Multilevel Switching-Mode Operation of Finite-Set Model Predictive Control for Grid-Connected Packed E-Cell Inverter

摘要

In this article, we propose a modified finite-set model predictive control (M-FS-MPC) for multilevel switching-mode operation of grid-connected nine-level packed E-cell (PEC9) inverter. With a single-dc source, six power switches, back-to-back-connected switches as bidirectional and two capacitors horizontally extended, PEC9 inverter topology has remarkably reduced the components count. Packed E-cell (PEC) prominent feature has the capability of switching among different multilevel voltages: nine-, seven-, or five-level under faulty switch cases without any structural modification and only if the controller is appropriately designed. M-FS-MPC is proposed to operate the grid-connected PEC with the multilevel switching mode under bidirectional switch fault operation. Switching among five-, seven-, or nine-level voltages is attained by proper dc capacitors' voltages regulation, whereas the desired current injection with low total harmonic distortion (THD) and requested power factor for addressing grid connectivity applications is guaranteed. The system discrete model is developed and the experimental results verify the performance and robustness of M-FS-MPC in targeting the capability of PEC multilevel switching-mode operation and grid connectivity requirements in both steady and transient states.