基于超声波的GIS盆式绝缘子法兰螺栓松动监测方法

Monitoring Method of Flange Bolt Looseness of GIS Insulating Spacer Based on Ultrasonic Method

盆式绝缘子是GIS中的重要组成部分,盆式绝缘子主要通过法兰螺栓进行固定,但螺栓松动会导致盆式绝缘子受力不均甚至气体泄漏等问题,严重影响GIS运行可靠性。文中提出了一种GIS盆式绝缘子法兰螺栓松动的超声波监测方法,通过控制压电片进行超声信号的激励与接收,根据压电片接收信号的均方根偏差来反映螺栓松动状态,研究了不同工况下超声接收信号幅值及其均方根偏差的变化规律,并进行了有限元分析及实验验证。结果表明,随着松动螺栓数量的增加,压电片接收信号的幅值逐渐下降,信号均方根偏差逐渐增加;同时距离松动螺栓最近的压电片信号均方根偏差值最大。文中提出的方法可判断GIS盆式绝缘子法兰螺栓松动的数量及位置,实现法兰螺栓松动监测。

Insulating spacer is an important part of GIS,and is mainly fixed by flange bolts.Horever,looseness of bolts can cause such problems as uneven stress and even gas leakage,which seriously affect the operation reliability of GIS.In this paper,a kind of ultrasonic monitoring method for the flange bolt looseness of GIS insulating spacer is proposed.The ultrasonic signal is excited and received by controlling the piezoelectric sheet,and the bolt looseness state is reflected according to the root mean square deviation of the piezoelectric sheet receiving signal.In this paper,the variation of ultrasonic receiving signal amplitude and root mean square deviation under different working conditions is studied,and finite element analysis and experimental verification are carried out.The results show that with the increase of the number of loose bolts,the amplitude of the received signal of the piezoelectric sheet gradually decreases,and the signal root mean square deviation gradually increases.At the same time,the signal root mean square deviation value of the piezoelectric sheet closest to the loose bolt is the largest.The method proposed in this paper can determine the number and position of flange bolts of GIS insulating spacer and realize the monitoring of flange bolts.