Model Predictive Current Control of a Seven-Level Inverter With Reduced Computational Burden

Multilevel topologies gained considerable attention in medium-voltage high-power applications due to their advantages over classic two-level inverters, such as lower loss, higher power quality, and eliminating interface transformers. Moreover, vast research has been done in order to improve the control of the power converters to achieve more efficient and simple controllers. Model predictive control (MPC) is one of the control techniques that has been widely used in power electronics recently due to its advantages, such as fast dynamic response, no need for PI regulators and pulsewidth modulation blocks, and capability of nonlinearity inclusion. On the other hand, the high number of calculations especially for higher level topologies is the disadvantage of this approach. This article presents a new finite control set MPC (FCS-MPC) approach for a seven-level topology. This approach reduces the number of calculations significantly compared to conventional FCS-MPC. Applying the computational efficient FCS-MPC to control the output current and flying capacitors voltages of the seven-level topology reduces the number of calculations from 123 to 36, whereas the execution time is reduced six times. Moreover, simulation and experimental results have been shown to demonstrate the performance and feasibility of the developed control method applied to a seven-level topology.