Nine-Level Active Neutral Point Clamped Converter with Cascading H-Bridges Fed by Flying Capacitors

A novel active neutral point clamped bidirectional multilevel inverter is proposed, consisting of flying capacitors with H-bridge interconnection circuit that allows for commutating any combination of flying capacitors and their polarity in the current path. The flying capacitor voltages are scaled by 1/2
ⁿ
factor to maximize the number of output voltage levels. Each intermediate output voltage pole has multiple possible combinations, where each flying capacitor can be charged or discharged, thus ensuring the simple capacitor voltage balancing capability within the same voltage pole. The simulation analysis demonstrated good performance and feasibility of the proposed topology for high power converters.