New mixed stacked multicell converter with interesting advantages

Multilevel converters are very interesting alternatives for medium and high-power applications. This study presents a new configuration of multicell converters. The main advantages of the proposed converter, in comparison with conventional flying capacitor multicell (FCM) and stacked multicell (SM) converters, are doubling the number of output voltage levels and the root mean square (RMS), improving the output voltage frequency spectrum and lowering the number and rating of components and decreasing the converter losses. Furthermore, the stored energy and rating of flying capacitors will be decreased to half in this topology in comparison with FCM and SM converters. These improvements are achieved by adding only four low-frequency switches to the conventional SM converters configuration. In this topology, the number of high-frequency switches is decreased while the voltage ratings of them during a full cycle are kept constant. Also, a modified phase shifted pulse-width-modulation-based control method has been applied to the proposed topology, which can decrease the harmonic distortions and THD. The circuit is simulated using PSCAD/EMTDC software and simulation results are presented to validate the effectiveness and advantages of the proposed configuration. In addition, the experimental results of proposed configuration prototype have been presented to examine its practicability.