A method for rotor vibration monitoring of induction motor by air-gap flux detection

This paper presents results of the finite-element (FE) analysis and experiment of air-gap flux variation in induction motor when rotor eccentricity phenomenon occurs. An accurate modeling and analysis of rotor vibration in the motor are made using air-gap flux simulation, and search coils are used for measuring the actual magnetic flux. The simulated vibration system with 4-poles, 380 [V], 7.5 [kW], 1,768 [rpm] induction motor is built, and search coils are designed and inserted under the stator wedge of the motor. The FE analysis results are compared with experiment test results, and it shows that it is an effective method for developing on-line monitoring system on rotor vibration of an induction motor.