A High Step-Up Z-Source DC-DC Converter for Integration of Photovoltaic Panels into DC Microgrid

Abstract

This paper presents a Z-source-based high step-up DC-DC converter that benefits from high voltage gain, low voltage stress on the semiconductor devices and the capacitors. The switched-capacitor cells are integrated with the conventional Z-source impedance network resulting in a new high step-up DC-DC converter. The proposed converter is suitable for photovoltaic (PV) applications where PV panels are linked to a 400 V DC bus in a DC microgrid. The proposed converter reduces the voltage stress on the diodes and the power switch to less than half the output voltage and achieves a high-voltage gain without imposing a limitation on the duty cycle and requiring a large number of components. The operating principles, the steady-state analysis, and a comparison with other similar high step-up DC-DC converters are presented. The simulation and experimental results validate the performance and the applicability of the proposed converter.