What are the advantages of PM motors?

The advantages of permanent magnet motors are:

1. Since high-energy PMs are used, the overall weight and volume can be reduced for a given output power, leading to higher power density.
2. Since rotor copper losses are absent, they offer higher efficiency.
3. Machine heat can be dissipated to the surroundings easily as the heat mainly arises in the stator.
4. PM excitation has no risk of manufacturing defects, overheating, or mechanical damage, they inherently offer higher reliability.
5. Since, rotor does not have copper winding, it posses lower electromechnical time constant and hence better dynamic response.