Principles of Field Oriented Control (FOC)
Principle of Field Oriented Control
Field Oriented Control (FOC) is based on the concept of applying maximum torque to a rotor. Torque is maximized when force is applied at a 90 degree angle to the object being moved.
For motors with permanent magnet rotors, maximum torque is achieved when the stator field is perpendicular to the rotor.
The stator field is a sum of the fields from the individual windings. An MCU can move the alignment of the stator field by changing the voltages on the individual windings. FOC controllers move the stator field so that it is perpendicular to the rotating rotor field.