Cascaded Multilevel Inverter with Developed H Bridge Units

Nowadays, the multilevel inverters have received much attention because of their considerable advantages such as high power quality, lower harmonic components, lower dv/dt and lower switching Losses. There are three main types of multilevel inverters, Diode clamp multilevel inverter, flying capacitor multilevel Inverter, and cascaded multilevel inverter. The Cascaded multilevel inverters have received special attention due to the modularity and simplicity of control. Here, a new single- phase cascaded multilevel inverter based on novel H-bridge units is introduced. In order to generate all voltage levels (even and odd) at the output, different algorithms can be to determine the magnitudes of dc voltage sources. Then, the new algorithms are compared to investigate their advantages and disadvantages. This topology is able to increase the number of output voltage levels by using a lower number of power electronic devices such as switches, power diodes, driver circuits, and dc voltage sources that lead to reduction in installation space and cost of the inverter. In addition, in the new cascaded multilevel inverter, not only the number of required power electronic devices is reduced, but also the amount of the blocked voltage by switches, and the number of different voltage amplitudes of the used sources is decreased. These features are some of the most important advantage of the new topology. Simulation is done in MATLAB 2009a environment and the waveforms are obtained. For the experimental setup the dc sources selected are 2V, 4V, 14V, 28V.