Composite DC Power Flow Controller

The utilization of a dc power flow controller in multiterminal HVDC (MTDC) can increase the control dimension of dc power flow, by which both the active power distribution capability and coordination control performance can be enhanced in MTDC. In this article, a novel concept of “composite dc power flow controller (CDCPFC)” has been proposed, and the general construction principles of technical frame have been given for function description. A specific CDCPFC topology has been implemented, which is featured with a straightforward dc-dc power conversion path via a transformerless structure. The operation principle, circuit characteristics, and control strategy of the proposed CDCPFC are analyzed in detail. Both simulation and experimental results proved that the proposed topology could realize power flow control function of two individual lines under various conditions with a good application prospect.