Το έργο με τίτλο False negative diagnosis of demagnetization in direct drive permanent magnet generators από τον/τους δημιουργό/ούς Gyftakis Konstantinos, Rasid Syidy Ab, Mueller Markus διατίθεται με την άδεια Creative Commons Αναφορά Δημιουργού 4.0 Διεθνές
Βιβλιογραφική Αναφορά
K. N. Gyftakis, S. Rasid and M. Mueller, "False negative diagnosis of demagnetization in direct drive permanent magnet generators," in Proceedings of the 2022 International Conference on Electrical Machines (ICEM 2022), Valencia, Spain, 2022, pp. 696-702, doi: 10.1109/ICEM51905.2022.9910919.
https://doi.org/10.1109/ICEM51905.2022.9910919
Demagnetization is a fault occurring in permanent magnet machines, leading to increased vibrations, noise and reduction of efficiency in the short term. However, if not detected early, demagnetization will deteriorate the machine via higher current and temperature increase that will enhance the severity level and lead to a catastrophic failure. Such conditions are extremely costly when they concern direct drive applications, typical in offshore energy harvesting. Prompt diagnosis is required. The stator current analysis has been one of the favorable diagnostic methods due to its non-intrusiveness, low cost and online capabilities. Despite that, this paper proves that the monitoring of the stator current is not always reliable because it directly depends on the geometrical and manufacturing characteristics of the permanent magnet generator. Multiple cases that may lead to false negative diagnostic alarms are revealed in this work for the first time, prompting further research towards alternative diagnostic methods.