Two Stages FCS-MPC for a Flying Capacitor Converter With Improved Switching Performance

This article proposes a modified finite control set model predictive control (FCS-MPC) strategy for a three-phase three-cell flying capacitor converter implemented in two separate stages. The first one is responsible for controlling the external variables, i.e., the output current, while the second stage is responsible for the internal variables of the converter, i.e., the floating capacitor voltages, the switching losses, and the common mode voltage. The proposed implementation requires a low computational effort and offers great dynamic performance with a significant improvement in the power semiconductors switching characteristics. Experimental results in a 5-kW prototype are provided to sustain our claims.