Cascaded Topologies With H-Bridge Floating DC-links Using FCS-MPC Operating as Rectifiers

This paper presents the use of Finite Control Set - Model Predictive Control (FCS-MPC) applied to two topologies of multilevel converters with H-bridges connected in series to a three-phase converter operating as rectifiers. One of the topologies has a reduced number of controlled switches. Both configurations are analyzed for two different dc-link ratios between the H-bridge and the three-phase converter. Also, to avoid the use of transformers, which can make the system heavier and bulkier, floating capacitors were used in the topologies. Furthermore, a reduced computational burden (RCB) method is proposed, removing existing redundancies in the switching vectors. All studied cases will be analyzed based on their current total harmonic distortions (THD), average switching frequency $(f_{s})$ and dynamic response.