Losses of converters with iron and amorphous core AC-filter inductors in LVDC distribution

The power losses of three-level neutral-point-clamped (NPC) converters and their AC-filters with iron and amorphous core inductors designed for a bipolar low voltage direct current (LVDC) distribution network are evaluated. The main objectives of the LVDC distribution network are improved energy efficiency, power quality and reliability and higher power transmission capacity and integration of ICT devices and protection solutions in the converters. To progress the target of efficiency, the simple power loss simulation and calculation models have been developed. Utilizing the models, the effect of different grounding configuration and customer´s loads behavior on the power losses of an LVDC network is analyzed. Furthermore, the accuracy of the models is verified by means of laboratory measurements. According to the results, the amorphous inductor core should be used to obtain high efficiency in the LVDC distribution network.