A Hybrid Cascaded Seven-Level Inverter With Novel Pulse Width Modulation Technique For Pv Applications

摘要

The most popular cascaded H-bridge apart from other multilevel inverters is the capability of utilizing different dc voltages on the individual H-bridge cells which results in splitting the power conversion amongst higher-voltage lower-frequency and lower-voltage higher-frequency inverters. This paper proposes a single-phase seven-level inverter for grid-connected photovoltaic systems, with a novel pulse width-modulated (PWM) control scheme. Three reference signals that are identical to each other with an offset that is equivalent to the amplitude of the triangular carrier signal were used to generate the PWM signals. The inverter is capable of producing seven levels of output-voltage levels (Vdc, 2Vdc/3, Vdc/3, 0, .Vdc,.2Vdc/3,.Vdc/3) from the dc supply voltage. In this paper a new nine level multilevel inverter with reduced number of switches is proposed and MATLAB/Simulink results are presented.