SLUUDM5 March 2026 MSPM0G1507 , MSPM0G1519 , MSPM0G3507 , MSPM0G3519
Field weakening control expands the motor's speed range by reducing the intensity of the motor's excitation magnetic field. Especially after exceeding the rated speed, by injecting a current component opposite to the motor d-axis magnetic field, the total d-axis magnetic field is weakened, allowing the motor to continue accelerating under voltage limitations.
During flux weakening operation, the motor cannot deliver the rated torque. The torque limit Iq is automatically adjusted based on the circular motor current limit defined by ILIMIT = SQRT(Id2 + Iq2).
This feature can be enabled by setting pUserInputRegs->fieldCtrl.b.fluxWeakeningEn to 1b.
Follow the steps below to tune the field weakening control method:
After field weakening control enabled, a separate PI controller applies for Id reference setting. Using pUserInputRegs->systemParams.fluxWeakeningKp and pUserInputRegs->systemParams.fluxWeakeningKi to tune the field weakening control.