Simplified model-free predictive current control for interior permanent magnet synchronous motors

Abstract

A simplified model-free predictive current control (SMFPCC) for an interior permanent magnet synchronous motor (IPMSM) drive system is presented. The SMFPCC requires neither pulse width modulation nor a regulator. Unlike existing model-based predictive current controllers (MBPCCs), the proposed method is based on stator current detection, meaning that system parameters such as stator resistance, stator inductance, and back-EMF are not needed. In each sampling period, the stator current is detected only once, rather than twice, thus simplifying the process. Furthermore, to reduce both the switching losses of the inverter and the time consumed, one of four (rather than eight) candidate switching states is selected via the minimisation of a cost function. To compare their performance, both the SMFPCC and the MBPCC are realised on an IPMSM drive system and implemented through a digital signal processor.