Power tower bolt looseness detection method based on phase-sensitive optical time domain reflection technology

Abstract Due to the vibration threat during the operation of equipment, the bolt structure of the power tower will be loose, which seriously threatens the safety of power operation and maintenance. An innovative method utilizing the principle of phase-sensitive optical time domain reflection has been designed to effectively detect the loosening of bolts on power towers in response to the aforementioned issues. Phase-sensitive optical time-domain reflection technology is introduced to capture subtle vibration signals caused by bolt loosening. The detection principle is constructed to adjust the components of the static magnetic field in different directions so that the electromagnetic ultrasonic transducer can receive transverse guided waves and longitudinal guided waves. An in-depth analysis was conducted on the operational mechanism of phase-sensitive optical time-domain reflection technology. According to this principle, the ultrasonic wave emitted by an electromagnetic ultrasonic transducer propagates along a certain path, and the guided wave velocity is calculated. Thus, the realization process of bolt looseness detection in a power tower is constructed. The experimental results show that the loosening rate of bolts is effectively reduced after the application of this method, which greatly promotes overall safety. The root mean square error of this method is smaller, and the detection effect is the best.