Abstract: In order to solve the problems of hazards caused by abnormal operation of large-scale rotating equipment such as wind turbines and power systems, we designed an optical fiber vibration real-time monitoring system based on Mach-Zehnder interferometer. Firstly, the interferometer was composed of two 3 dB couplers to increase the sensitivity and stability of the sensor. Secondly, the optical fiber vibration sensor composed of Mach-Zehnder interferometer was used to collect the real-time vibration data of the rotor, and the signal processing unit was used to analyze the collected vibration information. Finally, experiments were tested on a small-scale rotor will rated speed of 2 680 r/min and rated power of 2.8 kW to complete the vibration information of the rotor under normal and fault conditions respectively. The results show that the system has a good monitoring effect on the oprating state of the rotor.

Key words: optical fiber , interferometry technology, Mach-Zehnder interferometer, 3 dB coupler, sensitivity, real-time monitoring