The experimental research of vibration characteristics under induction motor windings fault

Vibration exists in the operation of induction motor is a kind of widespread phenomenon. The motor windings fault often causes its vibration change. This paper analysis the causes of motor electromagnetic vibration and establishes the experimental testing system of vibration under motor windings fault. Through the theory analysis and a great deal of experimental tests, the stator and rotor´s radial vibration characteristics were researched when motor occurred fault. Though analyzed the time-domain signal and frequency-domain signal while generating vibration, the relation of failure mode and vibration signal were discussed. Pointed out that the faulty rotor windings will cause the increase of the frequency component of 6f and 32f of the motor vibration signal .As the number of broken bars increase, faulty characteristic amplitude will increase , but the vibration characteristic under no-load is not obvious. Along with the increase of load, faulty characteristic is increasing obviously. Then this vibration characteristic signal can be used to diagnosis rotor windings fault.