Cage-rotor induction motor inter-turn short circuit fault detection with and without saturation effect by MEC model

• Published in: ISA transactions 2016-09, Vol.64, p.216-230
• Main Author: Naderi, Peyman
• Format: Article
• Language: English
• Subjects: Eccentricity; Fault detection; Faults; Harmonics; Inter-turn short circuit fault; Local saturation effect; Magnetic-Equivalent-Circuit (MEC); Saturation; Short circuits; Strategy; Transaction processing
• ISSN: 0019-0578; 1879-2022
• DOI: 10.1016/j.isatra.2016.05.014

The inter-turn short fault for the Cage-Rotor-Induction-Machine (CRIM) is studied in this paper and its local saturation is taken into account. However, in order to observe the exact behavior of machine, the Magnetic-Equivalent-Circuit (MEC) and nonlinear B–H curve are proposed to provide an insight into the machine model and saturation effect respectively. The electrical machines are generally operated near to their saturation zone due to some design necessities. Hence, when the machine is exposed to a fault such as short circuit or eccentricities, it is operated within its saturation zone and thus, time and space harmonics are integrated and as a result, current and torque harmonics are generated which the phenomenon cannot be explored when saturation is dismissed. Nonetheless, inter-turn short circuit may lead to local saturation and this occurrence is studied in this paper using MEC model. In order to achieve the mentioned objectives, two and also four-pole machines are modeled as two samples and the machines performances are analyzed in healthy and faulty cases with and without saturation effect. A novel strategy is proposed to precisely detect inter-turn short circuit fault according to the stator׳s lines current signatures and the accuracy of the proposed method is verified by experimental results. •Purpose- Obtaining of an integrated method for inter-turn short circuit fault detection for the Cage-Rotor Induction Machine (CRIM) with and without considering of saturation effect.•The Magnetic-Equivalent-Circuit (MEC) is proposed for machine modeling and nonlinear B–H curve is considered for saturation effect.•The machine has some differential equations which are converted to algebraic type by trapezoidal method. On the other hand, some nonlinear equations are present due to saturation effect. A set of nonlinear algebraic equation should be solved by numerical method. Therefore, the Newton–Raphson technique is used for equation solving during of the considered time step.•Generally, the operating point of electrical machines is close to the saturation zone due to designing considerations. Moreover, some current and torque harmonics will be produced due to time and space harmonics combination, which cannot be studied when saturation modeling is neglected. Considering both space and time harmonics, a method is proposed for inter-turn short circuit fault detection based on the stator current signatures and the machine performance is analyzed in healthy an