A Single-stage High Boosting Ratio Converter for Grid-connected Photovoltaic Systems

摘要

In this article, a new single-stage high boosting ratio converter for grid-connected photovoltaic systems is proposed. The proposed system consists of a high voltage gain switched inductor buck-boost inverter that employs a folded cascade H-bridge circuit and operates at line frequency. The proposed system has a single switch operated with a sine wave modulation control. This applied control achieves maximum power point tracking of the input photovoltaic system in addition to the required injected sinusoidal grid current. The proposed system achieves the highest voltage boosting ratio of transformer-less topologies to the authors' best knowledge-more than ten times. In addition, it lowers switching losses and reduces the ground leakage current. A 150-W prototype with input voltage of 20 V and output voltage of 240 V has been developed with the purpose of obtaining experimental results and validating the proposed topology. Results report a boosting voltage gain of about ten times and system efficiency above 85%.