Single-phase Cascaded H-bridge Neutral-Point Clamped Inverter: A comparison between MPC and PI control

In this paper, the control of a single-phase cascaded H-bridge neutral-point clamped inverter is investigated. The grid-tied inverter is employed to interface Photovoltaic (PV) panels to the utility grid. A MPC and a classical controller are presented and their effectiveness is illustrated by being compared in terms of several quantitative and qualitative performance indices. The computation burden of the microprocessor, dynamic response and THD compliance with the international standards are some of the considered quantitative characteristics. On the other hand, ease of control development, adaptability to different operating conditions, neutral-point potential balancing along with independent control of each inverter cell are some of the qualitative indices to be investigated. The performances of both controllers are validated by extracting power from two PV strings.