Model Predictive Torque Control with low Torque Ripple for Interior PM Motor Variable Speed Drives

Abstract

This paper proposes a discrete Model Predictive Torque Control (MPTC) methodology, utilizing low torque ripple for Interior Permanent Magnet Motor (IPMM). The proposed controller utilizes a non-linear accurate discrete IPMM model, as well as a convenient cost function, in order to achieve optimal tracking control over wide speed range. More specifically, Maximum Torque per Ampere (MTPA) and Field Weakening (FW) operating principles are imposed via particular terms in the cost function. Typically, the switching principle of MPC in voltage-source inverter causes significant torque ripple. The designed MPTC forces the produced electromagnetic torque to remain within certain tolerance bands, through a specific constraint. The developed IPMM control technique is evaluated and compared with relevant MPTC approach without torque ripple limitation, under both steady state and dynamic operating conditions. The obtained results verify the superiority of MPTC in terms of robustness and dynamic behavior, as well as its effectiveness in reducing the IPMM torque ripple.