A hybrid detection method of broken rotor bars in cage induction motors

This paper emphasizes to develop a hybrid detection scheme for induction motor broken rotor bar fault, taking into account the intrinsic asymmetry, air-gap eccentricity and rotor misalignment of induction motors. Firstly, numerical simulation and related experiments of broken rotor bar fault have been performed successfully. Secondly, a series of principles and methods, which assure the sensitivity and reliability of broken rotor bar fault detection in practice, are generalized and revealed, based on thorough analysis of simulation and experimental results. Finally, a hybrid scheme to detect broken rotor bar fault, which blends continuous subdivision Fourier transform, self-adaptive filter, rotor slot harmonics based slip estimation and detection threshold self-tuning technique perfectly, is proposed in this paper. Fault detection instances in laboratory demonstrate that the presented scheme is valid and effective.