Experimental Simulation and Electromechanical Characterization of Dynamic Air Gap Eccentricity Faults in PMSG

This paper presents a designed experimental simulation scheme for dynamic air gap eccentricity (DAGE) faults in permanent magnet synchronous generator (PMSG), along with the testing of their electromechanical characteristics. Unlike previous studies, this paper proposes and applies an experimental device setting scheme that enables accurate and convenient calibration of the DAGE fault degree, offering a novel solution for practical DAGE simulation. The experimental unit measures the electromechanical characteristics of the PMSG before and after the DAGE fault, taking into account the influence of load. The mechanical parameter considered is the stator vibration, while the electrical parameter is the circulating current parallel branches (CCPB) inside the stator winding. The characteristic frequencies of stator vibration and CCPB under the DAGE fault are analyzed based on the experimental results and verified through theoretical calculations and finite element analysis (FEA). The findings demonstrate the effectiveness of the proposed DAGE experimental device. Moreover, DAGE failure increases the strength of stator vibration and introduces new frequency components, namely f_r and 2f ± f_r. Under normal operation, the PMSG exhibits no CCPB. However, DAGE faults cause CCPB with frequency components of f ± f_r. Moreover, the severity of the fault degree positively correlates with larger root-mean-square (RMS) values and characteristic frequency amplitudes of stator vibration and CCPB. Furthermore, the amplitude of stator vibration and CCPB decreases with increasing load.