High performance non isolated interleaved switched inductance converter for PV sources

Abstract

The best way to avoid MPPT drawbacks due to mismatching phenomena is to use a dedicated DC/DC converter, in charge of MPPT, for each PV panel instead of a big central converter for the whole PV array. Dedicated DC/DC converters can be boost-like converters; they must be serially connected each other to obtain an higher voltage as required by the grid inverter. However, when the number of PV panels is relatively low, the sum of the voltages of the boost converters in a string may be insufficient to allow the inverter energy conversion function. In this paper a non isolated interleaved switched inductance converter is proposed and studied. Such a converter is characterized by a high voltage ratio and by a quite simple construction. A mathematical study of static characteristics of the proposed converter in both CCM and DCM conditions is provided together with the analytical estimation of losses. Moreover, the proposed converter has been compared, in terms of losses, with the dual stage synchronous boost converter.