Interleaved Operation of Quasi Z-Sources for Cascaded H-Bridge Multi Level Inverter

This paper presents an analytical and simulation-based study on the interleaved operation of quasi-Z-source (QZS) networks in a cascaded H-bridge multilevel inverter (CHB-MLI) topology. The focus is on demonstrating how interleaving two QZS networks reduces the voltage ripple (ΔV) across the DC link capacitors. In conventional QZS-CHB systems, significant voltage ripple can affect the stability and efficiency of power conversion. By introducing a phase shift between the operation of two identical QZS networks feeding a single H-bridge, the net ripple is effectively minimized due to partial cancellation of the ripple components. Simulation results obtained from MATLAB/Simulink validate the proposed concept, showing notable improvements in voltage stability and reduction in component stress. The analysis also compares the output voltage profiles of interleaved and non-interleaved QZS configurations.