FCS MPCof Nested Neutral Point Clamped Converter

This paper proposes a model predictive control (MPC) strategy for a nested neutral point clamped (NNPC) converter to control output currents and voltages of flying capacitors. NNPC converter is a four-level converter topology for medium voltage applications with interesting properties such as operating over a wide range of voltages (2.4-7.2KV) without the need for connectingpower semiconductor in series, high quality output voltage, less number of components compared to other classical four-level topologies.

A discrete-time model of the converter is presented, and all the control objectives are formulated in terms of the switching states. During each sampling interval, the predicted variables are assessed by the cost function, and the best switching state which gives minimum value for the cost function is selected and applied to the converter gating terminals. The performance of the NNPC converter and predictive control scheme are verified through MATLAB/Simulink simulations and their feasibility is evaluated experimentally.