With the continuous breakthrough in the capacity of power electronic devices and installations, the flexible DC transmission technology has been rapidly developed in recent years, and the DC grid formed on this basis has attracted much attention and is considered as a key technology to solve the problem of large-scale renewable energy consumption. In this paper, a high-voltage combined multiport DC/DC converter is proposed, the topology consists of an energy buffer arm used to transfer energy and a switching valve group composed of IGBTs connected in series with anti-parallel diodes. This structure has no AC link, does not require bulky magnetic components as well as transformers, and is characterized by low cost and small footprint. This paper describes the circuit structure, working principle, parameter design and working strategy. And simulati on cases of 250MW, 500kV/200kV/100kV are given to verify the effectiveness of the proposed topology.
Zhang et al. (Fri,) studied this question.