I. Introduction
Polyphase induction motors have been the workhorse (main prime movers) for industrial and manufacturing processes as well as some propulsion applications. They are commonly used in ac adjustable speed drives where torque and speed control is indispensable. The ruggedness, ease of control, and cost-effective design of squirrel-cage induction motors are the main appealing features to consumers and engineers for the various aforementioned applications. Due to its popularity, there have been many investigations on condition monitoring and fault diagnostics in electric machines throughout the literature, especially squirrel-cage induction motors [1]–[14]. This is because failure of such motors as prime movers can lead to significant undesirable repercussions such as production downtime, financial loss, adverse environmental effects, and possible personnel injury. Consequently, considerable interest in machine fault diagnostics received from industry and academia has prompted researchers to develop excellent state-of-the-art diagnostic techniques for various possible types of faults such as indicated in Fig. 1. The probability of occurrence of such faults is given in Table I (see [15] and [16]). Therein, both the stator and rotor faults account for around 40% of all faults. Accordingly, the main thrust of this paper centers on electrical stator and rotor faults.
Induction motor fault categories.
Percentage of Failures by Major Motor ComponentsMajor Components | IEEE-IAS [15] % of Failures | EPRI [16] % of Failures |
---|---|---|
Bearing Related | 44 | 41 |
Winding Related | 26 | 36 |
Rotor Related | 8 | 9 |
Other | 22 | 14 |