Predictive power control of grid-connected four-level inverters in stationary reference frame

This paper proposes a four-level diode-clamped inverter for the grid connection of high power, medium voltage wind energy conversion systems. A predictive control scheme is presented in stationary reference frame to regulate the active and reactive powers along with the DC-link capacitor voltages. The proposed method doesn´t require any PI controller, phased lock loop and the complex modulation. The discrete-time model of the inverter is used to predict the future behavior of the control variables for all possible switching states generated by the inverter. These predictions are evaluated using a cost function, and then, the switching state which minimizes the cost function is chosen and applied to the inverter. The feasibility of the proposed method is verified by MATLAB/Simulink software.