Closed-loop flux-weakening for permanent magnet synchronous motors

This paper presents a simple robust integrator-like flux-weakening regulator for permanent magnet synchronous machines, based on a general closed-loop flux-weakening which uses a reference stator voltage and DC link voltage feedback. Also, some of the open-loop flux-weakening schemes covering constant torque and power regions are briefly discussed and compared to the proposed scheme. It is seen that the proposed regulator is independent of motor parameters and has superior performance. In addition, a method for tuning of the regulator gain is defined. Following analysis of the regulator dynamics and setup, the results of extensive simulation and experiment are given.