Online maximum torque per power losses strategy for indirect rotor flux-oriented control-based induction motor drives

Among the conventional loss minimisation algorithms (LMAs), the model-based approaches have the advantages of fast response and high accuracy. Here, a novel online model-based power losses minimisation approach is presented for indirect field-oriented control (IFOC) of induction motor (IM) drives. The proposed method is introduced as maximum torque per power losses (MTPPL) in which the power losses for a given torque are minimised. The results demonstrate that the proposed approach preserves the LMA merits, while the criterion for the MTPPL scheme is achieved. The mentioned criterion is investigated by a gradient approach so that while the gradient vectors of the torque and power losses are parallel, the MTPPL strategy is realised. The closed-loop IFOC of the MTPPL approach is implemented in real time for a laboratory 2.2kW three-phase IM drive. The experimental results show the capability and validity of the proposed control scheme.