A Simplified Model Predictive Control Algorithm Based on mn Coordinate System for T2C-HB Converter

Due to the extensive computational burden of enumeration algorithm employed in finite control set model predictive control (FCS-MPC) for multilevel converters, this article proposes a simplified MPC (SMPC) based on mn coordinate system. First, the space vector diagram is normalized for simple and better current tracking, then, it is further divided into zones corresponding to vectors. The reference voltage vector location is determined according to boundary conditions. Finally, an arbitrary number of adjacent vectors with sequential order are selected according to the location of the reference vector. The SMPC scheme is independent of the voltage levels of the converter in terms of current tracking, requiring no prestored lookup tables or iterative operations with constant computation cost. An analysis of the computational complexity of the SMPC scheme is presented, and comparisons with other methods are discussed. By incorporating a voltage control cost function, it selects optimal switch states to balance neutral point (NP) voltage and floating capacitor voltages. The effectiveness of the SMPC scheme is verified in simulation and experimental results.