Predictive current control method for dual three‐phase PMSM drives with reduced switching frequency and low‐computation burden

Abstract

The multiphase motor drives have attracted more and more attention during the last decade since they offer advantages of high-power rating, lower voltage and current stresses in semiconductor switches, and high-fault-tolerant ability, compared to the conventional three-phase drives. This study presents a novel two-step model predictive control (MPC) method for currents in two-level voltage-source inverters fed dual three-phase permanent magnet synchronous motor drives, aiming at reducing the switching frequency and computation burden of the system. In the first step, the proposed method searches the phase having the maximum phase current error among six phases, and then changes the switching signal of that phase depending on the requirement of current change. Thus, overlarge error in the hysteresis-based predictive control is avoided. In the second step, switching signals are changed in two phases at most and only six voltage vector candidates are evaluated with MPC within one sampling period. So, the switching frequency is reduced and the computation burden is released compared to the conventional finite-control-set -MPC method. Finally, the experimental results are given to verify the validation of the proposed scheme and compare the performance to the other classical MPC methods.