An Adaptive Maximum Torque Per Amp Control Strategy

Maximum torque per amp (MTPA) control of induction motor drives seeks to achieve a desired torque with the minimal possible stator current, which is favorable in terms of inverter operation, and nearly optimal in terms of machine efficiency. This work demonstrates that existing MTPA controls perform sub-optimally as temperature varies. An adaptive MTPA control strategy is proposed that always achieves optimal performance regardless of rotor temperature and does so without exhibiting the hunting phenomenon. The proposed control is experimentally shown to (i) accurately achieve the desired torque, and (ii) always satisfy the maximum torque per amp condition