Predictive torque control of interior permanent magnets synchronous motors in stator co-ordinates

This paper proposes a possible approach to control the synchronous machines with interior (buried) permanent magnets (IPM SM). If properly controlled, this construction allows for an increase in torque through a reluctance component that adds to the main torque caused by the permanent magnets. Since the overall torque depends on the load angle and stator current magnitude, the optimal relationship between these two variables can be pre-calculated prior to the machine start. The inverse procedure allows a determination of the unique load angle and current reference, which, in turn, form a stator flux. The latter is calculated from discretized basic voltage equation in each sampling interval. This procedure is called Predictive Torque Control (PTC). An output variable (reference stator flux) is then passed to the block for Immediate Flux Control (IFC), already tested on induction machines. Its aim is to generate the actual stator flux by selecting proper inverter voltage vectors and determining their application time. The results have been verified on experimental model of a real machine.