MPC-SVM Method with Subdivision Strategy for Current Ripples Reduction and Neutral-Point Voltage Balance in Three-Level Inverter

This paper proposes a model predictive control-space vector modulation (MPC-SVM) method to achieve current ripple reduction and neutral-point voltage balance in three level inverter. The proposed MPC-SVM method is based on subdivision strategy for improving the performance of the conventional model predictive control (MPC) method. The proposed subdivision strategy consists of two parts: current controller and neutral-point voltage balance controller. In the current controller, various voltage vectors are obtained by subdividing space vector diagram. In the neutral-point voltage balance controller, various offset voltages are obtained by subdividing the offset voltage range. The optimal voltage vector and offset voltage value are independently determined from the cost function of each controller and they are applied to the inverter through the space vector modulation (SVM) method. Since both controllers are based on the finite set model predictive control (FS-MPC) method, the fast dynamic response can be achieved. The simulation and experiment are conducted to validate the effectiveness and performance of the proposed method.