Common‐ground non‐isolated high‐gain DC/DC converter for low powerdistributed generation photovoltaic systems

Abstract

A high step-up/high-efficiency converter is one of the essential requirements of a low power grid-connected photovoltaic system that provides the maximum power point tracking ability and injects the low voltage extracted power to AC or DC distribution network. This study presents a common-ground non-isolated high-gain DC/DC converter whit a naturally wide range of soft-switching conditions. The proposed converter has two resonant loops, and a new simple structure consists of an active switch, three diodes, two inductors and two capacitors, work in two useful operation modes. In the optimum operation mode (OOM), the switch turns on/off in zero current switching (ZCS)/zero voltage switching condition, and at the sub-OOM, the switch turns on in ZCS condition and turns off in hard switching condition. The mathematical analysis and MATLAB/SIMULINK simulation results are described in detail. Also, a prototype 100 W converter is built and tested to validate the simulation analysis on a 100 W photovoltaic panel.