Comparison between Two LCL DC Transformer Topologies: SCR-LCL and IGBT-LCL

The rise of HVDC use in power transmission is driven mainly by its increased efficiency and reduced cost when compared to conventional HVAC power transmission. However, HVAC power system are flexible regarding voltage level change, using AC transformers, when compared to HVDC systems. This paper will review two DC-DC transformer topologies, SCR-LCL, and IGBT-LCL. Those topologies show promise in accommodating high powers and voltages present in HVDC systems. In the review, the paper will consider the operational principles, design processes, and main types of power losses concerning each of the two topologies. In addition, it will mention other DC-DC topologies that are present in the literature.