Stator Faults In Induction Motors Research Articles

Diagnosis of Stator Inter-Turn Short Circuits in DTC Induction Motor Drives

This paper addresses the subject of stator fault diagnosis in direct torque control (DTC) induction motor drives. The particularities of the behavior of a DTC drive, when in the presence of inter-turn short circuits, are exploited, thus allowing the proposal of two different approaches for the diagnosis of this type of fault. One of the proposed diagnostic techniques is the well known motor current spectrum analysis. It is demonstrated that in a DTC induction motor drive, with stator inter-turn short circuits, the action of the torque and flux controllers introduce a strong third harmonic in the motor supply currents, which can be used to detect this type of fault. The other diagnostic technique is based on the multiple reference frames theory, recently proposed by the authors for the diagnosis of stator faults in line-connected motors. Here, its use is exploited in the diagnosis of stator faults in DTC induction motor drives. Simulation and experimental results demonstrate the effectiveness of the two proposed techniques for the diagnosis of stator faults but emphasize the fact that the multiple reference frames technique is the preferred one when the residual asymmetries of the motor are not negligible.

ASYMMETRICAL STATOR AND ROTOR FAULTY DETECTION USING VIBRATION, PHASE CURRENT AND TRANSIENT SPEED ANALYSIS

Condition monitoring of electrical machines has received considerable attention in recent years. Many monitoring techniques have been proposed for electrical machine fault detection and localisation. These techniques include the measurement of stator voltage and current, air-gap and external magnetic flux density, output torque, internal and external temperature, and case vibration. However, no comparison between these technologies in term of sensitivity to faults has been given yet. This paper shows that experimental analyses of asymmetrical stator and rotor faults in three-phase induction motors by using vibration, phase current and transient rotor speed analysis. The performance and sensitivity of the above three techniques are given.