Demagnetization fault diagnosis in permanent magnet synchronous motors: A review of the state-of-the-art

•A review of state of the art on demagnetization fault diagnosis was studied deeply.•Critical points in fault diagnosis are discussed aiming to safety and cost management.•Critical comparison on all existent demagnetization diagnosis methods was done.•It is proved that DE and UL have the same signature frequencies as partial demagnetization.•MCSA have some limitations in frequency component under uniform demagnetization.

There are a lot of research activities on developing techniques to detect permanent magnet (PM) demagnetization faults (DF). These faults decrease the performance, the reliability and the efficiency of permanent magnet synchronous motor (PMSM) drive systems. In this work, we draw a broad perspective on the status of these studies. The advantages, disadvantages of each method, a deeper view investigated and a comprehensive list of references are reported.