Logic-Equations-Based Modulation Technique for Natural Balance Control of an Improved Active-Neutral-Point-Clamped (I-ANPC) Multilevel Converter

Multilevel voltage-source power-converter topologies are used primarily for medium/high-voltage applications including adjustable-speed drives, FACTS devices, HVDC transmission, etc. Active neutral-point-clamped (ANPC) voltage-source converter as a derived topology from NPC family is a well-established configuration for medium-voltage market. This paper explores the Improved-ANPC (I-ANPC) converter and analyzes its major advantage compared with the classical flying-capacitor multilevel topologies. Further, a set of logic-equations are derived for natural balance control of the seventeen-level and twenty-one-level I-ANPC converters. The simulation results are presented to validate the logic-equations-based modulation method for control of the latter I-ANPC multilevel converters.