Predictive control with uniform switching transitions and reduced calculation requirements

A control strategy based on finite-state model predictive control (FS-MPC) for uniform switching transitions distribution and reduced calculation requirements is presented in this paper. FS-MPC evaluates all the available switching states of the controlled topology to find the combination that meets the control objectives. However, the number of switches, along with the computation burden, is significantly increased in multilevel inverters, whereas the switching transitions are not evenly distributed among the switches. By preselecting the evaluated switching states into the cost function of the developed MPC, it is possible to minimize the computational requirements while decreasing the difference in the switching transitions. The performance of the proposed strategy is compared with the classical predictive control and a field-oriented control with space-vector modulation. The methods are applied to an electric drive with a PMSM supplied by a neutral-point-clamped inverter, and the effectiveness of the developed switching-state strategy is validated by examining steady state and transient performances.