Permanent Magnet Motor

Synchro-Smart Permanent Magnet Motor

The submersible permanent magnet synchronous motor directly drives the pump system without requiring a gear reducer due to the inherent low speed, large torque output of permanent magnet motors.  The benefits to PCP’s driven with downhole PMM’s are the compact slim motor size, higher electrical efficiency,  and higher power factor performance.

The superior efficiency of permanent magnet motors over conventional induction motors come from the rotor comprised of permanent magnet material and not requiring an electrically induced magnet field.   The energy savings in a permanent magnet rotor comes from the elimination of induced voltage and current to magnetize the rotor and the elimination of rotor copper losses  from the Joule effect.  While induction motors must have slip to induce voltage on the rotor, the permanent magnet motor does not have slip loss and operates as a synchronous motor, with the rotor rotating at the identical speed of the rotating magnetic field of the stator.   Because of the synchronous operation of the PMM, there is much higher power factor operation reducing the apparent power required.  Permanent magnet motors eliminate rotor circuitry and are more compact making them well suited for down-hole operation.  Additionally the smaller design allows the pole count of the rotor to be increased enabling lower rotational speeds, thus eliminating the gear reducer required with a two-pole induction motor.  The higher efficiency and lower power loss of the PMM reduces the operating temperature

The Synchro-Smart™ PMM has been designed for reliable start-up and long term operations. The higher efficiency and lower power loss of the PMM reduces the operating temperature and increasing the expected operation life.  The permanent magnet rotor operation is maintained with an anti-magnetization algorithm to avoid magnet degradation.  The motor health is also monitored by the Synchro-Smart™ Control and Communications Cabinet to alert any abnormal motor behavior.