基于超声波的GIS盆式绝缘子螺栓松动程度监测方法

Monitoring Method on Bolt Looseness Degree of GIS Insulating Spacer Based on Ultrasonic Wave

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运行的可靠性和安全性。文中提出了一种GIS盆式绝缘子法兰螺栓松动程度的超声波监测方法,利用压电传感器进行超声信号的激励与接收,并将压电传感器安装在待测螺栓所连接的法兰两侧,根据超声响应信号的能量衰减率来判断螺栓松动程度。通过实验研究了不同工况下超声响应信号能量及其衰减率的变化规律。结果表明,随着螺栓松动程度的增加,响应信号幅值逐渐下降,信号能量衰减率逐渐增大,单个螺栓松动且松动等级为3时信号能量衰减率可达40.8%;同时发现距离松动螺栓最近的压电传感器接收信号能量衰减率最大。该方法可实现GIS盆式绝缘子法兰螺栓松动程度监测,具有一定的工程应用价值。

The insulating spacer,an important part of GIS,is mainly fixed by flange bolts,but the looseness of bolts will cause such problems as uneven force and even gas leakage of the insulating spacer,which will seriously af-fect reliability and safety of GIS operation.In this paper,a kind of ultrasonic wave monitoring method for the loose-ness of flange bolts of GIS insulating spacer is proposed,the excitation and reception of ultrasonic signal is per-formed by using the piezoelectric sensor,and the piezoelectric sensor is installed on both sides of the flange connect-ed by the bolt to be tested,and the degree of bolt looseness is judged in accordance with the energy attenuation rate of the ultrasonic response signal.The variation of ultrasonic response signal energy and its attenuation rate under different working conditions are studied through experiments.The results show that with increase of bolt looseness,the amplitude of the response signal decreases gradually and the signal energy attenuation rate gradually increases,the annentuation rate of the signal energy,in case of single bolt looseness and the looseness grade is 3,can be up to 40.8%and,at the same time,it is found that the annenuation rate of the receiving signal energy of the piezoelec-tric sensor which is closest to the bolt looseness is maximum.The method proposed in this paper can monitor the looseness of flange bolts of GIS insulating spacer,and has certain engineering application.