Performance analysis of a new modular nano-crystalline core transformer based converter for medium voltage dc transmission applications

This paper proposes a new modular configuration for ac/dc conversion based on the concept of “building block” converter units. The modular system architecture comprises low-power units which can be connected in parallel to achieve higher power levels. Using such a design, medium voltage dc levels can be reached without the need of bulky step-up transformers or series connected switching devices. The converter configuration is introduced with its typical designed ratings and main features. Detailed design of the nano-crystalline core transformer is performed to verify size reduction. Simulation results for single and multi-module parallel operation are presented and discussed. Load current sharing between parallel modules is also investigated.