A Capacitive Energy Transfer DC/DC Converter for HVDC Applications

High-voltage large-power DC/DC converter will be one of the pivotal equipment in the future direct-current power grid, and has become the hot topic of research in recent years. In this paper, a novel capacitive energy transfer (CET) DC/DC converter topology which applies to high voltage direct current (HVDC) is proposed. This topology is based on diodes in series, series-connected thyristors, and cascaded full-bridge submodules. The proposed converter has several merits such as simplicity, high efficiency, and low cost. Moreover, the bidirectional power transmission can be achieved by the coordinated control of fast mechanical disconnectors. The circuit structure, operation principle, parameter design, and control schemes of the topology are analyzed and proved by simulation results.