Large generator rotor distortion sensing monitoring technology research

In view of the shortage of direct measurement method for shafting of large generator sets, this paper proposes a sensor monitoring technology based on illumination emphasis. The article first introduces the research status of the shaft torque of thermal power units, and expounds the theory of mode interference and the theory of twist sensing. Then, the LP mode simulation of single-mode fiber and two-mode fiber is carried out, which is an effective method for symmetrical higher-order mode. Finally, the simulation of the mode interferometer, the spectrum and the phase during twisting is carried out. It is clarified that the non-circular symmetrical mode with π phase difference electric field distribution is the key inducement of the interferometric phase jump and spectrum flipping in twisting measurement. This article provides theoretical guidance for subsequent device fabrication and spectral distortion analysis.