Permanent Magnet Synchronous Motor (PMSM)

  • Constructions and types- (IPM) internal permanent magnet
  • Working principle - the rotation of the field gets synchronised with the rotor, consequently there is zero slip in the field. The RPM is constant, depending upon the input command
  • Permanent magnet synchronous motor control



A permanent magnet synchronous motor (PMSM) - is a synchronous electric motor whose inductor consists of permanent magnets.

The main difference between a permanent magnet synchronous motor (PMSM) and an induction motor is in the rotor. Studies1 show that the PMSM has an efficiency of approximately 10% more than a highly efficient (IE1) induction electric motor, provided that the stator has the same design, and the same variable frequency drive is used for control. Now, In this case, permanent magnet synchronous electric motors while in comparison with other electric motors have the best performance: power/volume, torque/inertia, etc.

Permanent magnet synchronous motor constructions and types -

A permanent magnet synchronous motor, like any rotating electric motor, consists of a rotor and a stator. The stator is the fixed part. The rotor is the rotating part.



Typically, the rotor is located inside the stator of the electric motor, there are also structures with an external rotor - inside out electric motors.

Constructions of a permanent magnet synchronous motor: on the left - standard, on the right - inside out.

The rotor consists of permanent magnets. Materials with high coercive force are used as permanent magnets.
According to the rotor design, synchronous motors are divided into:
• electric motors with salient pole rotor;
• electric motors with non-salient pole rotor.