An Improved Z-Source Converter with Reduced Device Count for Utility Level PV System

In this paper, a modified Z-source (ZS) derived non-isolated high step-up DC-DC converter is proposed for efficient integration of low-voltage (LV) micro-sources such as solar PV, fuel cells, DC microgrids etc. Nonetheless, several high gain topologies proposed in the literature have limitations such as a limited voltage boosting factor, increased device voltage stress, inability to tolerate wide input voltage variations, increased device count, discontinuous input current, and so on. Considering the limits, a modified high gain converter is presented by adding two voltage multiplier cells (VMC) to the ZS converter to minimize device voltage stress and count. The presented converter provides improved conversion efficiency at lower duty ratios while maintaining continuous input current and sustaining output voltage under wide input variations. The detailed topological comparison is carried out. Furthermore, thermal modelling of the suggested converter is performed in PLECS Simulink platform to assess thermal loading under steady-state operation. Finally, simulation findings verify the theoretical statements.