Detection of rotor bar breaking fault in induction motors based on Hilbert modulus gyration radius of filtered stator current signal

According to the basic characteristic of rotor bar breaking fault in induction motors and the physical concept of Hilbert transform of sinusoidal signal, this paper gives the definition of Hilbert modulus of filtered stator current signal of induction motors and presents its algorithm by blending Hilbert transform, spectrum analysis/correction and self-adaptive filter techniques perfectly. And then, this paper reveals the rule that the area in complex plane occupied by Hilbert modulus of filtered stator current signal can reflect whether rotor bar breaking fault is present or not, and will increase with the development of this type of fault in induction motors. Thorough analysis based on great simulation and experiment results demonstrates that the revealed rule is correct. Moreover, this paper proposes a novel feature of rotor bar breaking fault, i.e., the Hilbert modulus gyration radius of filtered stator current signal. Simulation and experiment results show clearly that the Hilbert modulus gyration radius of filtered stator current signal, as a feature of rotor bar breaking fault, is sensitive to the fault itself and robust to some extent to the load, and thus can be used to detect rotor bar breaking fault in induction motors.