瓷质绝缘子超声波探伤检测技术的应用

Application of the Ultrasonic Flaw Detection Technology for Porcelain Insulator

瓷质绝缘子是变电站的关键设备,可以起到绝缘以及支撑导线的作用。由于瓷绝缘子在运行期间长期承受机械负荷,以及风霜雨雪等,设备局部应力逐渐增加,如果瓷质绝缘子内部存在细微缺陷,就可能导致瓷绝缘子及瓷套的损坏,造成重大事故。超声波探伤技术作为一种新型瓷质绝缘子缺陷检测方法可以提前发现瓷质绝缘子的内部缺陷,并能够对运行中的瓷质绝缘子起到很好的监测作用。超声波探伤技术利用超声波具有较强的穿透力并且与异质界面相遇会出现反射、折射或波型转换等特征,将超生波脉冲通过脉冲发生器的探头送至被测设备内,然后接受回波信息,根据回波信息的不同判定设备缺陷并实现缺陷定位。目前油田电网以爬波探伤为主要检测方法,先后完成18座变电所支柱绝缘子检测,开关、刀闸共计800多支,提高了瓷质绝缘子缺陷的检测能力,降低了瓷瓶缺陷对电力安全生产的威胁,确保设备安全运行。

porcelain insulator is the key equipment of substation,with the function of insulation and supporting conducting wires. Because insulator made of porcelain bears mechanical load during operation for a long time and wind, frost, rain and snow, the local stress of the equipment is gradually increasing. If there are small flaws existing in the insulator made of porcelain, it will cause the damage of the insulator made of porcelain and the porcelain case and result in a serious accident. The ultrasonic flaw detection technique is a new flaw detection method for porcelain insulator, which can be used to find the internal defection of the porcelain insulator beforehand,and monitor the porcelain during running. Based on the characteristics of ultrasonic,such as high penetration, reflection, refraction and waveform changing when confronting with heterogeneous interface, etc., ultrasonic pulse is sent in to the equipment to be detected through the pulse generator and echo information is received. The flaw and flaw positioning of equipment is judges according to the different echo information. In oil field power grid,creeping wave is mainly used for flaw detection. The detection of post insulator in 18 substations has been successively completed, with more than 800 switches and knife switches in total, improving the detection ability of porcelain insulator defects, reducing the threat of porcelain insulator defects to power production safety,and the safe operation of equipment is ensured.