Design Considerations of 1.2kW Redundant Parallel DC/DC Power Supplies

This paper discussed the practical design considerations of the 1.2kW redundant power supplies. "N+1" redundant configuration is typically required for high reliability and robust fault-tolerance power supply systems. Current sharing among "N+1" power supplies can be employed to improve system performances. In this paper, paralleled multi-phase buck converters with the masterless average current sharing scheme along with an output voltage sensing scheme is employed to achieve a good output voltage regulation and fast-transient responses to load dynamics. However, several aspects must be considered when incorporating the current sharing and the output voltage sensing schemes into the redundant power supplis, especially during the fault-response conditions. The design considerations discussed in this paper mainly focus on the transient and fault conditions. A 1.2kW, 3+1 redundant power supply prototype is implemented to validate the design concept. Experiment results are presented and discussed.