Performance of variable frequency ISPWM technique for a cascaded multilevel inverter

Cascaded multilevel inverter is very effective for high power applications. The cascaded multilevel inverter is mostly used compared to other multilevel inverters (MLI). Mainly this paper focuses on cascaded multi level inverter using two unequal dc sources in order to produce a seven level output voltage by using the variable frequency inverted sine pulse width modulation technique (ISPWM). This method reduces the no of dc sources and switching elements. This technique combines the advantages of inverter sine wave variable frequency carriers for a seven level inverter. The performance evaluation of the ISPWM technique for cascaded multilevel inverter is carried out through MATLAB/SIMULINK and the absence of lower order harmonic (THD) is ensured with less switching losses.