The invention provides a non-intrusive diagnosis method for typical rotor faults of a synchronous phase modifier, and the method comprises the steps: carrying out finite
element modeling and fault working condition setting, carrying out
simulation to obtain
magnetic field distribution data under each working condition, carrying out the extraction and feature analysis of stray
magnetic field signals, extracting
time domain and
frequency domain signals of a stray
magnetic field under healthy and various fault working conditions, and carrying out the diagnosis of the typical rotor faults of the synchronous phase modifier. Fundamental wave, odd-even
harmonic components and
signal change trends are compared and analyzed, stray magnetic field characteristics corresponding to faults are extracted and recognized, diagnosis criterion establishment and
fault recognition are carried out, diagnosis criteria and threshold values of rotor turn-to-turn
short circuit, dynamic eccentricity and shaft-
diameter composite eccentricity faults are established according to the stray magnetic field characteristics, and the fault diagnosis accuracy is improved. And when the specific
harmonic amplitude or change characteristic of the stray magnetic field
signal exceeds the criterion threshold, determining the rotor fault of the corresponding type and degree. Equipment dismounting or structure reconstruction is not needed, the detection
system is simple in structure, internal fault characteristics of the phase modifier can be reflected in real time, and high sensitivity and practicability are achieved.