超声频谱分析技术在1100kV盆式绝缘子金属夹杂物检测中的应用研究

Application Study of Ultrasonic Spectrum Analysis Technique in Detecting Metallic Inclusion of 1100kV Basin-type Insulator

采用超声频谱分析技术对厚度为52 mm的环氧浇注绝缘材料底面下直径为0.8～0.25 mm的铝合金夹杂物进行了定量检测。提取不同损伤状态下底面回波功率谱相对于基准信号的均方差(RMSD)值计算结果作为定量表征指数。结果表明:存在铝合金夹杂时,RMSD的数值随损伤尺寸的减小而减小。借助超声频谱分析技术可以对直径为0.25 mm的铝合金夹杂物进行有效检测。

The aluminum inclusions with diameter of 0.8~0.25 mm bonded at the bottom of the epoxy casting insulating material with thickness of 52 mm were tested quantitatively by ultrasonic spectrum anal-ysis technique. The root mean square deviation（RMSD） of the power spectrum of the reflected wave un-der different damage states compared to reference signal was extracted as damage index. The results show that when the aluminum inclusions exist, the RMSD decreases with the decrease of the aluminum inclusion diameter. The ultrasonic spectrum technique can effectively test the aluminum inclusion with the diameter of 0.25 mm.