Analysis, simulation, and experiments of rotor eccentricity in closed-loop drive-connected induction motors

This paper focuses on the detection of rotor eccentricity faults in induction motors supplied by a vector-controlled drive. With the vector control, the motor and drive operate in a closed-loop fashion. Their behavior is coupled and their fault harmonics interact, which add significant challenges to fault detection above and beyond those faced by conventional line-connected machines. In this paper, the influence of drive controller and mechanical load on the fault detection is investigated, and a reliable detection scheme is proposed. In addition, a new direct time-stepping finite element model is introduced to incorporate the effects of magnetic nonlinearity into simulation. The simulation and experimental results are presented to validate the feasibility of the new detection method.