Fault-tolerant PM machines: A review

Synchronous Permanent Magnet (PM) machines have been gaining a lot of interest over the years. This is due to their several advantages including high power density, high efficiency, and high reliability. One of the key concerns about PM machines especially in safety-critical applications has been the issue of fault-tolerance since the machine cannot be de-excited. A lot of work has been done both on the machine side as well as the power converter side (including power converter configuration and remedial control strategies). This paper will provide a thorough review and summary of what has been covered in literature up-to-date. The paper will highlight the tradeoffs involved in the various proposed methods and strategies with more emphasis on the machine side.