Modified Control Strategy of Stacked Multicell Converter with Model Predictive Control

Owing to its symmetric and extendable circuit characteristics, the stacked multicell converter (SMC) can be configured to provide flexible voltage levels. Traditionally, achieving higher voltage levels of SMC requires extra stacked subcells resulting in extra device costs as well as power losses. To address this, modified capacitor voltage ratios of SMC for the improvement of output voltage resolution are proposed and studied in this paper. The motivation behind is to increase the switching voltage level of SMC meanwhile limiting the numbers of semiconductor devices and flying capacitors (FCs). By applying a model predictive control (MPC) algorithm with reduced computational burden, a SMC constructed with three stacked subcells is investigated under the seven/nine/eleven-level operation modes.