Virtual-Flux Decoupling Hysteresis Control for the five-level ANPC inverter connected to the grid

Interest in multilevel power converters has been increased in the last decades due to numerous advantages. Therefore, new control concepts have to be developed or existing control techniques must be extended to take advantage of these benefits.However, although multilevel inverters present numerous advantages, some drawbacks are evident. They require a higher number of semiconductors and either multiple isolated dc sources or a bank of series connected capacitors. Consequently, the control complexity increases considerably, since more switching devices normally result in a higher number of possible combinations and the balance of the capacitors has to be guaranteed. In order to fulfill these requirements, this paper extends the Virtual-Flux Decoupling Hysteresis Control (VF-DHC) scheme previously presented for the classical two-level and the industry standard three-level NPC inverters to operate with the recently introduced five-level Active Neutral-Point Clamped Inverter (ANPC).