Iranian Journal of Electrical and Electronic Engineering

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This paper provides a detailed comparative study concerning the performance of min-projection strategy (MPS) and model predictive control (MPC) systems to control the three-phase grid connected converters. To do so, first, the converter is modeled as a switched linear system. Then, the feasibility of the MPS technique is investigated and its stability criterion is derived as a lower limit on the DC link voltage. Next, the fundamental equations of the MPS to control a VSC are obtained in the stationary reference frame. The mathematical analysis reveals that the MPS is independent of the load, grid, filter and converter parameters. This feature is a great advantage of MPS over the MPC approach. However, the latter is a well-known model-based control technique, has already developed for controlling the VSC in the stationary reference frame. To control the grid connected VSC, both MPS and MPC approaches are simulated in the PSCAD/EMTDC environment. Simulation results illustrate that the MPS is functioning well and is less sensitive to grid and filter inductances as well as the DC link voltage level. However, the MPC approach renders slightly a better performance in the steady state conditions.

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Multiphase electric motors are useful for industrial and military applications that need high power, fault tolerance control, smooth torque, and the ability to share power and torque compared to conventional three-phase electric motors. One type of Multiphase electric machine is Brushless DC Motors (BLDCM) which uses conventional strategies such as hysteresis current controllers. It has important challenges such as high torque ripple, low efficiency, vibrations, and noise that are undesirable for high power applications such as submarines. This paper proposes a new finite control set model predictive control (FCS-MPC) approach with reduction of computational for diode-clamped three-level (DC3L) inverter fed to dual three-phase BLDCM (DTP-BLDCM) by selecting optimal vectors to solve the above problems. Also, an approach of balancing the voltage of the capacitors in two of the DC3L inverters to reduce torque ripple has been proposed. The results of the suggested MPC method are contrasted and verified with the multiband hysteresis current (MHC) method through simulation. The simulation results specify that the suggested MPC controller works superior than the MHC controller. Also, due to the simplicity and low complexity of the suggested MPC strategy used, the real implementation possibility and performance of the controller are checked by simulations for a 4125-V/2.7-MW/350-RPM DTP-BLDCM.