Online Non-Parametric Auto-Tuning of Flux Weakening Controller for IPMSM Drives using Modified Relay Feedback Test

This paper proposes a non-parametric auto-tuning methodology for flux weakening (FW) controller tuning, with specifications on phase margin of the voltage regulation (VR) FW control loop, using the modified relay feedback test (MRFT). Unlike proposed small-signal models in the literature that utilize linearized plant models, the MRFT can be carried out online on the drive system to deduce PI parameters without a prior knowledge of machine parameters. This is particularly important since machine parameters, such as stator resistance and inductances, can deviate when operated at higher temperatures. Furthermore, the VR-FW loop exhibit a varying static gain that must be accounted for when operating the machine in deep FW region. Simulation results demonstrates a superior and robust drive performance in deep FW region when compared to adaptive FW control based on machine parameters.