Model Predictive Control of a Three-Level NPC Rectifier with a Sliding Manifold Term

In this paper, a finite control set model predictive control (FCS-MPC) method for three-level neutral-point-clamped (3L-NPC) rectifiers without the outer control loop is presented. The proposed control method is very simple as only a sliding manifold term is added into the cost function to regulate the dc-bus voltage directly. Instead of calculating the suitable dynamic references, only the steady-state references are required in this method. Besides, we have compared the conventional proportional-integration controller based MPC method (PI-MPC), MPC with dynamic references design method (DR-MPC), and the proposed MPC with a sliding manifold term method (SM-MPC) with simulation. The simulation results show that the proposed SM-MPC outperforms the PI-MPC in the condition of the step change in load and has advantage over the DR-MPC when the voltage reference changes.