Multi-level DC Power Distribution Interface for Data Centers

A DC power distribution interface for data centers is developed in this paper. This DC power distribution interface is composed of two power stages, a three-phase T-type multi-level AC-DC power converter and an isolated multi-level DC-DC power converter. The first power stage, three-phase T-type multi-level AC-DC power converter, is used to convert the utility AC voltage to a constant DC voltage and control the utility current to be sinusoidal and unity power factor. The isolated multi-level DC-DC power converter is the second power stage, and it converts the output DC voltage of the first power stage to the desired DC voltage of the DC power distribution system with galvanic isolation. This isolated multi-level DC-DC power converter consists of an isolated power converter with a three-winding transformer, a series/parallel switching circuit and an output L-C filter. Only three power electronics switches are used in the isolated multi-level DC-DC power converter to generate a two-level output DC voltage. Hence, the control circuit is simplified and the capacity of output L-C filter is reduced. Computer simulation is carried out to verify the developed DC power distribution interface. The simulation results show that the developed DC power distribution interface has the expected performance.