪,该巡检仪利用高频声波传感器采集高压开关柜内部局部放电产生的超声波信号,为了消除低频噪声和高频噪声的干扰,设计了带通滤波器滤除,将低于35kHz和高于42kHz频率的信号滤除,获取频率范围在38kHz^40kHz的局部放电产生的声波信号,并通过离散型快速傅里叶变换获得开关设备局部放电产生的声波频谱图,根据频谱图判断高压开关柜内部发生局部放电程度,经实际测试,该检测仪可以实现对带电运行中的高压开关等设备局部放电进行巡检检测,且使用方便。

Due to the influence of the miniaturization design of switchgear,the partial discharge in the switchgear often occurs.The power inspection departments usually use the ultra-high frequency method or the ultrasonic method to conduct regular inspection of the partial discharge of high voltage switchgear every year.Therefore,this paper studies and designs a new type of acoustic sensor,develops a portable partial discharge detector based on acoustic method,which collects ultrasonic signals generated by partial discharge in high-voltage switchgear using high-frequency acoustic sensor.In order to eliminate the interference of low-frequency noise and high-frequency noise,a band-pass filter is designed,which will be less than 35 kHz.The acoustic signal generated by partial discharge in the frequency range of 38 kHz to 40 kHz can be obtained by filtering the signal above 42 kHz.The acoustic spectrum generated by partial discharge in switchgear can be obtained by discrete fast Fourier transform.The degree of partial discharge in high voltage switchgear can be judged by the spectrum diagram.After practical testing,the detector can realize high voltage switchgear in live operation.The partial discharge of the shutdown and other equipment is inspected by patrol,and it is convenient to use.