A Model Predictive Torque Control With Power Factor Improvement Without Weighting Factor Adjustment

In motor control system, when inverter capacity is fixed, the increase of power factor is conducive to improving the motor overload capacity, thus improving the operation stability. A model predictive torque control (MPTC) of permanent magnet synchronous motor (PMSM) with power factor improvement and no weighting factor adjustment is proposed. Because error between the predictive and reference values of torque and flux linkage can be determined by the complex power error, the complex power error of same dimension can be used to replace the flux linkage error and torque error in the cost function of traditional MPTC. Therefore, the complicated adjustment process of weighting factor between torque and flux linkage is avoided. The introduction of power regulation coefficient <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> is aimed at improving the power factor of the motor system. When there is no need for a higher power factor, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> = 1. When there is a need for higher power factor, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i> ≠ 1. By giving the easy selection principle and reasonable value of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</i>, the reactive power occupancy can be appropriately reduced under good steady-state performance to improve the power factor of the motor. Simulation and experiments demonstrate the effectiveness of the method proposed in this paper.