Rotor Eccentric Diagnosis of High-Voltage Motor in Nuclear CRF Pump Using Vibration Signals

This paper investigates the effect of rotor eccentric induced unbalance magnetic pull (UMP) on the vibration performance of the high-voltage motor that drives the Nuclear CRF Pump. Firstly, the UMP calculation model was established by expanding the air gap permeability into the form of Fourier series. Then, the integration of Maxwell stress both on the stator and the rotor surfaces helps us to obtain the nonlinear analytical expression of the UMP. After deriving the nonlinear oil film force of the slide bearing, the MDOFs vibration model of the eccentric rotor-slide bearing system in the high-voltage motor was established and numerically solved. Through the comparisons of simulated and experimental results, conclusions can be drawn that our model is capable of characterizing feature frequencies of rotor eccentric fault and can be applied to detect the fault of the high-voltage motor in CRF pump-set.