Scalable shunt connected HVDC tap using the DC transformer concept

This paper describes the concept of a recently proposed scalable DC/DC converter topology applied to a shunt connected HVDC tap. This solution offers some advantages with respect to previously proposed solutions. Two different configurations of the circuit are proposed for interconnection with different HVDC systems. The internal structure of the modular DC/DC converter is presented and a suitable strategy to control the system is investigated in order to achieve soft-switching of the converter semiconductors. The operation is validated using computer simulations, which include a rough estimation of the DC/DC converter power losses.