DC-to-DC Solar Converter with Controlled Active Clamping System

Abstract

In the field of electrical solar power conversion efficiency is the most important topic. In most applications a special DC-to-DC converter is necessary to couple the solar cells, operating at low DC voltages, to the inverter's DC-link. These converters with rather low input respectively high output voltage ratings have, due to the high current ratings, a relatively low efficiency. Therefore, a special design is required to adapt the different voltage levels and fulfil the requirements of loss reduction. In this paper, a possible solution for such a specific solar converter is presented: a DC-to-DC converter with a controlled active snubber circuit. The input voltage of a (e.g. battery buffered) solar array (12 V or 24 V) is adapted to a 400 V DC-link, for a local grid power inverter supply. The total power to be managed on the output of the DC-to-DC converter is 500 W (12 V) respectively 1 kW (24 V) in our case. So it makes sense to develop a topology which is also well suited for paralleling several power switches. The structure presented here fulfills all of these topics