Improved performance of cascaded multilevel inverter

Abstract

Cascaded H-Bridge (CHB) Multi-Level Inverter (MLI) is widely known for their better performance. This topology is very widely used in renewable applications due to its advantage in the availability of isolated DC links. However, in MLIs the main constraint lies in the usage of switches, so as to avoid the switching losses. But, for the increase of CHBMLI to a next higher level of CHBMLI, the number of switches is mandatorily increased. Hence, remaining the cascaded number to the same value and by the addition of very limited hardware to the existing CHB topology the level of the CHBMLI can be tripled (perspective topology named as "Cascaded Diode Bridge integrated H-Bridge (CDBHB) MLI"). In the amended CHBMLI topology the switching devices are slightly increased. But, still the level of the MLI obtained is doubled for the same number of switching devices. The comparative performance evaluation was performed using extensive simulations in MATLAB Simulink.