Το work with title Development of a diagnostic tool for identifying non-adjacent broken bars in industrial cage motors by Salinas Marios is licensed under Creative Commons Attribution 4.0 International
Bibliographic Citation
Marios Salinas, "Development of a diagnostic tool for identifying non-adjacent broken bars in industrial cage motors", Diploma Work, School of Electrical and Computer Engineering, Technical University of Crete, Chania, Greece, 2024
https://doi.org/10.26233/heallink.tuc.101043
Rotor electrical faults, particularly the progressive degradation of rotor cage bars in induction motors, pose significant threats to both operational efficiency and safety. Early detection is critical to prevent costly downtime and mitigate safety risks. However, traditional diagnostic methods, such as Motor Current Signature Analysis (MCSA) during steady-state operation, often fail to identify non-adjacent broken bars. Although transient analysis during motor start-up can effectively detect such faults, it is impractical in many industrial applications where motors run continuously with infrequent start-ups. To overcome this limitation, this study presents a novel fault detection technique that focuses on identifying non-adjacent broken rotor bars by analysing zero-sequence stray flux during steady-state operation, collected through external flux leakage sensors strategically placed in a symmetrical arrangement.The research is based on extensive simulations of a 1.1 MW induction motor, commonly used in industrial settings, under various load levels and fault scenarios. The study includes healthy motors, as well as motors with faults such as one broken bar, two adjacent broken bars, and two non-adjacent broken bars at half pole pitch. Simulations of the aforementioned cases were conducted using FEM software (Simcenter MAGNET) at a sample rate of 5kHz. The simulated data was then post-processed using MATLAB to accurately diagnose each fault condition and to thoroughly analyse the behaviour of non-adjacent bar breakages.