A DC Power Distribution System in a Data Center using a Triple Active Bridge DC-DC Converter

In recent years, the demand for high-reliability systems has been on the rise, while DC power distribution systems are widely used in data centers. The authors propose a DC power distribution system that uses a triple active bridge (TAB) DC-DC converter, toward the realization of such higher-reliability systems. The TAB converter is based on an isolated DC-DC converter and can control the DC power flow among the three ports. First, this paper presents a basic power flow control procedure of the TAB converter, using a phase-shift control. Further, two types of higher-reliability DC power distribution systems are proposed using the TAB converter. The experimental design and simulations of a prototype 200-V TAB converter with 500-W power, connected with the single and double loads, are reported. In the experiment, the 200-V TAB converter rated at a power of 500W was constructed from a three-winding transformer and gallium nitride (GaN) power devices. Smooth output waveforms indicate good controllability of the power flow and good functional performance of the proposed DC power distribution system.