Maximum-Torque-Per-Watt Control Framework for Variable Flux Reluctance Machines with Magnetic Saturation and Cross-Coupling

This paper suggests a maximum-torque-per-watt (MTPW) control approach for a variable flux reluctance machine (VFRM), considering factors like the machine's magnetic saturation and cross-coupling between field and armature windings, which are both located in the stator of the VFRM. The VFRM's torque production, which can be highly affected by saturation, relies on the cross-coupling between field and armature windings, and on the varying field and armature currents. The operating points on the torque-speed locus are determined by different combinations of these currents. The paper presents a strategy to obtain the optimum combination of reference field and armature currents based on a saturation-dependent model with a focus on minimizing the total copper loss. The proposed method is to be validated on a VFRM drive simulation, and experimentally.