Explain the operating principle and advantages of synchronous reluctance motors.

Synchronous reluctance motors (SynRM) use rotor saliency to produce torque - the rotor has high reluctance paths (barriers) and low reluctance paths (iron) but no magnets or windings. Torque arises from rotor's tendency to align its low-reluctance d-axis with stator MMF. Advantages include: no rotor losses, no rare-earth magnets, robust construction, and high efficiency (IE4-IE5 possible). Requires VFD for operation. Adding PMs to barriers creates PM-assisted SynRM with even higher torque density. Growing adoption in industrial drives.