Comparative analysis of Synchronous Rectification Boost and Diode Rectification Boost converter for DMPPT applications

Photovoltaic systems performances are strongly influenced by mismatching phenomena. Such a drawback can be overcome by means of Distributed Maximum Power Point Tracking (DMPPT) which is based on the adoption of a DC-DC converter dedicated to the MPPT of each PV module. A DMPPT converter has to fulfil requirements of low complexity, high efficiency and high reliability. Many DC-DC converter topologies are available for DMPPT applications. The most widely used one is the boost converter. In this paper a comparative analysis between DMPPT Synchronous Rectification boost converter and Diode Rectification boost converter is carried out. Efficiency performance, thermal behaviour and reliability evaluation of the two converters power stages are compared by numerical and experimental data. The analysis demonstrates that the Synchronous Rectification boost converter is better for the PV system efficiency improvement and thermal requirements. The Diode Rectification boost instead is more reliable. A strategy to improve the Synchronous Rectification boost converter reliability is presented.