超声波局放检测仪校验方法优化

The optimization for calibration of ultrasonic partial discharge detector

文章提出现行超声波局部放电检测仪校验方法中的两个问题:无法真实反映局部放电产生的脉冲超声波工况,无法对超声波在介质中传播而产生的纵波和表面波区别分析。针对第一个问题,文章运用FFT方法分析了波形频带,提出使用上位机控制超声波信号源产生脉冲波和包络正弦波,而不是连续正弦波,并提出相应的灵敏度实验方法;针对第二个问题,文章通过对声波传输路径的分析计算,选择底面直径600 mm、高度300mm的圆柱体钢制试块为实验平台,理论上能够达到区分纵波和表面波的目的。文章最后通过实验对优化方法进行了验证,得到了相关传感器的灵敏度曲线,并以声速为依据进行判断,验证了该方案能有效区分超声波在介质中的类型。

This paper presents two problems of calibration method for ultrasonic partial discharge detector as follows：the method can＇t reflect the working conditions of pulse ultrasonic caused by partial discharge; the method can＇t distinguish between the longitudinal wave and the surface wave when ultrasonic propagates in the medium. For the first problem,this paper analyzes the frequency band through FFT,proposes to control ultrasonic source to give out pulse wave and envelope sine wave rather than continuous sine wave,and puts forward the corresponding sensitivity experiment method. For the second problem,this paper analyzes and calculates the transmission path of ultrasonic,chooses specific cylindroid steel block（ the bottom diameter of 600 mm,height of 300mm） as experiment platform,and distinguishes between the longitudinal wave and surface wave. In the end,experiment shows that the method in this paper can get the sensitivity curve and can effectively distinguish the types of ultrasonic in medium by sound velocity.