Novel Voltage Trajectory Control for Flux Weakening Operation of Surface Mounted PMSM Drives

This paper proposes a novel voltage trajectory control method for flux weakening operation of surface-mounted permanent synchronous motor drives. The difference between the switching period and summation of active switching times for inverter PWM control is used for flux weakening control, which will be used to modify the d-axis current reference. Since the voltage trajectory of inverter output which is fed to the motor drives, will move along the hexagon of the space vector, the presented method can fully utilize the DC-link voltage and reduce motor current ripple under flux weakening operation condition. The presented method doesn't require any additional hardware and can be realized by software. Experimental results will be shown to confirm the feasibility of the presented method.