The large-signal SFG model for cascaded multilevel inverters with experimental verification

In this paper, the switching flow-graph (SFG) modeling technique is used to build the large-signal model of a cascaded multilevel inverter. With the concept of virtual switch and virtual switching function proposed in SFG modeling technique, the large-signal SFG model of a cascaded multilevel inverter can be derived easily and without complex mathematic works. The SFG model can also be implemented in MATLAB/SIMULINK directly and only 1/9 CPU time is needed as compared with PSPICE model. Based on the developed SFG model, the behavior of cascaded multilevel inverters can easily be analyzed. The experimental examples demonstrate that the simulation results by using SFG model are closely agreed with the experimental results.