Voltage control of interior permanent magnet synchronous motor drives to extend DC-link voltage utilization for flux weakening operation

This paper proposes a new voltage control technique for IPMSM drives to extend DC-link voltage utilization for flux weakening operation. The presented method does not require look-up-table and motor parameter for flux weakening operation. The difference between the switching period and summation of active switching times for PWM control of inverter is used to modify the d-axis current reference under flux weakening region such that the voltage trajectory of inverter output can move to the hexagon of the space vector to extend the utilization of DC-link voltage. As the summation of active switching times is less than its switching period, constant torque with maximum torque per ampere (MPTA) control is retained. In contrast, flux weakening control is considered. Smooth and automatic transition between constant torque and flux weakening regions can be achieved. Experimental and simulation results will be presented to fully support the claims.