Independent Cost Function Model Predictive Current Control for SMPMSM Drive

To achieve controllable <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i>-axis and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i>-axis current performance with inverter switching frequency reduction, an independent cost function model predictive current control (ICF-MPC) is proposed for surface mounted permanent magnet synchronous motor (SMPMSM) drives. First, two independent cost functions are designed for <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i>-axis and <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i>-axis individual current error. Then, a rectangular constraint that satisfies <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dq</i>-axes current performance is presented to obtain the voltage vector space. Subsequently, a direct selection and calculation method is proposed to obtain the reference voltage vector, based on the principle of balancing current ripple and switching frequency. The proposed ICF-MPC achieves simultaneous optimization of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">d</i>-axis current performance, <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">q</i>-axis current performance, and switching frequency without weighting factors. The controllable current performance and switching frequency reduction are demonstrated by the experimental results.