2 Field Oriented Control

The Field Oriented Control (FOC) takes phase currents and the rotor magnetic field vector angle of the three-phase AC motor as inputs and generates a commutation pattern for a three-phase voltage source inverter. The resulting stator flux is at a specified angle to the rotor magnetic field vector, thereby providing optimal torque and speed performance.

The following section discusses the basic FOC scheme to control PMSM VFD.