Series-connected DC-DC power converters for low-voltage dc source in distributed generation

Power conditioners for low-voltage DC sources in distributed generation usually have two major functions: to boost the energy source output voltage and to convert it into an AC voltage. The voltage boost is usually done by a DC-DC converter. This paper shows alternative topologies for standard DC-DC converters, in which the converter is series-connected with the source. The convenience of series-connected converters is evaluated by means of analytical results. Then, two standard DC-DC converters have been "re-designed" in series-connected versions and their operation has been evaluated in simulation: the switches peak current can be significantly reduced, thus reducing the costs and improving the energy source utilization.