Efficiency of converters and amorphous core AC-filters in an LVDC distribution

This paper reports on an investigation of power losses of converters and amorphous core AC-filter inductors for a bipolar 750 V low voltage direct current (LVDC) distribution network, using electrical and calorimetric measurements. The LVDC network is a promising solution, which brings new opportunities to electricity distribution development. High power quality, reliability and high cost efficiency are typically the targets of the LVDC distribution. To progress these issues, the efficiency of a fully fledged LVDC laboratory prototype network is measured taking due account of grounding issues and customer´s behavior. As part of this research, accurate power loss calculation models of converters and filters have been developed. The efficiency of the LVDC network does not decrease at partial load when amorphous core filter inductors are used. However, the efficiency of the LVDC distribution network is lower than the present LVAC network, hence, methods of increasing the efficiency of future LVDC distribution networks, are addressed.