A new method to optimize q-axis voltage for deep flux weakening control of IPM machines based on single current regulator

The single current regulator algorithm has been proven robust for flux weakening control of surface-mount PM (SPM) machines with active control of d-axis current and a fixed value of q-axis voltage applied. This paper proposes a new method to optimize the q-axis voltage adaptive to variable speeds and torque based on the single current regulator algorithm for the deep flux weakening control of a 50 kW interior permanent magnet (IPM) machine. The advantages of the improved single current regulator algorithm over the conventional one are analyzed and verified by computer simulations. The experimental results show that the proposed method is very robust for the deep flux weakening operation of an IPM motor in a 7:1 speed range.