Comparative Analysis of Three- and Five-Level NPC Converters with Predictive Current Control for Reactive Power Compensation

Given the increasing demand for enhanced power quality and higher efficiency in industrial electrical systems and modern grids, this paper presents a comparative analysis of three-level and five-level Neutral Point Clamped (NPC) multilevel converters controlled by Predictive Current Control (PCC) strategies. The study focuses on their operation when connected both to the grid and to a three-phase load, with the primary objective of reactive power compensation and power factor correction. The evaluation encompasses critical performance indicators such as dynamic response, Total Harmonic Distortion (THD), power factor, and both transient and steady-state behavior. Detailed simulations carried out in MATLAB/Simulink provide a quantitative and qualitative assessment of the two converter topologies. Results demonstrate that the five-level NPC topology delivers superior compensation capability, substantially improving the quality of the current injected into the grid. In particular, it achieves a significant reduction in THD and brings the power factor closer to unity when compared to its three-level counterpart. Nevertheless, these advantages are accompanied by increased complexity in terms of circuit design, semiconductor count, and control algorithm implementation. The findings of this work offer a comprehensive technical perspective that can serve as a guideline for selecting the most appropriate topology depending on the trade-off between power quality requirements and implementation challenges. Applications of these results extend to active power filters, Flexible AC Transmission Systems (FACTSs), and smart grids, where reliability, efficiency, and controllability are critical.