Direct control of the stator flux linkage applying in the permanent magnet synchronous motor

A new velocity and torque control strategy based on the direct control of stator flux linkage is introduced due to the disadvantage of permanent magnet synchronous motor circuit vector control and traditional direct torque control. By controlling the trajectory of stator flux linkage vector, flux linkage and torque control are achieved, thus permanent switching frequency and small flux linkage pulse are obtained. The necessary condition of the direct flux linkage control is also given in this paper. The experimental result indicates that the strategy developed which is applicable to the weak sector control in the permanent torque area, is better than the traditional circuit control strategy. Further more, it improved the dynamic response of velocity and torque control in a wide velocity range.